Programs & Examples On #Bea

0

Highlight Anchor Links when user manually scrolls?

You can use Jquery's on method and listen for the scroll event.

Are all Spring Framework Java Configuration injection examples buggy?

In your test, you are comparing the two TestParent beans, not the single TestedChild bean.

Also, Spring proxies your @Configuration class so that when you call one of the @Bean annotated methods, it caches the result and always returns the same object on future calls.

See here:

Got a NumberFormatException while trying to parse a text file for objects

The problem might be your split() call. Try just split(" ") without the square brackets.

Call japplet from jframe

First of all, Applets are designed to be run from within the context of a browser (or applet viewer), they're not really designed to be added into other containers.

Technically, you can add a applet to a frame like any other component, but personally, I wouldn't. The applet is expecting a lot more information to be available to it in order to allow it to work fully.

Instead, I would move all of the "application" content to a separate component, like a JPanel for example and simply move this between the applet or frame as required...

ps- You can use f.setLocationRelativeTo(null) to center the window on the screen ;)

Updated

You need to go back to basics. Unless you absolutely must have one, avoid applets until you understand the basics of Swing, case in point...

Within the constructor of GalzyTable2 you are doing...

JApplet app = new JApplet(); add(app); app.init(); app.start(); 

...Why are you adding another applet to an applet??

Case in point...

Within the main method, you are trying to add the instance of JFrame to itself...

f.getContentPane().add(f, button2); 

Instead, create yourself a class that extends from something like JPanel, add your UI logical to this, using compound components if required.

Then, add this panel to whatever top level container you need.

Take the time to read through Creating a GUI with Swing

Updated with example

import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.EventQueue; import java.awt.event.ActionEvent; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTable; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException;  public class GalaxyTable2 extends JPanel {      private static final int PREF_W = 700;     private static final int PREF_H = 600;      String[] columnNames                     = {"Phone Name", "Brief Description", "Picture", "price",                         "Buy"};  // Create image icons     ImageIcon Image1 = new ImageIcon(                     getClass().getResource("s1.png"));     ImageIcon Image2 = new ImageIcon(                     getClass().getResource("s2.png"));     ImageIcon Image3 = new ImageIcon(                     getClass().getResource("s3.png"));     ImageIcon Image4 = new ImageIcon(                     getClass().getResource("s4.png"));     ImageIcon Image5 = new ImageIcon(                     getClass().getResource("note.png"));     ImageIcon Image6 = new ImageIcon(                     getClass().getResource("note2.png"));     ImageIcon Image7 = new ImageIcon(                     getClass().getResource("note3.png"));      Object[][] rowData = {         {"Galaxy S", "3G Support,CPU 1GHz",             Image1, 120, false},         {"Galaxy S II", "3G Support,CPU 1.2GHz",             Image2, 170, false},         {"Galaxy S III", "3G Support,CPU 1.4GHz",             Image3, 205, false},         {"Galaxy S4", "4G Support,CPU 1.6GHz",             Image4, 230, false},         {"Galaxy Note", "4G Support,CPU 1.4GHz",             Image5, 190, false},         {"Galaxy Note2 II", "4G Support,CPU 1.6GHz",             Image6, 190, false},         {"Galaxy Note 3", "4G Support,CPU 2.3GHz",             Image7, 260, false},};      MyTable ss = new MyTable(                     rowData, columnNames);      // Create a table     JTable jTable1 = new JTable(ss);      public GalaxyTable2() {         jTable1.setRowHeight(70);          add(new JScrollPane(jTable1),                         BorderLayout.CENTER);          JPanel buttons = new JPanel();          JButton button = new JButton("Home");         buttons.add(button);         JButton button2 = new JButton("Confirm");         buttons.add(button2);          add(buttons, BorderLayout.SOUTH);     }      @Override      public Dimension getPreferredSize() {         return new Dimension(PREF_W, PREF_H);     }      public void actionPerformed(ActionEvent e) {         new AMainFrame7().setVisible(true);     }      public static void main(String[] args) {          EventQueue.invokeLater(new Runnable() {             @Override             public void run() {                 try {                     UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());                 } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {                     ex.printStackTrace();                 }                  JFrame frame = new JFrame("Testing");                 frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);                 frame.add(new GalaxyTable2());                 frame.pack();                 frame.setLocationRelativeTo(null);                 frame.setVisible(true);             }         });     } } 

You also seem to have a lack of understanding about how to use layout managers.

Take the time to read through Creating a GUI with Swing and Laying components out in a container

Schema validation failed with the following errors: Data path ".builders['app-shell']" should have required property 'class'

This is worked for me

  1. npm uninstall @angular-devkit/build-angular
  2. npm install @angular-devkit/[email protected]

Access blocked by CORS policy: Response to preflight request doesn't pass access control check

CORS headers should be sent from the server. If you use PHP it will be like this:

header('Access-Control-Allow-Origin: your-host');
header('Access-Control-Allow-Credentials: true');
header('Access-Control-Allow-Methods: your-methods like POST,GET');
header('Access-Control-Allow-Headers: content-type or other');
header('Content-Type: application/json');

UnhandledPromiseRejectionWarning: This error originated either by throwing inside of an async function without a catch block

I resolve the problem. It's very simple . if do you checking care the problem may be because the auxiliar variable has whitespace. Why ? I don't know but yus must use the trim() method and will resolve the problem

Scraping: SSL: CERTIFICATE_VERIFY_FAILED error for http://en.wikipedia.org

Two steps worked for me : - going Macintosh HD > Applications > Python3.7 folder - click on "Install Certificates.command"

ApplicationContextException: Unable to start ServletWebServerApplicationContext due to missing ServletWebServerFactory bean

  1. @SpringBootApplication: checked, didn't work.
  2. spring-boot-starter-web in Pom file: checked, didn't work.
  3. Switch from IntelliJ CE to IntelliJ Ultimate, problem solved.

Axios handling errors

You can go like this: error.response.data
In my case, I got error property from backend. So, I used error.response.data.error

My code:

axios
  .get(`${API_BASE_URL}/students`)
  .then(response => {
     return response.data
  })
  .then(data => {
     console.log(data)
  })
  .catch(error => {
     console.log(error.response.data.error)
  })

After Spring Boot 2.0 migration: jdbcUrl is required with driverClassName

Your can use DataSourceBuilder for this purpose.

@Primary
@Bean(name = "dataSource")
@ConfigurationProperties(prefix = "spring.datasource")
public DataSource dataSource(Environment env) {
    final String datasourceUsername = env.getRequiredProperty("spring.datasource.username");
    final String datasourcePassword = env.getRequiredProperty("spring.datasource.password");
    final String datasourceUrl = env.getRequiredProperty("spring.datasource.url");
    final String datasourceDriver = env.getRequiredProperty("spring.datasource.driver-class-name");
    return DataSourceBuilder
            .create()
            .username(datasourceUsername)
            .password(datasourcePassword)
            .url(datasourceUrl)
            .driverClassName(datasourceDriver)
            .build();
}

Not able to pip install pickle in python 3.6

$ pip install pickle5
import pickle5 as pickle

pb = pickle.PickleBuffer(b"foo")
data = pickle.dumps(pb, protocol=5)
assert pickle.loads(data) == b"foo"

This package backports all features and APIs added in the pickle module in Python 3.8.3, including the PEP 574 additions. It should work with Python 3.5, 3.6 and 3.7.

Basic usage is similar to the pickle module, except that the module to be imported is pickle5:

https://pypi.org/project/pickle5/

Python convert object to float

I eventually used:

weather["Temp"] = weather["Temp"].convert_objects(convert_numeric=True)

It worked just fine, except that I got the following message.

C:\ProgramData\Anaconda3\lib\site-packages\ipykernel_launcher.py:3: FutureWarning:
convert_objects is deprecated.  Use the data-type specific converters pd.to_datetime, pd.to_timedelta and pd.to_numeric.

How to debug when Kubernetes nodes are in 'Not Ready' state

I found applying the network and rebooting both the nodes did the trick for me.

kubectl apply -f [podnetwork].yaml

How to sign in kubernetes dashboard?

As of release 1.7 Dashboard supports user authentication based on:

Dashboard on Github

Token

Here Token can be Static Token, Service Account Token, OpenID Connect Token from Kubernetes Authenticating, but not the kubeadm Bootstrap Token.

With kubectl, we can get an service account (eg. deployment controller) created in kubernetes by default.

$ kubectl -n kube-system get secret
# All secrets with type 'kubernetes.io/service-account-token' will allow to log in.
# Note that they have different privileges.
NAME                                     TYPE                                  DATA      AGE
deployment-controller-token-frsqj        kubernetes.io/service-account-token   3         22h

$ kubectl -n kube-system describe secret deployment-controller-token-frsqj
Name:         deployment-controller-token-frsqj
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name=deployment-controller
              kubernetes.io/service-account.uid=64735958-ae9f-11e7-90d5-02420ac00002

Type:  kubernetes.io/service-account-token

Data
====
ca.crt:     1025 bytes
namespace:  11 bytes
token:      eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.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.OqFc4CE1Kh6T3BTCR4XxDZR8gaF1MvH4M3ZHZeCGfO-sw-D0gp826vGPHr_0M66SkGaOmlsVHmP7zmTi-SJ3NCdVO5viHaVUwPJ62hx88_JPmSfD0KJJh6G5QokKfiO0WlGN7L1GgiZj18zgXVYaJShlBSz5qGRuGf0s1jy9KOBt9slAN5xQ9_b88amym2GIXoFyBsqymt5H-iMQaGP35tbRpewKKtly9LzIdrO23bDiZ1voc5QZeAZIWrizzjPY5HPM1qOqacaY9DcGc7akh98eBJG_4vZqH2gKy76fMf0yInFTeNKr45_6fWt8gRM77DQmPwb3hbrjWXe1VvXX_g

Kubeconfig

The dashboard needs the user in the kubeconfig file to have either username & password or token, but admin.conf only has client-certificate. You can edit the config file to add the token that was extracted using the method above.

$ kubectl config set-credentials cluster-admin --token=bearer_token

Alternative (Not recommended for Production)

Here are two ways to bypass the authentication, but use for caution.

Deploy dashboard with HTTP

$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/master/src/deploy/alternative/kubernetes-dashboard.yaml

Dashboard can be loaded at http://localhost:8001/ui with kubectl proxy.

Granting admin privileges to Dashboard's Service Account

$ cat <<EOF | kubectl create -f -
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
  name: kubernetes-dashboard
  labels:
    k8s-app: kubernetes-dashboard
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: kubernetes-dashboard
  namespace: kube-system
EOF

Afterwards you can use Skip option on login page to access Dashboard.

If you are using dashboard version v1.10.1 or later, you must also add --enable-skip-login to the deployment's command line arguments. You can do so by adding it to the args in kubectl edit deployment/kubernetes-dashboard --namespace=kube-system.

Example:

      containers:
      - args:
        - --auto-generate-certificates
        - --enable-skip-login            # <-- add this line
        image: k8s.gcr.io/kubernetes-dashboard-amd64:v1.10.1

Can't create project on Netbeans 8.2

I had the same problem I installed NetBeans 8.2 on macOS High Sierra, and by default settings, NetBeans will work with the latest JDK release (currently JDK 9).

NetBeans Problem

What I did was forcing NetBeans to use JDK 8, you must config your netbeans.conf file, you can find it on:

/Applications/NetBeans/NetBeans 8.2.app/Contents/Resources/NetBeans/etc/netbeans.conf

enter image description here

You need to uncomment and update your path to JDK, you will find yours at:

/Library/Java/JavaVirtualMachines/jdk1.8.0_131.jdk/Contents/Home

enter image description here

Just save it, restart NetBeans and you are done!

No String-argument constructor/factory method to deserialize from String value ('')

Had this when I accidentally was calling

mapper.convertValue(...)

instead of

mapper.readValue(...)

So, just make sure you call correct method, since argument are same and IDE can find many things

Java.lang.NoClassDefFoundError: com/fasterxml/jackson/databind/exc/InvalidDefinitionException

Use all the jackson dependencies(databind,core, annotations, scala(if you are using spark and scala)) with the same version.. and upgrade the versions to the latest releases..

<dependency>
            <groupId>com.fasterxml.jackson.module</groupId>
            <artifactId>jackson-module-scala_2.11</artifactId>
            <version>2.9.4</version>
        </dependency>

        <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.4</version>
        <exclusions>
            <exclusion>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-core</artifactId>
            </exclusion>
            <exclusion>
                <groupId>com.fasterxml.jackson.core</groupId>
                <artifactId>jackson-annotations</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.9.4</version>
    </dependency>

        <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.9.4</version>

        </dependency>

Note: Use Scala dependency only if you are working with scala. Otherwise it is not needed.

How to completely uninstall kubernetes

If you are clearing the cluster so that you can start again, then, in addition to what @rib47 said, I also do the following to ensure my systems are in a state ready for kubeadm init again:

kubeadm reset -f
rm -rf /etc/cni /etc/kubernetes /var/lib/dockershim /var/lib/etcd /var/lib/kubelet /var/run/kubernetes ~/.kube/*
iptables -F && iptables -X
iptables -t nat -F && iptables -t nat -X
iptables -t raw -F && iptables -t raw -X
iptables -t mangle -F && iptables -t mangle -X
systemctl restart docker

You then need to re-install docker.io, kubeadm, kubectl, and kubelet to make sure they are at the latest versions for your distribution before you re-initialize the cluster.

EDIT: Discovered that calico adds firewall rules to the raw table so that needs clearing out as well.

How to send authorization header with axios

Try this :

axios.get(
    url,
    {headers: {
        "name" : "value"
      }
    }
  )
  .then((response) => {
      var response = response.data;
    },
    (error) => {
      var status = error.response.status
    }
  );

RestClientException: Could not extract response. no suitable HttpMessageConverter found

I was trying to use Feign, while I encounter same issue, As I understood HTTP message converter will help but wanted to understand how to achieve this.

@FeignClient(name = "mobilesearch", url = "${mobile.search.uri}" ,
        fallbackFactory = MobileSearchFallbackFactory.class,
        configuration = MobileSearchFeignConfig.class)
public interface MobileSearchClient {

    @RequestMapping(method = RequestMethod.GET)
    List<MobileSearchResponse> getPhones();
}

You have to use Customer Configuration for the decoder, MobileSearchFeignConfig,

public class MobileSearchFeignConfig {

    @Bean
    Logger.Level feignLoggerLevel() {
        return Logger.Level.FULL;
    }


    @Bean
    public Decoder feignDecoder() {
        return new ResponseEntityDecoder(new SpringDecoder(feignHttpMessageConverter()));
    }

    public ObjectFactory<HttpMessageConverters> feignHttpMessageConverter() {
        final HttpMessageConverters httpMessageConverters = new HttpMessageConverters(new MappingJackson2HttpMessageConverter());
        return new ObjectFactory<HttpMessageConverters>() {
            @Override
            public HttpMessageConverters getObject() throws BeansException {
                return httpMessageConverters;
            }
        };
    }

    public class MappingJackson2HttpMessageConverter extends org.springframework.http.converter.json.MappingJackson2HttpMessageConverter {
        MappingJackson2HttpMessageConverter() {
            List<MediaType> mediaTypes = new ArrayList<>();
            mediaTypes.add(MediaType.valueOf(MediaType.TEXT_HTML_VALUE + ";charset=UTF-8"));
            setSupportedMediaTypes(mediaTypes);
        }
    }

}

The origin server did not find a current representation for the target resource or is not willing to disclose that one exists

Accessing webpages issues

I added yellow highlighted package and now my view page is accessible. in eclipse when we deploy our war it only deploy those stuff mention in the deployment assessment.

We set Deployment Assessment from right click on project --> Properties --> Apply and Close....

The origin server did not find a current representation for the target resource or is not willing to disclose that one exists. on deploying to tomcat

I've received the same error when working in a Spring Boot Application because when running as Spring Boot, it's easy to do localhost:8080/hello/World but when you've built the artifact and deployed to Tomcat, then you need to switch to using localhost:8080/<artifactName>/hello/World

How to check if a key exists in Json Object and get its value

Please try this one..

JSONObject jsonObject= null;
try {
     jsonObject = new JSONObject("result........");
     String labelDataString=jsonObject.getString("LabelData");
     JSONObject labelDataJson= null;
     labelDataJson= new JSONObject(labelDataString);
     if(labelDataJson.has("video")&&labelDataJson.getString("video")!=null){
       String video=labelDataJson.getString("video");
     }
    } catch (JSONException e) {
      e.printStackTrace();
 }

Export result set on Dbeaver to CSV

The problem was the box "open new connection" that was checked. So I couldn't use my temporary table.

Running Tensorflow in Jupyter Notebook

It is better to create new environment with new name ($newenv):conda create -n $newenv tensorflow

Then by using anaconda navigator under environment tab you can find newenv in the middle column.

By clicking on the play button open terminal and type: activate tensorflow

Then install tensorflow inside the newenv by typing: pip install tensorflow

Now you have tensorflow inside the new environment so then install jupyter by typing: pip install jupyter notebook

Then just simply type: jupyter notebook to run the jupyter notebook.

Inside of the jupyter notebook type: import tensorflow as tf

To test the the tf you can use THIS LINK

'Field required a bean of type that could not be found.' error spring restful API using mongodb

I have same Issue, fixed by Adding @EnableMongoRepositories("in.topthree.util")

package in.topthree.core;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.mongodb.repository.config.EnableMongoRepositories;

import in.topthree.util.Student;

@SpringBootApplication
@EnableMongoRepositories("in.topthree.util")
public class Run implements CommandLineRunner {

    public static void main(String[] args) {
        SpringApplication.run(Run.class, args);
        System.out.println("Run");
    }

    @Autowired
    private Process pr;

    @Override
    public void run(String... args) throws Exception {
        pr.saveDB(new Student("Testing", "FB"));
        System.exit(0);
    }

}

And my Repository is:

package in.topthree.util;

import org.springframework.data.mongodb.repository.MongoRepository;

public interface StudentMongo extends MongoRepository<Student, Integer> {

    public Student findByUrl(String url);
}

Now Its Working

Vertical Align Center in Bootstrap 4

<!DOCTYPE html>
<html lang="en">
<head>
  <title>Bootstrap Example</title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.2.1/css/bootstrap.min.css">
  <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.6/umd/popper.min.js"></script>
  <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.2.1/js/bootstrap.min.js"></script>
</head>
<body>  
<div class="container">
    <div class="row align-items-center justify-content-center" style="height:100vh;">     
         <div>Center Div Here</div>
    </div>
</div>
</body>
</html>

CORS error :Request header field Authorization is not allowed by Access-Control-Allow-Headers in preflight response

For anyone getting this using ServiceStack backend; add "Authorization" to allowed headers in the Cors plugin:

Plugins.Add(new CorsFeature(allowedHeaders: "Content-Type,Authorization"));

MultipartException: Current request is not a multipart request

I was also facing the same issue with Postman for multipart. I fixed it by doing the following steps:

  • Do not select Content-Type in the Headers section.
  • In Body tab of Postman you should select form-data and select file type.

It worked for me.

Error starting ApplicationContext. To display the auto-configuration report re-run your application with 'debug' enabled

I added @Component annotation from import org.springframework.stereotype.Component and the problem was solved.

ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749)

I ran this on MacOS /Applications/Python\ 3.6/Install\ Certificates.command

Consider defining a bean of type 'service' in your configuration [Spring boot]

I fixed the problem adding this line @ComponentScan(basePackages = {"com.example.DemoApplication"}) to main class file, just up from the class name

_x000D_
_x000D_
package com.example.demo;_x000D_
_x000D_
import org.springframework.boot.SpringApplication;_x000D_
import org.springframework.boot.autoconfigure.SpringBootApplication;_x000D_
import org.springframework.context.annotation.ComponentScan;_x000D_
_x000D_
@SpringBootApplication_x000D_
@ComponentScan(basePackages = {"com.example.DemoApplication"})_x000D_
public class DemoApplication {_x000D_
_x000D_
 public static void main(String[] args) {_x000D_
  SpringApplication.run(DemoApplication.class, args);_x000D_
 }_x000D_
_x000D_
}
_x000D_
_x000D_
_x000D_

Using Axios GET with Authorization Header in React-Native App

For anyone else that comes across this post and might find it useful... There is actually nothing wrong with my code. I made the mistake of requesting client_credentials type access code instead of password access code (#facepalms). FYI I am using urlencoded post hence the use of querystring.. So for those that may be looking for some example code.. here is my full request

Big thanks to @swapnil for trying to help me debug this.

   const data = {
      grant_type: USER_GRANT_TYPE,
      client_id: CLIENT_ID,
      client_secret: CLIENT_SECRET,
      scope: SCOPE_INT,
      username: DEMO_EMAIL,
      password: DEMO_PASSWORD
    };



  axios.post(TOKEN_URL, Querystring.stringify(data))   
   .then(response => {
      console.log(response.data);
      USER_TOKEN = response.data.access_token;
      console.log('userresponse ' + response.data.access_token); 
    })   
   .catch((error) => {
      console.log('error ' + error);   
   });



const AuthStr = 'Bearer '.concat(USER_TOKEN); 
axios.get(URL, { headers: { Authorization: AuthStr } })
 .then(response => {
     // If request is good...
     console.log(response.data);
  })
 .catch((error) => {
     console.log('error ' + error);
  });

UnsatisfiedDependencyException: Error creating bean with name

The application needs to be placed in the same directory as the scanned package:

enter image description here

Caused by: org.flywaydb.core.api.FlywayException: Validate failed. Migration Checksum mismatch for migration 2

The best solution would be to do these steps :

  1. Delete the file called - V2__create_shipwreck.sql, clean and build the project again.
  2. Run the project again, login into h2 and delete the table called "schema_version".

    drop table schema_version;

  3. Now make V2__create_shipwreck.sql file with ddl and rerun the project again.

  4. Do remember this, add version 4.1.2 for flyway-core in pom.xml like

    <dependency>
        <groupId>org.flywaydb</groupId>
        <artifactId>flyway-core</artifactId>
        <version>4.1.2</version>
    </dependency>
    

It should work now. Hope this will help.

Vue - Deep watching an array of objects and calculating the change?

It is well defined behaviour. You cannot get the old value for a mutated object. That's because both the newVal and oldVal refer to the same object. Vue will not keep an old copy of an object that you mutated.

Had you replaced the object with another one, Vue would have provided you with correct references.

Read the Note section in the docs. (vm.$watch)

More on this here and here.

Sending the bearer token with axios

The second parameter of axios.post is data (not config). config is the third parameter. Please see this for details: https://github.com/mzabriskie/axios#axiosposturl-data-config

Changing background color of selected item in recyclerview

Most Simpler Way From My Side is to Add a variable in adapterPage as last Clicked Position.

in onBindViewHolder paste this code which checks for last stored position matched with loading positions Constants is the class where i declare my global variables

if(Constants.LAST_SELECTED_POSITION_SINGLE_PRODUCT == position) {

    //change the view background here
    holder.colorVariantThumb.setBackgroundResource(R.drawable.selected_background);
}

//on view click you store the position value and notifyItemRangeChanged will 
// call the onBindViewHolder and will check the condition

holder.itemView.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view){
        Constants.LAST_SELECTED_POSITION_SINGLE_PRODUCT=position;
        notifyItemRangeChanged(0, mColorVariants.size());
    } 
});

Spring security CORS Filter

There's 8 hours of my life I will never get back...

Make sure that you set both Exposed Headers AND Allowed Headers in your CorsConfiguration

@Bean
CorsConfigurationSource corsConfigurationSource() {
    CorsConfiguration configuration = new CorsConfiguration();
    configuration.setAllowedOrigins(Collections.singletonList("http://localhost:3000"));
    configuration.setAllowedMethods(Arrays.asList("GET","POST", "PUT", "DELETE", "PATCH", "OPTIONS"));
    configuration.setExposedHeaders(Arrays.asList("Authorization", "content-type"));
    configuration.setAllowedHeaders(Arrays.asList("Authorization", "content-type"));
    UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
    source.registerCorsConfiguration("/**", configuration);
    return source;
}

Consider defining a bean of type 'package' in your configuration [Spring-Boot]

If your class dependency is managing by Spring then this issue may occur if we forgot to add default/empty arg constructor inside our POJO class.

JWT authentication for ASP.NET Web API

I answered this question: How to secure an ASP.NET Web API 4 years ago using HMAC.

Now, lots of things changed in security, especially that JWT is getting popular. In this answer, I will try to explain how to use JWT in the simplest and basic way that I can, so we won't get lost from jungle of OWIN, Oauth2, ASP.NET Identity... :)

If you don't know about JWT tokens, you need to take a look at:

https://tools.ietf.org/html/rfc7519

Basically, a JWT token looks like this:

<base64-encoded header>.<base64-encoded claims>.<base64-encoded signature>

Example:

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1bmlxdWVfbmFtZSI6ImN1b25nIiwibmJmIjoxNDc3NTY1NzI0LCJleHAiOjE0Nzc1NjY5MjQsImlhdCI6MTQ3NzU2NTcyNH0.6MzD1VwA5AcOcajkFyKhLYybr3h13iZjDyHm9zysDFQ

A JWT token has three sections:

  1. Header: JSON format which is encoded in Base64
  2. Claims: JSON format which is encoded in Base64.
  3. Signature: Created and signed based on Header and Claims which is encoded in Base64.

If you use the website jwt.io with the token above, you can decode the token and see it like below:

A screenshot of jwt.io with the raw jwt source and the decoded JSON it represents

Technically, JWT uses a signature which is signed from headers and claims with security algorithm specified in the headers (example: HMACSHA256). Therefore, JWT must be transferred over HTTPs if you store any sensitive information in its claims.

Now, in order to use JWT authentication, you don't really need an OWIN middleware if you have a legacy Web Api system. The simple concept is how to provide JWT token and how to validate the token when the request comes. That's it.

In the demo I've created (github), to keep the JWT token lightweight, I only store username and expiration time. But this way, you have to re-build new local identity (principal) to add more information like roles, if you want to do role authorization, etc. But, if you want to add more information into JWT, it's up to you: it's very flexible.

Instead of using OWIN middleware, you can simply provide a JWT token endpoint by using a controller action:

public class TokenController : ApiController
{
    // This is naive endpoint for demo, it should use Basic authentication
    // to provide token or POST request
    [AllowAnonymous]
    public string Get(string username, string password)
    {
        if (CheckUser(username, password))
        {
            return JwtManager.GenerateToken(username);
        }

        throw new HttpResponseException(HttpStatusCode.Unauthorized);
    }

    public bool CheckUser(string username, string password)
    {
        // should check in the database
        return true;
    }
}

This is a naive action; in production you should use a POST request or a Basic Authentication endpoint to provide the JWT token.

How to generate the token based on username?

You can use the NuGet package called System.IdentityModel.Tokens.Jwt from Microsoft to generate the token, or even another package if you like. In the demo, I use HMACSHA256 with SymmetricKey:

/// <summary>
/// Use the below code to generate symmetric Secret Key
///     var hmac = new HMACSHA256();
///     var key = Convert.ToBase64String(hmac.Key);
/// </summary>
private const string Secret = "db3OIsj+BXE9NZDy0t8W3TcNekrF+2d/1sFnWG4HnV8TZY30iTOdtVWJG8abWvB1GlOgJuQZdcF2Luqm/hccMw==";

public static string GenerateToken(string username, int expireMinutes = 20)
{
    var symmetricKey = Convert.FromBase64String(Secret);
    var tokenHandler = new JwtSecurityTokenHandler();

    var now = DateTime.UtcNow;
    var tokenDescriptor = new SecurityTokenDescriptor
    {
        Subject = new ClaimsIdentity(new[]
        {
            new Claim(ClaimTypes.Name, username)
        }),

        Expires = now.AddMinutes(Convert.ToInt32(expireMinutes)),
        
        SigningCredentials = new SigningCredentials(
            new SymmetricSecurityKey(symmetricKey), 
            SecurityAlgorithms.HmacSha256Signature)
    };

    var stoken = tokenHandler.CreateToken(tokenDescriptor);
    var token = tokenHandler.WriteToken(stoken);

    return token;
}

The endpoint to provide the JWT token is done.

How to validate the JWT when the request comes?

In the demo, I have built JwtAuthenticationAttribute which inherits from IAuthenticationFilter (more detail about authentication filter in here).

With this attribute, you can authenticate any action: you just have to put this attribute on that action.

public class ValueController : ApiController
{
    [JwtAuthentication]
    public string Get()
    {
        return "value";
    }
}

You can also use OWIN middleware or DelegateHander if you want to validate all incoming requests for your WebAPI (not specific to Controller or action)

Below is the core method from authentication filter:

private static bool ValidateToken(string token, out string username)
{
    username = null;

    var simplePrinciple = JwtManager.GetPrincipal(token);
    var identity = simplePrinciple.Identity as ClaimsIdentity;

    if (identity == null)
        return false;

    if (!identity.IsAuthenticated)
        return false;

    var usernameClaim = identity.FindFirst(ClaimTypes.Name);
    username = usernameClaim?.Value;

    if (string.IsNullOrEmpty(username))
       return false;

    // More validate to check whether username exists in system

    return true;
}

protected Task<IPrincipal> AuthenticateJwtToken(string token)
{
    string username;

    if (ValidateToken(token, out username))
    {
        // based on username to get more information from database 
        // in order to build local identity
        var claims = new List<Claim>
        {
            new Claim(ClaimTypes.Name, username)
            // Add more claims if needed: Roles, ...
        };

        var identity = new ClaimsIdentity(claims, "Jwt");
        IPrincipal user = new ClaimsPrincipal(identity);

        return Task.FromResult(user);
    }

    return Task.FromResult<IPrincipal>(null);
}

The workflow is to use the JWT library (NuGet package above) to validate the JWT token and then return back ClaimsPrincipal. You can perform more validation, like check whether user exists on your system, and add other custom validations if you want.

The code to validate JWT token and get principal back:

public static ClaimsPrincipal GetPrincipal(string token)
{
    try
    {
        var tokenHandler = new JwtSecurityTokenHandler();
        var jwtToken = tokenHandler.ReadToken(token) as JwtSecurityToken;

        if (jwtToken == null)
            return null;

        var symmetricKey = Convert.FromBase64String(Secret);

        var validationParameters = new TokenValidationParameters()
        {
            RequireExpirationTime = true,
            ValidateIssuer = false,
            ValidateAudience = false,
            IssuerSigningKey = new SymmetricSecurityKey(symmetricKey)
        };

        SecurityToken securityToken;
        var principal = tokenHandler.ValidateToken(token, validationParameters, out securityToken);

        return principal;
    }
    catch (Exception)
    {
        //should write log
        return null;
    }
}

If the JWT token is validated and the principal is returned, you should build a new local identity and put more information into it to check role authorization.

Remember to add config.Filters.Add(new AuthorizeAttribute()); (default authorization) at global scope in order to prevent any anonymous request to your resources.

You can use Postman to test the demo:

Request token (naive as I mentioned above, just for demo):

GET http://localhost:{port}/api/token?username=cuong&password=1

Put JWT token in the header for authorized request, example:

GET http://localhost:{port}/api/value

Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1bmlxdWVfbmFtZSI6ImN1b25nIiwibmJmIjoxNDc3NTY1MjU4LCJleHAiOjE0Nzc1NjY0NTgsImlhdCI6MTQ3NzU2NTI1OH0.dSwwufd4-gztkLpttZsZ1255oEzpWCJkayR_4yvNL1s

The demo can be found here: https://github.com/cuongle/WebApi.Jwt

8080 port already taken issue when trying to redeploy project from Spring Tool Suite IDE

Goto Window->Preferences, search for Launching.

Select the "Terminate and Relaunch while launching" option.

Press Apply.

Error creating bean with name 'entityManagerFactory' defined in class path resource : Invocation of init method failed

People using Java 9 include this dependency:

<dependency>
    <groupId>javax.xml.bind</groupId>
    <artifactId>jaxb-api</artifactId>
    <version>2.3.0</version>
</dependency>

What are the main differences between JWT and OAuth authentication?

JWT is an open standard that defines a compact and self-contained way for securely transmitting information between parties. It is an authentication protocol where we allow encoded claims (tokens) to be transferred between two parties (client and server) and the token is issued upon the identification of a client. With each subsequent request we send the token.

Whereas OAuth2 is an authorization framework, where it has a general procedures and setups defined by the framework. JWT can be used as a mechanism inside OAuth2.

You can read more on this here

OAuth or JWT? Which one to use and why?

How to beautifully update a JPA entity in Spring Data?

Even better then @Tanjim Rahman answer you can using Spring Data JPA use the method T getOne(ID id)

Customer customerToUpdate = customerRepository.getOne(id);
customerToUpdate.setName(customerDto.getName);
customerRepository.save(customerToUpdate);

Is's better because getOne(ID id) gets you only a reference (proxy) object and does not fetch it from the DB. On this reference you can set what you want and on save() it will do just an SQL UPDATE statement like you expect it. In comparsion when you call find() like in @Tanjim Rahmans answer spring data JPA will do an SQL SELECT to physically fetch the entity from the DB, which you dont need, when you are just updating.

Apache POI error loading XSSFWorkbook class

If you have downloaded pio-3.17 On eclipse: right click on the project folder -> build path -> configure build path -> libraries -> add external jars -> add all the commons jar file from the "lib". It's worked for me.

How do you format code on save in VS Code

As of September 2016 (VSCode 1.6), this is now officially supported.

Add the following to your settings.json file:

"editor.formatOnSave": true

Correctly Parsing JSON in Swift 3

{
    "User":[
      {
        "FirstUser":{
        "name":"John"
        },
       "Information":"XY",
        "SecondUser":{
        "name":"Tom"
      }
     }
   ]
}

If I create model using previous json Using this link [blog]: http://www.jsoncafe.com to generate Codable structure or Any Format

Model

import Foundation
struct RootClass : Codable {
    let user : [Users]?
    enum CodingKeys: String, CodingKey {
        case user = "User"
    }

    init(from decoder: Decoder) throws {
        let values = try? decoder.container(keyedBy: CodingKeys.self)
        user = try? values?.decodeIfPresent([Users].self, forKey: .user)
    }
}

struct Users : Codable {
    let firstUser : FirstUser?
    let information : String?
    let secondUser : SecondUser?
    enum CodingKeys: String, CodingKey {
        case firstUser = "FirstUser"
        case information = "Information"
        case secondUser = "SecondUser"
    }
    init(from decoder: Decoder) throws {
        let values = try? decoder.container(keyedBy: CodingKeys.self)
        firstUser = try? FirstUser(from: decoder)
        information = try? values?.decodeIfPresent(String.self, forKey: .information)
        secondUser = try? SecondUser(from: decoder)
    }
}
struct SecondUser : Codable {
    let name : String?
    enum CodingKeys: String, CodingKey {
        case name = "name"
    }
    init(from decoder: Decoder) throws {
        let values = try? decoder.container(keyedBy: CodingKeys.self)
        name = try? values?.decodeIfPresent(String.self, forKey: .name)
    }
}
struct FirstUser : Codable {
    let name : String?
    enum CodingKeys: String, CodingKey {
        case name = "name"
    }
    init(from decoder: Decoder) throws {
        let values = try? decoder.container(keyedBy: CodingKeys.self)
        name = try? values?.decodeIfPresent(String.self, forKey: .name)
    }
}

Parse

    do {
        let res = try JSONDecoder().decode(RootClass.self, from: data)
        print(res?.user?.first?.firstUser?.name ?? "Yours optional value")
    } catch {
        print(error)
    }

How can I change the user on Git Bash?

For any OS

This helped me so I'll put it here, just in case. Once you are done with adding the rsa keys for both the accounts, add a config file in your .ssh directory for both the accounts (.ssh/config)

# First account
Host github.com-<FIRST_ACCOUNT_USERNAME_HERE>
   HostName github.com
   User git
   IdentityFile ~/.ssh/id_rsa_user1
   
# Second account
Host github.com-<SECOND_ACCOUNT_USERNAME_HERE>   
   HostName github.com
   User git
   IdentityFile ~/.ssh/id_rsa_user2

Make sure you use the correct usernames and RSA files. Next, you can open the terminal/git bash on the repository root and check which account you would be pushing from

git config user.email

Suppose this returns the first user email and you want to push from the second user. Change the local user.name and user.email :

git config user.name "SECOND_USER"
git config user.email "[email protected]"

(This won't change the global config and you can have the first user set up as the global user). Once done, you can confirm with git config user.email and it should return the email of the second user. You're all set to push to GitHub with the second user. The rest is all the same old git add , git commit and git push. To push from the first user, change the local user.name again and follow the same steps. Hope it helps :)


If the above steps are still not working for you, check to see if you have uploaded the RSA keys within GitHub portal. Refer to GitHub documentation:

Then, clear your ssh cached keys Reference

ssh-add -D

Then add you 2 ssh keys

ssh-add ~/.ssh/id_rsa_user1
ssh-add ~/.ssh/id_rsa_user2

Then type in your terminal:

ssh -T [email protected]<SECOND_ACCOUNT_USERNAME_HERE>

You should see the following output:

Hi <SECOND_USERNAME>! You've successfully authenticated, but GitHub does not provide shell access.

Then, assign the correct remote to your local repository. Make sure you put the same username as the one you gave in your .ssh/config file next to Host. In the following case [email protected]<SECOND_ACCOUNT_USERNAME_HERE>.

git remote rm origin
git remote add origin [email protected]<SECOND_ACCOUNT_USERNAME_HERE>:/your_username/your_repository.git

ImportError: No module named google.protobuf

I got the same error message as in the title, but in my case import google was working and import google.protobuf wasn't (on python3.5, ubuntu 16.04).

It turned out that I've installed python3-google-apputils package (using apt) and it was installed to '/usr/lib/python3/dist-packages/google/apputils/', while protobuf (which was installed using pip) was in "/usr/lib/python3.5/dist-packages/google/protobuf/" - and it was a "google" namespace collapse.

Uninstalling google-apputils (from apt, and reinstalling it using pip) solved the problem.

sudo apt remove python3-google-apputils
sudo pip3 install google-apputils

How do I get an OAuth 2.0 authentication token in C#

I used ADAL.NET/ Microsoft Identity Platform to achieve this. The advantage of using it was that we get a nice wrapper around the code to acquire AccessToken and we get additional features like Token Cache out-of-the-box. From the documentation:

Why use ADAL.NET ?

ADAL.NET V3 (Active Directory Authentication Library for .NET) enables developers of .NET applications to acquire tokens in order to call secured Web APIs. These Web APIs can be the Microsoft Graph, or 3rd party Web APIs.

Here is the code snippet:

    // Import Nuget package: Microsoft.Identity.Client
    public class AuthenticationService
    {
         private readonly List<string> _scopes;
         private readonly IConfidentialClientApplication _app;

        public AuthenticationService(AuthenticationConfiguration authentication)
        {

             _app = ConfidentialClientApplicationBuilder
                         .Create(authentication.ClientId)
                         .WithClientSecret(authentication.ClientSecret)
                         .WithAuthority(authentication.Authority)
                         .Build();

           _scopes = new List<string> {$"{authentication.Audience}/.default"};
       }

       public async Task<string> GetAccessToken()
       {
           var authenticationResult = await _app.AcquireTokenForClient(_scopes) 
                                                .ExecuteAsync();
           return authenticationResult.AccessToken;
       }
   }

Spring Boot - Loading Initial Data

You're almost there!

@Component
public class DataLoader implements CommandLineRunner {

    private UserRepository userRepository;

    public DataLoader(UserRepository userRepository) {
        this.userRepository = userRepository;
    }

    @Override
    public void run(String... args) throws Exception {
         LoadUsers()
    }

    private void LoadUsers() {
        userRepository.save(new User("lala", "lala", "lala"));
    }
}

Could not load file or assembly 'CrystalDecisions.ReportAppServer.CommLayer, Version=13.0.2000.0

If you already have the DLL copied to your project and the Copy Local flag is in true, the solution should be just rebuild the project. That will copy the DLL to the bin folder.

How to copy folders to docker image from Dockerfile?

Replace the * with a /

So instead of

COPY * <destination>

use

COPY / <destination>

How to configure Spring Security to allow Swagger URL to be accessed without authentication

I had the same problem using Spring Boot 2.0.0.M7 + Spring Security + Springfox 2.8.0. And I solved the problem using the following security configuration that allows public access to Swagger UI resources.

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true, securedEnabled = true)
public class SecurityConfiguration extends WebSecurityConfigurerAdapter {

    private static final String[] AUTH_WHITELIST = {
            // -- Swagger UI v2
            "/v2/api-docs",
            "/swagger-resources",
            "/swagger-resources/**",
            "/configuration/ui",
            "/configuration/security",
            "/swagger-ui.html",
            "/webjars/**",
            // -- Swagger UI v3 (OpenAPI)
            "/v3/api-docs/**",
            "/swagger-ui/**"
            // other public endpoints of your API may be appended to this array
    };


    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.
                // ... here goes your custom security configuration
                authorizeRequests().
                antMatchers(AUTH_WHITELIST).permitAll().  // whitelist Swagger UI resources
                // ... here goes your custom security configuration
                antMatchers("/**").authenticated();  // require authentication for any endpoint that's not whitelisted
    }

}

JPA Hibernate Persistence exception [PersistenceUnit: default] Unable to build Hibernate SessionFactory

The issue is that you are not able to get a connection to MYSQL database and hence it is throwing an error saying that cannot build a session factory.

Please see the error below:

 Caused by: java.sql.SQLException: Access denied for user ''@'localhost' (using password: NO) 

which points to username not getting populated.

Please recheck system properties

dataSource.setUsername(System.getProperty("root"));

some packages seems to be missing as well pointing to a dependency issue:

package org.gjt.mm.mysql does not exist

Please run a mvn dependency:tree command to check for dependencies

How to write to a CSV line by line?

What about this:

with open("your_csv_file.csv", "w") as f:
    f.write("\n".join(text))

str.join() Return a string which is the concatenation of the strings in iterable. The separator between elements is the string providing this method.

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'demoRestController'

Your DemoApplication class is in the com.ag.digital.demo.boot package and your LoginBean class is in the com.ag.digital.demo.bean package. By default components (classes annotated with @Component) are found if they are in the same package or a sub-package of your main application class DemoApplication. This means that LoginBean isn't being found so dependency injection fails.

There are a couple of ways to solve your problem:

  1. Move LoginBean into com.ag.digital.demo.boot or a sub-package.
  2. Configure the packages that are scanned for components using the scanBasePackages attribute of @SpringBootApplication that should be on DemoApplication.

A few of other things that aren't causing a problem, but are not quite right with the code you've posted:

  • @Service is a specialisation of @Component so you don't need both on LoginBean
  • Similarly, @RestController is a specialisation of @Component so you don't need both on DemoRestController
  • DemoRestController is an unusual place for @EnableAutoConfiguration. That annotation is typically found on your main application class (DemoApplication) either directly or via @SpringBootApplication which is a combination of @ComponentScan, @Configuration, and @EnableAutoConfiguration.

Android Studio - Failed to apply plugin [id 'com.android.application']

Feb 25th 2021:

For me, after over 8 hours of trials and errors, it was the re-ordering of the repositories sources in the project-level build.gradle file that solved the issue for me. So, instead of:

buildscript {
  ...
  repositories {
        google()
        mavenCentral()
        maven { url "https://plugins.gradle.org/m2/" }
  }
  ...
}

I moved google() to the bottom:

buildscript {
  ...
  repositories {
        mavenCentral()
        maven { url "https://plugins.gradle.org/m2/" }
        google()
  }
  ...
}

Of course, be sure to update the gradle android plugin and the matching gradle-wrapper distribution versions too.

How to configure CORS in a Spring Boot + Spring Security application?

Spring Security can now leverage Spring MVC CORS support described in this blog post I wrote.

To make it work, you need to explicitly enable CORS support at Spring Security level as following, otherwise CORS enabled requests may be blocked by Spring Security before reaching Spring MVC.

If you are using controller level @CrossOrigin annotations, you just have to enable Spring Security CORS support and it will leverage Spring MVC configuration:

@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.cors().and()...
    }
}

If you prefer using CORS global configuration, you can declare a CorsConfigurationSource bean as following:

@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {

    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.cors().and()...
    }

    @Bean
    CorsConfigurationSource corsConfigurationSource() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", new CorsConfiguration().applyPermitDefaultValues());
        return source;
    }
}

This approach supersedes the filter-based approach previously recommended.

You can find more details in the dedicated CORS section of Spring Security documentation.

How to get response from S3 getObject in Node.js?

At first glance it doesn't look like you are doing anything wrong but you don't show all your code. The following worked for me when I was first checking out S3 and Node:

var AWS = require('aws-sdk');

if (typeof process.env.API_KEY == 'undefined') {
    var config = require('./config.json');
    for (var key in config) {
        if (config.hasOwnProperty(key)) process.env[key] = config[key];
    }
}

var s3 = new AWS.S3({accessKeyId: process.env.AWS_ID, secretAccessKey:process.env.AWS_KEY});
var objectPath = process.env.AWS_S3_FOLDER +'/test.xml';
s3.putObject({
    Bucket: process.env.AWS_S3_BUCKET, 
    Key: objectPath,
    Body: "<rss><data>hello Fred</data></rss>",
    ACL:'public-read'
}, function(err, data){
    if (err) console.log(err, err.stack); // an error occurred
    else {
        console.log(data);           // successful response
        s3.getObject({
            Bucket: process.env.AWS_S3_BUCKET, 
            Key: objectPath
        }, function(err, data){
            console.log(data.Body.toString());
        });
    }
});

Failed to load ApplicationContext (with annotation)

Your test requires a ServletContext: add @WebIntegrationTest

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = AppConfig.class, loader = AnnotationConfigContextLoader.class)
@WebIntegrationTest
public class UserServiceImplIT

...or look here for other options: https://docs.spring.io/spring-boot/docs/current/reference/html/boot-features-testing.html

UPDATE In Spring Boot 1.4.x and above @WebIntegrationTest is no longer preferred. @SpringBootTest or @WebMvcTest

What should I use to open a url instead of urlopen in urllib3

The new urllib3 library has a nice documentation here
In order to get your desired result you shuld follow that:

Import urllib3
from bs4 import BeautifulSoup

url = 'http://www.thefamouspeople.com/singers.php'

http = urllib3.PoolManager()
response = http.request('GET', url)
soup = BeautifulSoup(response.data.decode('utf-8'))

The "decode utf-8" part is optional. It worked without it when i tried, but i posted the option anyway.
Source: User Guide

disabling spring security in spring boot app

I think you must also remove security auto config from your @SpringBootApplication annotated class:

@EnableAutoConfiguration(exclude = {
    org.springframework.boot.autoconfigure.security.SecurityAutoConfiguration.class,
    org.springframework.boot.actuate.autoconfigure.ManagementSecurityAutoConfiguration.class})

Method List in Visual Studio Code

In 2020 version of VSCode
Cmd+P

  • # - Find symbol across files
  • @ - Find symbol within file
  • @: - Group symbols within a file

Symbols in a file VS Code v1.44.0

Could not autowire field:RestTemplate in Spring boot application

Since RestTemplate instances often need to be customized before being used, Spring Boot does not provide any single auto-configured RestTemplate bean.

RestTemplateBuilder offers proper way to configure and instantiate the rest template bean, for example for basic auth or interceptors.

@Bean
public RestTemplate restTemplate(RestTemplateBuilder builder) {
    return builder
                .basicAuthorization("user", "name") // Optional Basic auth example
                .interceptors(new MyCustomInterceptor()) // Optional Custom interceptors, etc..
                .build();
}

Custom header to HttpClient request

Here is an answer based on that by Anubis (which is a better approach as it doesn't modify the headers for every request) but which is more equivalent to the code in the original question:

using Newtonsoft.Json;
...

var client = new HttpClient();
var httpRequestMessage = new HttpRequestMessage
    {
        Method = HttpMethod.Post,
        RequestUri = new Uri("https://api.clickatell.com/rest/message"),
        Headers = { 
            { HttpRequestHeader.Authorization.ToString(), "Bearer xxxxxxxxxxxxxxxxxxx" },
            { HttpRequestHeader.Accept.ToString(), "application/json" },
            { "X-Version", "1" }
        },
        Content = new StringContent(JsonConvert.SerializeObject(svm))
    };

var response = client.SendAsync(httpRequestMessage).Result;

SSL: CERTIFICATE_VERIFY_FAILED with Python3

Go to the folder where Python is installed, e.g., in my case (Mac OS) it is installed in the Applications folder with the folder name 'Python 3.6'. Now double click on 'Install Certificates.command'. You will no longer face this error.

For those not running a mac, or having a different setup and can't find this file, the file merely runs:

pip install --upgrade certifi

Hope that helps someone :)

How, in general, does Node.js handle 10,000 concurrent requests?

Adding to slebetman answer: When you say Node.JS can handle 10,000 concurrent requests they are essentially non-blocking requests i.e. these requests are majorly pertaining to database query.

Internally, event loop of Node.JS is handling a thread pool, where each thread handles a non-blocking request and event loop continues to listen to more request after delegating work to one of the thread of the thread pool. When one of the thread completes the work, it send a signal to the event loop that it has finished aka callback. Event loop then process this callback and send the response back.

As you are new to NodeJS, do read more about nextTick to understand how event loop works internally. Read blogs on http://javascriptissexy.com, they were really helpful for me when I started with JavaScript/NodeJS.

Spring Boot REST API - request timeout?

You can configure the Async thread executor for your Springboot REST services. The setKeepAliveSeconds() should consider the execution time for the requests chain. Set the ThreadPoolExecutor's keep-alive seconds. Default is 60. This setting can be modified at runtime, for example through JMX.

@Bean(name="asyncExec")
public Executor asyncExecutor()
{
    ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
    executor.setCorePoolSize(3);
    executor.setMaxPoolSize(3);
    executor.setQueueCapacity(10);
    executor.setThreadNamePrefix("AsynchThread-");
    executor.setAllowCoreThreadTimeOut(true);
    executor.setKeepAliveSeconds(10);
    executor.initialize();

    return executor;
}

Then you can define your REST endpoint as follows

@Async("asyncExec")
@PostMapping("/delayedService")
public CompletableFuture<String> doDelay()
{ 
    String response = service.callDelayedService();
    return CompletableFuture.completedFuture(response);
}

How can I resolve the error "The security token included in the request is invalid" when running aws iam upload-server-certificate?

  1. Click on your username in the top nav, My Security Credentials
  2. Click on Access Key Tab, Create New, copy the key and secret.
  3. From the terminal run $ aws configure and use the new key and secret.
  4. Run the command again:

    serverless invoke local --function create --path mocks/create-event.json
    

npm - "Can't find Python executable "python", you can set the PYTHON env variable."

You are running the Command Prompt as an admin. You have only defined PYTHON for your user. You need to define it in the bottom "System variables" section.

Also, you should only point the variable to the folder, not directly to the executable.

Spring Boot @autowired does not work, classes in different package

Try annotating your Configuration Class(es) with the @ComponentScan("com.esri.birthdays") annotation. Generally spoken: If you have sub-packages in your project, then you have to scan for your relevant classes on project-root. I guess for your case it'll be "com.esri.birthdays". You won't need the ComponentScan, if you have no sub-packaging in your project.

TypeError: a bytes-like object is required, not 'str' in python and CSV

just change wb to w

outfile=open('./immates.csv','wb')

to

outfile=open('./immates.csv','w')

How to get bean using application context in spring boot

Even after adding @Autowire if your class is not a RestController or Configuration Class, the applicationContext object was coming as null. Tried Creating new class with below and it is working fine:

@Component
public class SpringContext implements ApplicationContextAware{

   private static ApplicationContext applicationContext;

   @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws 
     BeansException {
    this.applicationContext=applicationContext;
   }
 }

you can then implement a getter method in the same class as per your need to get the bean. Like:

    applicationContext.getBean(String serviceName,Interface.Class)

How to restart kubernetes nodes?

If a node is so unhealthy that the master can't get status from it -- Kubernetes may not be able to restart the node. And if health checks aren't working, what hope do you have of accessing the node by SSH?

In this case, you may have to hard-reboot -- or, if your hardware is in the cloud, let your provider do it.

For example, the AWS EC2 Dashboard allows you to right-click an instance to pull up an "Instance State" menu -- from which you can reboot/terminate an unresponsive node.

Before doing this, you might choose to kubectl cordon node for good measure. And you may find kubectl delete node to be an important part of the process for getting things back to normal -- if the node doesn't automatically rejoin the cluster after a reboot.


Why would a node become unresponsive? Probably some resource has been exhausted in a way that prevents the host operating system from handling new requests in a timely manner. This could be disk, or network -- but the more insidious case is out-of-memory (OOM), which Linux handles poorly.

To help Kubernetes manage node memory safely, it's a good idea to do both of the following:

  • Reserve some memory for the system.
  • Be very careful with (avoid) opportunistic memory specifications for your pods. In other words, don't allow different values of requests and limits for memory.

The idea here is to avoid the complications associated with memory overcommit, because memory is incompressible, and both Linux and Kubernetes' OOM killers may not trigger before the node has already become unhealthy and unreachable.

Best HTTP Authorization header type for JWT

The best HTTP header for your client to send an access token (JWT or any other token) is the Authorization header with the Bearer authentication scheme.

This scheme is described by the RFC6750.

Example:

GET /resource HTTP/1.1
Host: server.example.com
Authorization: Bearer eyJhbGciOiJIUzI1NiIXVCJ9TJV...r7E20RMHrHDcEfxjoYZgeFONFh7HgQ

If you need stronger security protection, you may also consider the following IETF draft: https://tools.ietf.org/html/draft-ietf-oauth-pop-architecture. This draft seems to be a good alternative to the (abandoned?) https://tools.ietf.org/html/draft-ietf-oauth-v2-http-mac.

Note that even if this RFC and the above specifications are related to the OAuth2 Framework protocol, they can be used in any other contexts that require a token exchange between a client and a server.

Unlike the custom JWT scheme you mention in your question, the Bearer one is registered at the IANA.

Concerning the Basic and Digest authentication schemes, they are dedicated to authentication using a username and a secret (see RFC7616 and RFC7617) so not applicable in that context.

Spring boot - configure EntityManager

With Spring Boot its not necessary to have any config file like persistence.xml. You can configure with annotations Just configure your DB config for JPA in the

application.properties

spring.datasource.driverClassName=oracle.jdbc.driver.OracleDriver
spring.datasource.url=jdbc:oracle:thin:@DB...
spring.datasource.username=username
spring.datasource.password=pass

spring.jpa.database-platform=org.hibernate.dialect....
spring.jpa.show-sql=true

Then you can use CrudRepository provided by Spring where you have standard CRUD transaction methods. There you can also implement your own SQL's like JPQL.

@Transactional
public interface ObjectRepository extends CrudRepository<Object, Long> {
...
}

And if you still need to use the Entity Manager you can create another class.

public class ObjectRepositoryImpl implements ObjectCustomMethods{

    @PersistenceContext
    private EntityManager em;

}

This should be in your pom.xml

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.2.5.RELEASE</version>
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>4.3.11.Final</version>
    </dependency>
</dependencies>

Spring jUnit Testing properties file

Firstly, application.properties in the @PropertySource should read application-test.properties if that's what the file is named (matching these things up matters):

@PropertySource("classpath:application-test.properties ")

That file should be under your /src/test/resources classpath (at the root).

I don't understand why you'd specify a dependency hard coded to a file called application-test.properties. Is that component only to be used in the test environment?

The normal thing to do is to have property files with the same name on different classpaths. You load one or the other depending on whether you are running your tests or not.

In a typically laid out application, you'd have:

src/test/resources/application.properties

and

src/main/resources/application.properties

And then inject it like this:

@PropertySource("classpath:application.properties")

The even better thing to do would be to expose that property file as a bean in your spring context and then inject that bean into any component that needs it. This way your code is not littered with references to application.properties and you can use anything you want as a source of properties. Here's an example: how to read properties file in spring project?

HikariCP - connection is not available

From stack trace:

HikariPool: Timeout failure pool HikariPool-0 stats (total=20, active=20, idle=0, waiting=0) Means pool reached maximum connections limit set in configuration.

The next line: HikariPool-0 - Connection is not available, request timed out after 30000ms. Means pool waited 30000ms for free connection but your application not returned any connection meanwhile.

Mostly it is connection leak (connection is not closed after borrowing from pool), set leakDetectionThreshold to the maximum value that you expect SQL query would take to execute.

otherwise, your maximum connections 'at a time' requirement is higher than 20 !

Ubuntu: OpenJDK 8 - Unable to locate package

UPDATE: installation without root privileges below


I advise you to not install packages manually on ubuntu system if there is already a (semi-official) repository able to solve your problem. Further, use Oracle JDK for development, just to avoid (very sporadic) compatibility issues (i've tried many years ago, it's surely better now).

Add the webupd8 repo to your system:

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update

Install your preferred version of jdk (versions from java-6 to java-9 available):

sudo apt-get install oracle-java8-installer

You can also install multiple version of jdk, mixing openjdk and oracle versions. Then you can use the command update-java-alternatives to switch between installed version:

# list available jdk
update-java-alternatives --list

# use jdk7
sudo update-java-alternatives --set java-7-oracle

# use jdk8
sudo update-java-alternatives --set java-8-oracle

Requirements

If you get add-apt-repository: command not found be sure to have software-properties-common installed:

sudo apt-get install software-properties-common

If you're using an older version Ubuntu:

sudo apt-get install python-software-properties

JDK installation without root privileges

If you haven't administrator rights on your target machine your simplest bet is to use sdkman to install the zulu certified openjdk:

curl -s "https://get.sdkman.io" | bash
source "$HOME/.sdkman/bin/sdkman-init.sh"
sdk install java

NOTE: sdkman allow to install also the official Oracle JDK, although it's not a the default option. View available versions with:

sdk ls java

Install the chosen version with:

sdk install java <version>

For example:

sdk install java 9.0.1-oracle

Glossary of commands

  • sudo <command> [command_arguments]: execute a command with the superuser privilege.

  • add-apt-repository <PPA_id>: Ubuntu (just like every Debian derivatives and generally speaking every Linux distribution) has a main repository of packages that handle things like package dependencies and updating. In Ubuntu is possible to extend the main repository using a PPA (Personal Package Archive) that usually contains packages not available in the system (just like oracle jdk) or updated versions of available ones (example: LibreOffice 5 in LTS is available only through this PPA).

  • apt-get [install|update|upgrade|purge|...]: it's "the" command-line package handler used to manipulate the state of every repository on the system (installing / updating / upgrading can be viewed as an alteration of the repository current state).

In our case: with the command sudo add-apt-repository ppa:webupd8team/java we inform the system that the next repository update must retrieve packages information also from webupd8 repo.

With sudo apt-get update we actually update the system repository (all this operations requires superuser privileges, so we prepend sudo to the commands).

sudo apt-get install oracle-java8-installer

  • update-java-alternatives (a specific java version of update-alternatives): in Ubuntu several packages provides the same functionality (browse the internet, compile mails, edit a text file or provides java/javac executables...). To allows the system to choose the user favourites tool given a specific task a mechanism using symlinks under /etc/alternatives/ is used. Try to update the jdk as indicated above (switch between java 7 and java 8) and view how change the output of this command:

    ls -l /etc/alternatives/java*

In our case: sudo update-java-alternatives --set java-8-oracle update symlinks under /etc/alternatives to point to java-8-oracle executables.

Extras:

  • man <command>: start using man to read a really well written and detailed help on (almost) every shell command and its options (every command i mention in this little answer has a man page, try man update-java-alternatives).

  • apt-cache search <search_key>: query the APT cache to search for a package related with the search_key provided (can be the package name or some word in package description).

  • apt-cache show <package>: provides APT information for a specific package (package version, installed or not, description).

How can I represent 'Authorization: Bearer <token>' in a Swagger Spec (swagger.json)

By using the requestInterceptor, it worked for me:

const ui = SwaggerUIBundle({
  ...
  requestInterceptor: (req) => {
    req.headers.Authorization = "Bearer " + req.headers.Authorization;
    return req;
  },
  ...
});

java.lang.IllegalStateException: Error processing condition on org.springframework.boot.autoconfigure.jdbc.JndiDataSourceAutoConfiguration

I know this is quite an old one, but I faced similar issue and resolved it in a different way. The actuator-autoconfigure pom somehow was invalid and so it was throwing IllegalStateException. I removed the actuator* dependencies from my maven repo and did a Maven update in eclipse, which then downloaded the correct/valid dependencies and resolved my issue.

How to Get JSON Array Within JSON Object?

I guess this will help you.

JSONObject jsonObj = new JSONObject(jsonStr);

JSONArray ja_data = jsonObj.getJSONArray("data");
int length = jsonObj.length();
for(int i=0; i<length; i++) {
  JSONObject jsonObj = ja_data.getJSONObject(i);
  Toast.makeText(this, jsonObj.getString("Name"), Toast.LENGTH_LONG).show();

  // getting inner array Ingredients
  JSONArray ja = jsonObj.getJSONArray("Ingredients");
  int len = ja.length();

  ArrayList<String> Ingredients_names = new ArrayList<>();
  for(int j=0; j<len; j++) {
    JSONObject json = ja.getJSONObject(j);
    Ingredients_names.add(json.getString("name"));
  }
}

toBe(true) vs toBeTruthy() vs toBeTrue()

Disclamer: This is just a wild guess

I know everybody loves an easy-to-read list:

  • toBe(<value>) - The returned value is the same as <value>
  • toBeTrue() - Checks if the returned value is true
  • toBeTruthy() - Check if the value, when cast to a boolean, will be a truthy value

    Truthy values are all values that aren't 0, '' (empty string), false, null, NaN, undefined or [] (empty array)*.

    * Notice that when you run !![], it returns true, but when you run [] == false it also returns true. It depends on how it is implemented. In other words: (!![]) === ([] == false)


On your example, toBe(true) and toBeTrue() will yield the same results.

Mapping list in Yaml to list of objects in Spring Boot

for me the fix was to add the injected class as inner class in the one annotated with @ConfigurationProperites, because I think you need @Component to inject properties.

WARNING: Exception encountered during context initialization - cancelling refresh attempt

  1. To closed ideas,
  2. To remove all folder and file C:/Users/UserName/.m2/org/*,
  3. Open ideas and update Maven project,(right click on project -> maven->update maven project)
  4. After that update the project.

Spring - No EntityManager with actual transaction available for current thread - cannot reliably process 'persist' call

Without @Transactional annotation you can achieve the same goal with finding the entity from the DB and then removing that entity you got from the DB.

CrudRepositor -> void delete(T var1);

How to find distinct rows with field in list using JPA and Spring?

I finally was able to figure out a simple solution without the @Query annotation.

List<People> findDistinctByNameNotIn(List<String> names);

Of course, I got the people object instead of only Strings. I can then do the change in java.

Using Postman to access OAuth 2.0 Google APIs

Postman will query Google API impersonating a Web Application

Generate an OAuth 2.0 token:

  1. Ensure that the Google APIs are enabled
  2. Create an OAuth 2.0 client ID

    • Go to Google Console -> API -> OAuth consent screen
      • Add getpostman.com to the Authorized domains. Click Save.
    • Go to Google Console -> API -> Credentials
      • Click 'Create credentials' -> OAuth client ID -> Web application
        • Name: 'getpostman'
        • Authorized redirect URIs: https://www.getpostman.com/oauth2/callback
    • Copy the generated Client ID and Client secret fields for later use
  3. In Postman select Authorization tab and select "OAuth 2.0" type. Click 'Get New Access Token'

    • Fill the GET NEW ACCESS TOKEN form as following
      • Token Name: 'Google OAuth getpostman'
      • Grant Type: 'Authorization Code'
      • Callback URL: https://www.getpostman.com/oauth2/callback
      • Auth URL: https://accounts.google.com/o/oauth2/auth
      • Access Token URL: https://accounts.google.com/o/oauth2/token
      • Client ID: Client ID generated in the step 2 (e.g., '123456789012-abracadabra1234546789blablabla12.apps.googleusercontent.com')
      • Client Secret: Client secret generated in the step 2 (e.g., 'ABRACADABRAus1ZMGHvq9R-L')
      • Scope: see the Google docs for the required OAuth scope (e.g., https://www.googleapis.com/auth/cloud-platform)
      • State: Empty
      • Client Authentication: "Send as Basic Auth header"
    • Click 'Request Token' and 'Use Token'
  4. Set the method, parameters, and body of your request according to the Google docs

Error resolving template "index", template might not exist or might not be accessible by any of the configured Template Resolvers

Check for the name of the

templates

folder. it should be templates not template(without s).

pip install failing with: OSError: [Errno 13] Permission denied on directory

It is due permission problem,

sudo chown -R $USER /path to your python installed directory

default it would be /usr/local/lib/python2.7/

or try,

pip install --user -r package_name

and then say, pip install -r requirements.txt this will install inside your env

dont say, sudo pip install -r requirements.txt this is will install into arbitrary python path.

Spring Boot: Cannot access REST Controller on localhost (404)

Place your springbootapplication class in root package for example if your service,controller is in springBoot.xyz package then your main class should be in springBoot package otherwise it will not scan below packages

Any way (or shortcut) to auto import the classes in IntelliJ IDEA like in Eclipse?

Can't import all at once but can use following combination:

ALT + Enter --> Show intention actions and quick-fixes.

F2 --> Next highlighted error.

How to set the title text color of UIButton?

Example in setting button title color

btnDone.setTitleColor(.black, for: .normal)

I'm getting favicon.ico error

The accepted answer didn't work for me, I had to add a value to the href attribute:

<link rel="shortcut icon" href="#" />

How do I enable logging for Spring Security?

By default Spring Security redirects user to the URL that he originally requested (/Load.do in your case) after login.

You can set always-use-default-target to true to disable this behavior:

 <security:http auto-config="true">

    <security:intercept-url pattern="/Admin**" access="hasRole('PROGRAMMER') or hasRole('ADMIN')"/>
    <security:form-login login-page="/Load.do"
        default-target-url="/Admin.do?m=loadAdminMain"
        authentication-failure-url="/Load.do?error=true"
        always-use-default-target = "true"
        username-parameter="j_username"
        password-parameter="j_password"
        login-processing-url="/j_spring_security_check"/>
    <security:csrf/><!-- enable Cross Site Request Forgery protection -->
</security:http>

Spring MVC 4: "application/json" Content Type is not being set correctly

When I upgraded to Spring 4 I needed to update the jackson dependencies as follows:

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.5.1</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.5.1</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.5.1</version>
    </dependency>        

Correct way to set Bearer token with CURL

Guzzle example:

use GuzzleHttp\Client;
use GuzzleHttp\RequestOptions;

$token = 'your_token';

$httpClient = new Client();

$response = $httpClient->get(
    'https://httpbin.org/bearer',
    [
        RequestOptions::HEADERS => [
            'Accept' => 'application/json',
            'Authorization' => 'Bearer ' . $token,
        ]
    ]
);

print_r($response->getBody()->getContents());

See https://github.com/andriichuk/php-curl-cookbook#bearer-auth

Using an authorization header with Fetch in React Native

I had this identical problem, I was using django-rest-knox for authentication tokens. It turns out that nothing was wrong with my fetch method which looked like this:

...
    let headers = {"Content-Type": "application/json"};
    if (token) {
      headers["Authorization"] = `Token ${token}`;
    }
    return fetch("/api/instruments/", {headers,})
      .then(res => {
...

I was running apache.

What solved this problem for me was changing WSGIPassAuthorization to 'On' in wsgi.conf.

I had a Django app deployed on AWS EC2, and I used Elastic Beanstalk to manage my application, so in the django.config, I did this:

container_commands:
  01wsgipass:
    command: 'echo "WSGIPassAuthorization On" >> ../wsgi.conf'

How do you format code in Visual Studio Code (VSCode)

Just install Visual Studio Keymap (Visual Studio Keymap for Visual Studio Code) by Microsoft. Problem Solved. :p

Making an API call in Python with an API that requires a bearer token

It just means it expects that as a key in your header data

import requests
endpoint = ".../api/ip"
data = {"ip": "1.1.2.3"}
headers = {"Authorization": "Bearer MYREALLYLONGTOKENIGOT"}

print(requests.post(endpoint, data=data, headers=headers).json())

How to get local server host and port in Spring Boot?

An easy workaround, at least to get the running port, is to add the parameter javax.servlet.HttpServletRequest in the signature of one of the controller's methods. Once you have the HttpServletRequest instance is straightforward to get the baseUrl with this: request.getRequestURL().toString()

Have a look at this code:

@PostMapping(value = "/registration" , produces = "application/json")
public StringResponse register(@RequestBody RequestUserDTO userDTO, 
    HttpServletRequest request) {
request.getRequestURL().toString();
//value: http://localhost:8080/registration
------
return "";
}

UnsatisfiedDependencyException: Error creating bean with name 'entityManagerFactory'

Well, you're getting a java.lang.NoClassDefFoundError. In your pom.xml, hibernate-core version is 3.3.2.GA and declared after hibernate-entitymanager, so it prevails. You can remove that dependency, since will be inherited version 3.6.7.Final from hibernate-entitymanager.

You're using spring-boot as parent, so no need to declare version of some dependencies, since they are managed by spring-boot.

Also, hibernate-commons-annotations is inherited from hibernate-entitymanager and hibernate-annotations is an old version of hibernate-commons-annotations, you can remove both.

Finally, your pom.xml can look like this:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.elsys.internetprogramming.trafficspy.server</groupId>
    <artifactId>TrafficSpyService</artifactId>
    <version>0.1.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.2.3.RELEASE</version>
    </parent>

    <dependencies>
        <!-- Spring -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-cloud-connectors</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>

        <dependency>
            <groupId>org.eclipse.persistence</groupId>
            <artifactId>javax.persistence</artifactId>
            <version>2.0.0</version>
        </dependency>

        <!-- Hibernate -->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-entitymanager</artifactId>
        </dependency>
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
        </dependency>

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
        </dependency>
        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
        </dependency>
        <dependency>
            <groupId>commons-pool</groupId>
            <artifactId>commons-pool</artifactId>
        </dependency>

        <!-- MySQL -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>

    <properties>
        <java.version>1.7</java.version>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

    <repositories>
        <repository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </repository>

        <repository>
            <id>codehaus</id>
            <url>http://repository.codehaus.org/org/codehaus</url>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </pluginRepository>
    </pluginRepositories>

</project>

Let me know if you have a problem.

Getting "error": "unsupported_grant_type" when trying to get a JWT by calling an OWIN OAuth secured Web Api via Postman

Old Question, but for angular 6, this needs to be done when you are using HttpClient I am exposing token data publicly here but it would be good if accessed via read-only properties.

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable, of } from 'rxjs';
import { delay, tap } from 'rxjs/operators';
import { Router } from '@angular/router';


@Injectable()
export class AuthService {
    isLoggedIn: boolean = false;
    url = "token";

    tokenData = {};
    username = "";
    AccessToken = "";

    constructor(private http: HttpClient, private router: Router) { }

    login(username: string, password: string): Observable<object> {
        let model = "username=" + username + "&password=" + password + "&grant_type=" + "password";

        return this.http.post(this.url, model).pipe(
            tap(
                data => {
                    console.log('Log In succesful')
                    //console.log(response);
                    this.isLoggedIn = true;
                    this.tokenData = data;
                    this.username = data["username"];
                    this.AccessToken = data["access_token"];
                    console.log(this.tokenData);
                    return true;

                },
                error => {
                    console.log(error);
                    return false;

                }
            )
        );
    }
}

Required request body content is missing: org.springframework.web.method.HandlerMethod$HandlerMethodParameter

You shouldn't send a request body with an HTTP GET request. You should modify addDepartment() so that it only supports POST, and POST your JSON to that endpoint. If you want to GET information about a department, you should create a separate controller method that does that (and does not require a request body).

Also, double-check your endpoint definitions since you have misspelled "reimbursement" in the $.ajax call.

Can't Autowire @Repository annotated interface in Spring Boot

Make sure the @Service or @Component that is trying to auto-wire the repository isn't in the same directory as your SpringApplication.class. Make sure it's in a subfolder like service/.

InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately

If you are not able to upgrade your Python version to 2.7.9, and want to suppress warnings,

you can downgrade your 'requests' version to 2.5.3:

pip install requests==2.5.3

Bugfix disclosure / Warning introduced in 2.6.0

changing kafka retention period during runtime

The correct config key is retention.ms

$ bin/kafka-topics.sh --zookeeper zk.prod.yoursite.com --alter --topic as-access --config retention.ms=86400000
Updated config for topic "my-topic".

Convert a object into JSON in REST service by Spring MVC

Another simple solution is to add jackson-databind dependency in POM.

    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.8.1</version>
    </dependency>

Keep Rest of the code as it is.

Cannot find java. Please use the --jdkhome switch

In my case, I had installed *ahem* OpenJDK, but the bin folder was full of symlinks to the bundled JRE and the actual JDK was nowhere to be found.

When I see a directory structure with bin and jre subdirectories I expect this to be the JDK installation, because JRE installations on Windows looked different. But in this case it was the JRE installation as found out by apt search. After installing openjdk-8-jre the simlinks were replaced and the directory structure otherwise stayed the same.

Netbeans 8.0.2 The module has not been deployed

I had the same error here but with glassfish server. Maybe it can help. I needed to configure the glassfish-web.xml file with the content inside the <resources> from glassfish-resources.xml. As I got another error I could find this annotation in the server log:

Caused by: java.lang.RuntimeException: Error in parsing WEB-INF/glassfish-web.xml for archive [file:/C:/Users/Win/Documents/NetBeansProjects/svad/build/web/]: The xml element should be [glassfish-web-app] rather than [resources]

All I did then was to change the <resources> tag and apply <glassfish-web-app> in the glassfish-web.xml file.

Spring boot - Not a managed type

Try adding All the following, In my application it is working fine with tomcat

 @EnableJpaRepositories("my.package.base.*")
 @ComponentScan(basePackages = { "my.package.base.*" })
 @EntityScan("my.package.base.*")   

I am using spring boot, and when i am using embedded tomcat it was working fine with out @EntityScan("my.package.base.*") but when I tried to deploy the app to an external tomcat I got not a managed type error for my entity.

@Autowired - No qualifying bean of type found for dependency at least 1 bean

Just add below annotation with qualifier name of service in service Implementation class:

@Service("employeeService")
@Transactional
public class EmployeeServiceImpl implements EmployeeService{
}

"Could not find acceptable representation" using spring-boot-starter-web

In my case I happened to be using lombok and apparently there are conflicts with the get and set

How to change default Anaconda python environment

Load your "base" environment -- as OP's py34 -- when you load your terminal/shell.

If you use Bash, put the line:

conda activate py34

in your .bash_profile (or .bashrc):

$ echo 'conda activate py34' >> ~/.bash_profile

Every time you run a new terminal, conda environment py34 will be loaded.

Open web in new tab Selenium + Python

You can achieve the opening/closing of a tab by the combination of keys COMMAND + T or COMMAND + W (OSX). On other OSs you can use CONTROL + T / CONTROL + W.

In selenium you can emulate such behavior. You will need to create one webdriver and as many tabs as the tests you need.

Here it is the code.

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

driver = webdriver.Firefox()
driver.get("http://www.google.com/")

#open tab
driver.find_element_by_tag_name('body').send_keys(Keys.COMMAND + 't') 
# You can use (Keys.CONTROL + 't') on other OSs

# Load a page 
driver.get('http://stackoverflow.com/')
# Make the tests...

# close the tab
# (Keys.CONTROL + 'w') on other OSs.
driver.find_element_by_tag_name('body').send_keys(Keys.COMMAND + 'w') 


driver.close()

How to determine programmatically the current active profile using Spring boot

It doesn't matter is your app Boot or just raw Spring. There is just enough to inject org.springframework.core.env.Environment to your bean.

@Autowired
private Environment environment;
....

this.environment.getActiveProfiles();

How to customise the Jackson JSON mapper implicitly used by Spring Boot?

A lot of things can configured in applicationproperties. Unfortunately this feature only in Version 1.3, but you can add in a Config-Class

@Autowired(required = true)
public void configureJackson(ObjectMapper jackson2ObjectMapper) {
    jackson2ObjectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
}

[UPDATE: You must work on the ObjectMapper because the build()-method is called before the config is runs.]

Spring Could not Resolve placeholder

You are not reading the properties file correctly. The propertySource should pass the parameter as: file:appclient.properties or classpath:appclient.properties. Change the annotation to:

@PropertySource(value={"classpath:appclient.properties"})

However I don't know what your PropertiesConfig file contains, as you're importing that also. Ideally the @PropertySource annotation should have been kept there.

Spring Boot - Error creating bean with name 'dataSource' defined in class path resource

In my case this was happening because org.springframework.boot.autoconfigure.orm.jpa.JpaBaseConfiguration.dataSource is an autowired field without a Qualifier and I am using multiple datasources with qualified names. I solved this problem by using @Primary arbitrarily on one of my dataSource bean configurations like so

@Primary
@Bean(name="oneOfManyDataSources")
public DataSource dataSource() { ... }

I suppose they want you to implement AbstractRoutingDataSource, and then that auto configuration will just work because no qualifier is needed, you just have a single data source that allows your beans to resolve to the appropriate DataSource as needed. Then you don't need the @Primary or @Qualifier annotations at all, because you just have a single DataSource.

In any case, my solution worked because my beans specify DataSource by qualifier, and the JPA auto config stuff is happy because it has a single primary DataSource. I am by no means recommending this as the "right" way to do things, but in my case it solved the problem quickly and did not deter the behavior of my application in any noticeable manner. Will hopefully one day get around to implementing the AbstractRoutingDataSource and refactoring all the beans that need a specific DataSource and then perhaps that will be a neater solution.

How to autowire RestTemplate using annotations

If you're using Spring Boot 1.4.0 or later as the basis of your annotation-driven, Spring doesn't provides a single auto-configured RestTemplate bean. From their documentation:

https://docs.spring.io/spring-boot/docs/1.4.0.RELEASE/reference/html/boot-features-restclient.html

If you need to call remote REST services from your application, you can use Spring Framework’s RestTemplate class. Since RestTemplate instances often need to be customized before being used, Spring Boot does not provide any single auto-configured RestTemplate bean. It does, however, auto-configure a RestTemplateBuilder which can be used to create RestTemplate instances when needed. The auto-configured RestTemplateBuilder will ensure that sensible HttpMessageConverters are applied to RestTemplate instances.

How to use Spring Boot with MySQL database and JPA?

When moving classes into specific packages like repository, controller, domain just the generic @SpringBootApplication is not enough.

You will have to specify the base package for component scan

@ComponentScan("base_package")

For JPA

@EnableJpaRepositories(basePackages = "repository")

is also needed, so spring data will know where to look into for repository interfaces.

Can not deserialize instance of java.lang.String out of START_ARRAY token

The error is:

Can not deserialize instance of java.lang.String out of START_ARRAY token at [Source: line: 1, column: 1095] (through reference chain: JsonGen["platforms"])

In JSON, platforms look like this:

"platforms": [
    {
        "platform": "iphone"
    },
    {
        "platform": "ipad"
    },
    {
        "platform": "android_phone"
    },
    {
        "platform": "android_tablet"
    }
]

So try change your pojo to something like this:

private List platforms;

public List getPlatforms(){
    return this.platforms;
}

public void setPlatforms(List platforms){
    this.platforms = platforms;
}

EDIT: you will need change mobile_networks too. Will look like this:

private List mobile_networks;

public List getMobile_networks() {
    return mobile_networks;
}

public void setMobile_networks(List mobile_networks) {
    this.mobile_networks = mobile_networks;
}

Spring Boot Multiple Datasource

Using two datasources you need their own transaction managers.

@Configuration
public class MySqlDBConfig {
    @Bean
    @Primary
    @ConfigurationProperties(prefix="datasource.test.mysql")
    public DataSource mysqlDataSource(){
         return DataSourceBuilder
                 .create()
                 .build();
    }

    @Bean("mysqlTx")
    public DataSourceTransactionManager mysqlTx() {
        return new DataSourceTransactionManager(mysqlDataSource());
    }

    // same for another DS
}

And then use it accordingly within @Transaction

@Transactional("mysqlTx")
@Repository
public interface UserMysqlDao extends CrudRepository<UserMysql, Integer>{
    public UserMysql findByName(String name);
}

UnicodeEncodeError: 'charmap' codec can't encode characters

if you are using windows try to pass encoding='latin1', encoding='iso-8859-1' or encoding='cp1252' example:

csv_data = pd.read_csv(csvpath,encoding='iso-8859-1')
print(print(soup.encode('iso-8859-1')))

Multipart File Upload Using Spring Rest Template + Spring Web MVC

Here are my working example

@RequestMapping(value = "/api/v1/files/upload", method =RequestMethod.POST)
public ResponseEntity<?> upload(@RequestParam("files") MultipartFile[] files) {
    LinkedMultiValueMap<String, Object> map = new LinkedMultiValueMap<>();
    List<String> tempFileNames = new ArrayList<>();
    String tempFileName;
    FileOutputStream fo;

    try {
        for (MultipartFile file : files) {
            tempFileName = "/tmp/" + file.getOriginalFilename();
            tempFileNames.add(tempFileName);
            fo = new FileOutputStream(tempFileName);
            fo.write(file.getBytes());
            fo.close();
            map.add("files", new FileSystemResource(tempFileName));
        }

        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.MULTIPART_FORM_DATA);

        HttpEntity<LinkedMultiValueMap<String, Object>> requestEntity = new HttpEntity<>(map, headers);
        String response = restTemplate.postForObject(uploadFilesUrl, requestEntity, String.class);

    } catch (IOException e) {
        e.printStackTrace();
    }

    for (String fileName : tempFileNames) {
        File f = new File(fileName);
        f.delete();
    }
    return new ResponseEntity<Object>(HttpStatus.OK);
}

intellij incorrectly saying no beans of type found for autowired repository

Add Spring annotation @Repository over the repository class.

I know it should work without this annotation. But if you add this, IntelliJ will not show error.

@Repository
public interface YourRepository ...
...

If you use Spring Data with extending Repository class it will be conflict pagkages. Then you must indicate explicity pagkages.

import org.springframework.data.repository.Repository;
...

@org.springframework.stereotype.Repository
public interface YourRepository extends Repository<YourClass, Long> {
    ...
}

And next you can autowired your repository without errors.

@Autowired
YourRepository yourRepository;

It probably is not a good solution (I guess you are trying to register repositorium twice). But work for me and don't show errors.

Maybe in the new version of IntelliJ can be fixed: https://youtrack.jetbrains.com/issue/IDEA-137023

Show DataFrame as table in iPython Notebook

In order to show the DataFrame in Jupyter Notebook just type:

   display(Name_of_the_DataFrame)

for example:

  display(df)

Spring AMQP + RabbitMQ 3.3.5 ACCESS_REFUSED - Login was refused using authentication mechanism PLAIN

To allow guest access remotely, write this

[{rabbit, [{loopback_users, []}]}].

to here

c:\Users\[your user name]\AppData\Roaming\RabbitMQ\rabbitmq.config

then restart the rabbitmq windows service (Source https://www.rabbitmq.com/access-control.html)

How to filter an array of objects based on values in an inner array with jq?

Here is another solution which uses any/2

map(select(any(.Names[]; contains("data"))|not)|.Id)[]

with the sample data and the -r option it produces

cb94e7a42732b598ad18a8f27454a886c1aa8bbba6167646d8f064cd86191e2b
a4b7e6f5752d8dcb906a5901f7ab82e403b9dff4eaaeebea767a04bac4aada19

org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set

In spring boot for jpa java config you need to extend JpaBaseConfiguration and implement it's abstract methods.

@Configuration
public class JpaConfig extends JpaBaseConfiguration {

    @Override
    protected AbstractJpaVendorAdapter createJpaVendorAdapter() {
        final HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        return vendorAdapter;
    }

    @Override
    protected Map<String, Object> getVendorProperties() {
        Map<String, Object> properties = new HashMap<>();
        properties.put("hibernate.dialect", "org.hibernate.dialect.PostgreSQLDialect");
    }

}

How can I analyze a heap dump in IntelliJ? (memory leak)

You can also use VisualVM Launcher to launch VisualVM from within IDEA. https://plugins.jetbrains.com/plugin/7115?pr=idea I personally find this more convenient.

Spring Boot, Spring Data JPA with multiple DataSources

here is my solution. base on spring-boot.1.2.5.RELEASE.

application.properties

first.datasource.driver-class-name=com.mysql.jdbc.Driver
first.datasource.url=jdbc:mysql://127.0.0.1:3306/test
first.datasource.username=
first.datasource.password=
first.datasource.validation-query=select 1

second.datasource.driver-class-name=com.mysql.jdbc.Driver
second.datasource.url=jdbc:mysql://127.0.0.1:3306/test2
second.datasource.username=
second.datasource.password=
second.datasource.validation-query=select 1

DataSourceConfig.java

@Configuration
public class DataSourceConfig {
    @Bean
    @Primary
    @ConfigurationProperties(prefix="first.datasource")
    public DataSource firstDataSource() {
        DataSource ds =  DataSourceBuilder.create().build();
        return ds;
    }

    @Bean
    @ConfigurationProperties(prefix="second.datasource")
    public DataSource secondDataSource() {
        DataSource ds =  DataSourceBuilder.create().build();
        return ds;
    }
}

How to include js and CSS in JSP with spring MVC

You cant directly access anything under the WEB-INF foldere. When browsers request your CSS file, they can not see inside the WEB-INF folder.

Try putting your files css/css folder under WebContent.

And add the following in dispatcher servlet to grant access ,

<mvc:resources mapping="/css/**" location="/css/" />

similarly for your js files . A Nice example here on this

Spring Hibernate - Could not obtain transaction-synchronized Session for current thread

My Database table has mismatch column name with the Java Object (@Entity) which leads to throw the above exception.

By updating the table with appropriate column name resolves this issue.

I have filtered my Excel data and now I want to number the rows. How do I do that?

I had the same problem. I'm no expert but this is the solution we used: Before you filter your data, first create a temporary column to populate your entire data set with your original sort order. Auto number the temporary "original sort order" column. Now filter your data. Copy and paste the filtered data into a new worksheet. This will move only the filtered data to the new sheet so that your row numbers will become consecutive. Now auto number your desired field. Go back to your original worksheet and delete the filtered rows. Copy and paste the newly numbered data from the secondary sheet onto the bottom of your original worksheet. Then clear your filter and sort the worksheet by the temporary "original sort order" column. This will put your newly numbered data back into its original order and you can then delete the temporary column.

No found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations:

Could me multiple reason for this. But you want might forget to add as @Bean for component which you have did @Autowired.

In my case, i have forgot to decorate with @Bean which causing this issue.

Cannot start GlassFish 4.1 from within Netbeans 8.0.1 Service area

you can easily resolve this problem by changing the port number of glassfish.

Go to glassfich configuration File domain.xml which is located under GlassFish_Server\glassfish\domains\domain1\config.

Open this file, then change the following line:

<network-listener port="8080" protocol="http-listener-1" transport="tcp" 
name="http-listener-1" thread-pool="http-thread-pool"></network-listener>  

replace 8080 by 9090 for example, then save file and run glassfish again. it should nicely work.

Difference between Amazon EC2 and AWS Elastic Beanstalk

First off, EC2 and Elastic Compute Cloud are the same thing.

Next, AWS encompasses the range of Web Services that includes EC2 and Elastic Beanstalk. It also includes many others such as S3, RDS, DynamoDB, and all the others.

EC2

EC2 is Amazon's service that allows you to create a server (AWS calls these instances) in the AWS cloud. You pay by the hour and only what you use. You can do whatever you want with this instance as well as launch n number of instances.

Elastic Beanstalk

Elastic Beanstalk is one layer of abstraction away from the EC2 layer. Elastic Beanstalk will setup an "environment" for you that can contain a number of EC2 instances, an optional database, as well as a few other AWS components such as a Elastic Load Balancer, Auto-Scaling Group, Security Group. Then Elastic Beanstalk will manage these items for you whenever you want to update your software running in AWS. Elastic Beanstalk doesn't add any cost on top of these resources that it creates for you. If you have 10 hours of EC2 usage, then all you pay is 10 compute hours.

Running Wordpress

For running Wordpress, it is whatever you are most comfortable with. You could run it straight on a single EC2 instance, you could use a solution from the AWS Marketplace, or you could use Elastic Beanstalk.

What to pick?

In the case that you want to reduce system operations and just focus on the website, then Elastic Beanstalk would be the best choice for that. Elastic Beanstalk supports a PHP stack (as well as others). You can keep your site in version control and easily deploy to your environment whenever you make changes. It will also setup an Autoscaling group which can spawn up more EC2 instances if traffic is growing.

Here's the first result off of Google when searching for "elastic beanstalk wordpress": https://www.otreva.com/blog/deploying-wordpress-amazon-web-services-aws-ec2-rds-via-elasticbeanstalk/

80-characters / right margin line in Sublime Text 3

For this to work, your font also needs to be set to monospace.
If you think about it, lines can't otherwise line up perfectly perfectly.

This answer is detailed at sublime text forum:
http://www.sublimetext.com/forum/viewtopic.php?f=3&p=42052
This answer has links for choosing an appropriate font for your OS,
and gives an answer to an edge case of fonts not lining up.

Another website that lists great monospaced free fonts for programmers. http://hivelogic.com/articles/top-10-programming-fonts

On stackoverflow, see:

Michael Ruth's answer here: How to make ruler always be shown in Sublime text 2?

MattDMo's answer here: What is the default font of Sublime Text?

I have rulers set at the following:
30
50 (git commit message titles should be limited to 50 characters)
72 (git commit message details should be limited to 72 characters)
80 (Windows Command Console Window maxes out at 80 character width)

Other viewing environments that benefit from shorter lines: github: there is no word wrap when viewing a file online
So, I try to keep .js .md and other files at 70-80 characters.
Windows Console: 80 characters.

Classpath resource not found when running as jar

I've create a ClassPathResourceReader class in a java 8 way to make easy read files from classpath

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.stream.Collectors;

import org.springframework.core.io.ClassPathResource;

public final class ClassPathResourceReader {

    private final String path;

    private String content;

    public ClassPathResourceReader(String path) {
        this.path = path;
    }

    public String getContent() {
        if (content == null) {
            try {
                ClassPathResource resource = new ClassPathResource(path);
                BufferedReader reader = new BufferedReader(new InputStreamReader(resource.getInputStream()));
                content = reader.lines().collect(Collectors.joining("\n"));
                reader.close();
            } catch (IOException ex) {
                throw new RuntimeException(ex);
            }
        }
        return content;
    }
}

Utilization:

String content = new ClassPathResourceReader("data.sql").getContent();

What is the OAuth 2.0 Bearer Token exactly?

A bearer token is like a currency note e.g 100$ bill . One can use the currency note without being asked any/many questions.

Bearer Token A security token with the property that any party in possession of the token (a "bearer") can use the token in any way that any other party in possession of it can. Using a bearer token does not require a bearer to prove possession of cryptographic key material (proof-of-possession).

TransactionRequiredException Executing an update/delete query

import org.hibernate.Criteria;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.transaction.annotation.Transactional;


    @Transactional
    public int changepassword(String password, long mobile) {
        // TODO Auto-generated method stub
        session = factory.getCurrentSession();
        Query query = session.createQuery("update User u set u.password='" + password + "' where u.mobile=" + mobile);
        int result = query.executeUpdate();

        return result;
    }
add this code 200% it will work... might scenario is diff but write like this:)

Spring Boot application.properties value not populating

Actually, For me below works fine.

@Component
public class MyBean {

   public static String prop;

   @Value("${some.prop}")
   public void setProp(String prop) {
      this.prop= prop;
   }

   public MyBean() {

   }

   @PostConstruct
   public void init() {
      System.out.println("================== " + prop + "================== ");
   }

}

Now whereever i want, just invoke

MyBean.prop

it will return value.

Multipart File upload Spring Boot

   @Bean
    MultipartConfigElement multipartConfigElement() {
        MultipartConfigFactory factory = new MultipartConfigFactory();
        factory.setMaxFileSize("5120MB");
        factory.setMaxRequestSize("5120MB");
        return factory.createMultipartConfig();
    }

put it in class where you are defining beans

Perform curl request in javascript?

Yes, use getJSONP. It's the only way to make cross domain/server async calls. (*Or it will be in the near future). Something like

$.getJSON('your-api-url/validate.php?'+$(this).serialize+'callback=?', function(data){
if(data)console.log(data);
});

The callback parameter will be filled in automatically by the browser, so don't worry.

On the server side ('validate.php') you would have something like this

<?php
if(isset($_GET))
{
//if condition is met
echo $_GET['callback'] . '(' . "{'message' : 'success', 'userID':'69', 'serial' : 'XYZ99UAUGDVD&orwhatever'}". ')';
}
else echo json_encode(array('error'=>'failed'));
?>

Spring Boot Remove Whitelabel Error Page

I am using Spring Boot version 2.1.2 and the errorAttributes.getErrorAttributes() signature didn't work for me (in acohen's response). I wanted a JSON type response so I did a little digging and found this method did exactly what I needed.

I got most of my information from this thread as well as this blog post.

First, I created a CustomErrorController that Spring will look for to map any errors to.

package com.example.error;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.web.servlet.error.ErrorAttributes;
import org.springframework.boot.web.servlet.error.ErrorController;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.WebRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.HashMap;
import java.util.Map;

@RestController
public class CustomErrorController implements ErrorController {

    private static final String PATH = "error";

    @Value("${debug}")
    private boolean debug;

    @Autowired
    private ErrorAttributes errorAttributes;

    @RequestMapping(PATH)
    @ResponseBody
    public CustomHttpErrorResponse error(WebRequest request, HttpServletResponse response) {
        return new CustomHttpErrorResponse(response.getStatus(), getErrorAttributes(request));
    }

    public void setErrorAttributes(ErrorAttributes errorAttributes) {
        this.errorAttributes = errorAttributes;
    }

    @Override
    public String getErrorPath() {
        return PATH;
    }

    private Map<String, Object> getErrorAttributes(WebRequest request) {
        Map<String, Object> map = new HashMap<>();
        map.putAll(this.errorAttributes.getErrorAttributes(request, this.debug));
        return map;
    }
}

Second, I created a CustomHttpErrorResponse class to return the error as JSON.

package com.example.error;

import java.util.Map;

public class CustomHttpErrorResponse {

    private Integer status;
    private String path;
    private String errorMessage;
    private String timeStamp;
    private String trace;

    public CustomHttpErrorResponse(int status, Map<String, Object> errorAttributes) {
        this.setStatus(status);
        this.setPath((String) errorAttributes.get("path"));
        this.setErrorMessage((String) errorAttributes.get("message"));
        this.setTimeStamp(errorAttributes.get("timestamp").toString());
        this.setTrace((String) errorAttributes.get("trace"));
    }

    // getters and setters
}

Finally, I had to turn off the Whitelabel in the application.properties file.

server.error.whitelabel.enabled=false

This should even work for xml requests/responses. But I haven't tested that. It did exactly what I was looking for since I was creating a RESTful API and only wanted to return JSON.

Understanding PrimeFaces process/update and JSF f:ajax execute/render attributes

<p:commandXxx process> <p:ajax process> <f:ajax execute>

The process attribute is server side and can only affect UIComponents implementing EditableValueHolder (input fields) or ActionSource (command fields). The process attribute tells JSF, using a space-separated list of client IDs, which components exactly must be processed through the entire JSF lifecycle upon (partial) form submit.

JSF will then apply the request values (finding HTTP request parameter based on component's own client ID and then either setting it as submitted value in case of EditableValueHolder components or queueing a new ActionEvent in case of ActionSource components), perform conversion, validation and updating the model values (EditableValueHolder components only) and finally invoke the queued ActionEvent (ActionSource components only). JSF will skip processing of all other components which are not covered by process attribute. Also, components whose rendered attribute evaluates to false during apply request values phase will also be skipped as part of safeguard against tampered requests.

Note that it's in case of ActionSource components (such as <p:commandButton>) very important that you also include the component itself in the process attribute, particularly if you intend to invoke the action associated with the component. So the below example which intends to process only certain input component(s) when a certain command component is invoked ain't gonna work:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="foo" action="#{bean.action}" />

It would only process the #{bean.foo} and not the #{bean.action}. You'd need to include the command component itself as well:

<p:inputText id="foo" value="#{bean.foo}" />
<p:commandButton process="@this foo" action="#{bean.action}" />

Or, as you apparently found out, using @parent if they happen to be the only components having a common parent:

<p:panel><!-- Type doesn't matter, as long as it's a common parent. -->
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@parent" action="#{bean.action}" />
</p:panel>

Or, if they both happen to be the only components of the parent UIForm component, then you can also use @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" />
    <p:commandButton process="@form" action="#{bean.action}" />
</h:form>

This is sometimes undesirable if the form contains more input components which you'd like to skip in processing, more than often in cases when you'd like to update another input component(s) or some UI section based on the current input component in an ajax listener method. You namely don't want that validation errors on other input components are preventing the ajax listener method from being executed.

Then there's the @all. This has no special effect in process attribute, but only in update attribute. A process="@all" behaves exactly the same as process="@form". HTML doesn't support submitting multiple forms at once anyway.

There's by the way also a @none which may be useful in case you absolutely don't need to process anything, but only want to update some specific parts via update, particularly those sections whose content doesn't depend on submitted values or action listeners.

Noted should be that the process attribute has no influence on the HTTP request payload (the amount of request parameters). Meaning, the default HTML behavior of sending "everything" contained within the HTML representation of the <h:form> will be not be affected. In case you have a large form, and want to reduce the HTTP request payload to only these absolutely necessary in processing, i.e. only these covered by process attribute, then you can set the partialSubmit attribute in PrimeFaces Ajax components as in <p:commandXxx ... partialSubmit="true"> or <p:ajax ... partialSubmit="true">. You can also configure this 'globally' by editing web.xml and add

<context-param>
    <param-name>primefaces.SUBMIT</param-name>
    <param-value>partial</param-value>
</context-param>

Alternatively, you can also use <o:form> of OmniFaces 3.0+ which defaults to this behavior.

The standard JSF equivalent to the PrimeFaces specific process is execute from <f:ajax execute>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Also, it may be useful to know that <p:commandXxx process> defaults to @form while <p:ajax process> and <f:ajax execute> defaults to @this. Finally, it's also useful to know that process supports the so-called "PrimeFaces Selectors", see also How do PrimeFaces Selectors as in update="@(.myClass)" work?


<p:commandXxx update> <p:ajax update> <f:ajax render>

The update attribute is client side and can affect the HTML representation of all UIComponents. The update attribute tells JavaScript (the one responsible for handling the ajax request/response), using a space-separated list of client IDs, which parts in the HTML DOM tree need to be updated as response to the form submit.

JSF will then prepare the right ajax response for that, containing only the requested parts to update. JSF will skip all other components which are not covered by update attribute in the ajax response, hereby keeping the response payload small. Also, components whose rendered attribute evaluates to false during render response phase will be skipped. Note that even though it would return true, JavaScript cannot update it in the HTML DOM tree if it was initially false. You'd need to wrap it or update its parent instead. See also Ajax update/render does not work on a component which has rendered attribute.

Usually, you'd like to update only the components which really need to be "refreshed" in the client side upon (partial) form submit. The example below updates the entire parent form via @form:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@form" />
</h:form>

(note that process attribute is omitted as that defaults to @form already)

Whilst that may work fine, the update of input and command components is in this particular example unnecessary. Unless you change the model values foo and bar inside action method (which would in turn be unintuitive in UX perspective), there's no point of updating them. The message components are the only which really need to be updated:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="foo_m bar_m" />
</h:form>

However, that gets tedious when you have many of them. That's one of the reasons why PrimeFaces Selectors exist. Those message components have in the generated HTML output a common style class of ui-message, so the following should also do:

<h:form>
    <p:inputText id="foo" value="#{bean.foo}" required="true" />
    <p:message id="foo_m" for="foo" />
    <p:inputText id="bar" value="#{bean.bar}" required="true" />
    <p:message id="bar_m" for="bar" />
    <p:commandButton action="#{bean.action}" update="@(.ui-message)" />
</h:form>

(note that you should keep the IDs on message components, otherwise @(...) won't work! Again, see How do PrimeFaces Selectors as in update="@(.myClass)" work? for detail)

The @parent updates only the parent component, which thus covers the current component and all siblings and their children. This is more useful if you have separated the form in sane groups with each its own responsibility. The @this updates, obviously, only the current component. Normally, this is only necessary when you need to change one of the component's own HTML attributes in the action method. E.g.

<p:commandButton action="#{bean.action}" update="@this" 
    oncomplete="doSomething('#{bean.value}')" />

Imagine that the oncomplete needs to work with the value which is changed in action, then this construct wouldn't have worked if the component isn't updated, for the simple reason that oncomplete is part of generated HTML output (and thus all EL expressions in there are evaluated during render response).

The @all updates the entire document, which should be used with care. Normally, you'd like to use a true GET request for this instead by either a plain link (<a> or <h:link>) or a redirect-after-POST by ?faces-redirect=true or ExternalContext#redirect(). In effects, process="@form" update="@all" has exactly the same effect as a non-ajax (non-partial) submit. In my entire JSF career, the only sensible use case I encountered for @all is to display an error page in its entirety in case an exception occurs during an ajax request. See also What is the correct way to deal with JSF 2.0 exceptions for AJAXified components?

The standard JSF equivalent to the PrimeFaces specific update is render from <f:ajax render>. It behaves exactly the same except that it doesn't support a comma-separated string while the PrimeFaces one does (although I personally recommend to just stick to space-separated convention), nor the @parent keyword. Both update and render defaults to @none (which is, "nothing").


See also:

How to create an alert message in jsp page after submit process is complete

in your servlet

 request.setAttribute("submitDone","done");
 return mapping.findForward("success");

In your jsp

<c:if test="${not empty submitDone}">
  <script>alert("Form submitted");
</script></c:if>

Creating lowpass filter in SciPy - understanding methods and units

A few comments:

  • The Nyquist frequency is half the sampling rate.
  • You are working with regularly sampled data, so you want a digital filter, not an analog filter. This means you should not use analog=True in the call to butter, and you should use scipy.signal.freqz (not freqs) to generate the frequency response.
  • One goal of those short utility functions is to allow you to leave all your frequencies expressed in Hz. You shouldn't have to convert to rad/sec. As long as you express your frequencies with consistent units, the scaling in the utility functions takes care of the normalization for you.

Here's my modified version of your script, followed by the plot that it generates.

import numpy as np
from scipy.signal import butter, lfilter, freqz
import matplotlib.pyplot as plt


def butter_lowpass(cutoff, fs, order=5):
    nyq = 0.5 * fs
    normal_cutoff = cutoff / nyq
    b, a = butter(order, normal_cutoff, btype='low', analog=False)
    return b, a

def butter_lowpass_filter(data, cutoff, fs, order=5):
    b, a = butter_lowpass(cutoff, fs, order=order)
    y = lfilter(b, a, data)
    return y


# Filter requirements.
order = 6
fs = 30.0       # sample rate, Hz
cutoff = 3.667  # desired cutoff frequency of the filter, Hz

# Get the filter coefficients so we can check its frequency response.
b, a = butter_lowpass(cutoff, fs, order)

# Plot the frequency response.
w, h = freqz(b, a, worN=8000)
plt.subplot(2, 1, 1)
plt.plot(0.5*fs*w/np.pi, np.abs(h), 'b')
plt.plot(cutoff, 0.5*np.sqrt(2), 'ko')
plt.axvline(cutoff, color='k')
plt.xlim(0, 0.5*fs)
plt.title("Lowpass Filter Frequency Response")
plt.xlabel('Frequency [Hz]')
plt.grid()


# Demonstrate the use of the filter.
# First make some data to be filtered.
T = 5.0         # seconds
n = int(T * fs) # total number of samples
t = np.linspace(0, T, n, endpoint=False)
# "Noisy" data.  We want to recover the 1.2 Hz signal from this.
data = np.sin(1.2*2*np.pi*t) + 1.5*np.cos(9*2*np.pi*t) + 0.5*np.sin(12.0*2*np.pi*t)

# Filter the data, and plot both the original and filtered signals.
y = butter_lowpass_filter(data, cutoff, fs, order)

plt.subplot(2, 1, 2)
plt.plot(t, data, 'b-', label='data')
plt.plot(t, y, 'g-', linewidth=2, label='filtered data')
plt.xlabel('Time [sec]')
plt.grid()
plt.legend()

plt.subplots_adjust(hspace=0.35)
plt.show()

lowpass example

No serializer found for class org.hibernate.proxy.pojo.javassist.Javassist?

This Exception

org.springframework.http.converter.HttpMessageNotWritableException

getting because, I hope so, your are sending response output as Serializable object.
This is problem occurring in spring. To over come this issue, send POJO object as response output.

Example :

    @Entity
    @Table(name="user_details")
    public class User implements Serializable{

        @Id
        @GeneratedValue(strategy= GenerationType.IDENTITY)
        @Column(name="id")
        private Integer id;

        @Column(name="user_name")
        private String userName;

        @Column(name="email_id")
        private String emailId;

        @Column(name="phone_no")
        private String phone;

//setter and getters

POJO class:

public class UserVO {

    private int Id;
    private String userName;
    private String emailId;
    private String phone;
    private Integer active;

//setter and getters

In controller convert the serilizable object fields to POJO class fields and return pojo class as output.

         User u= userService.getdetials(); // get data from database

        UserVO userVo= new UserVO();  // created pojo class object

        userVo.setId(u.getId());
        userVo.setEmailId(u.getEmailId());
        userVo.setActive(u.getActive());
        userVo.setPhone(u.getPhone());
        userVo.setUserName(u.getUserName());
       retunr userVo;  //finally send pojo object as output.

Error: org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain;charset=UTF-8' not supported

Ok - for me the source of the problem was in serialisation/deserialisation. The object that was being sent and received was as follows where the code is submitted and the code and maskedPhoneNumber is returned.

@ApiObject(description = "What the object is for.")
@JsonIgnoreProperties(ignoreUnknown = true)
public class CodeVerification {

    @ApiObjectField(description = "The code which is to be verified.")
    @NotBlank(message = "mandatory")
    private final String code;

    @ApiObjectField(description = "The masked mobile phone number to which the code was verfied against.")
    private final String maskedMobileNumber;

    public codeVerification(@JsonProperty("code") String code, String maskedMobileNumber) {
        this.code = code;
        this.maskedMobileNumber = maskedMobileNumber;
    }

    public String getcode() {
        return code;
    }

    public String getMaskedMobileNumber() {
        return maskedMobileNumber;
    }
}

The problem was that I didn't have a JsonProperty defined for the maskedMobileNumber in the constructor. i.e. Constructor should have been

public codeVerification(@JsonProperty("code") String code, @JsonProperty("maskedMobileNumber") String maskedMobileNumber) {
    this.code = code;
    this.maskedMobileNumber = maskedMobileNumber;
}

How to create JNDI context in Spring Boot with Embedded Tomcat Container

In SpringBoot 2.1, I found another solution. Extend standard factory class method getTomcatWebServer. And then return it as a bean from anywhere.

public class CustomTomcatServletWebServerFactory extends TomcatServletWebServerFactory {

    @Override
    protected TomcatWebServer getTomcatWebServer(Tomcat tomcat) {
        System.setProperty("catalina.useNaming", "true");
        tomcat.enableNaming();
        return new TomcatWebServer(tomcat, getPort() >= 0);
    }
}

@Component
public class TomcatConfiguration {
    @Bean
    public ConfigurableServletWebServerFactory webServerFactory() {
        TomcatServletWebServerFactory factory = new CustomTomcatServletWebServerFactory();

        return factory;
    }

Loading resources from context.xml doesn't work though. Will try to find out.

How to stick table header(thead) on top while scrolling down the table rows with fixed header(navbar) in bootstrap 3?

_x000D_
_x000D_
.contents {
  width: 50%;
  border: 1px solid black;
  height: 300px;
  overflow: auto;
}

table {
  position: relative;
}

th {
  position: sticky;
  top: 0;
  background: #ffffff;
}
_x000D_
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">
<div class="contents">
  <table class="table">
    <thead>
      <tr>
        <th>colunn 1</th>
        <th>colunn 2</th>
        <th>colunn 3</th>
        <th>colunn 4</th>
      </tr>
    </thead>
    <tbody>
      <tr>
        <td>Example 1</td>
        <td>Example 2</td>
        <td>Example 3</td>
        <td>Example 4</td>
        <tr>
          <tr>
            <td>Example 1</td>
            <td>Example 2</td>
            <td>Example 3</td>
            <td>Example 4</td>
            <tr>
              <tr>
                <td>Example 1</td>
                <td>Example 2</td>
                <td>Example 3</td>
                <td>Example 4</td>
                <tr>
                  <tr>
                    <td>Example 1</td>
                    <td>Example 2</td>
                    <td>Example 3</td>
                    <td>Example 4</td>
                    <tr>
                      <tr>
                        <td>Example 1</td>
                        <td>Example 2</td>
                        <td>Example 3</td>
                        <td>Example 4</td>
                        <tr>
                          <tr>
                            <td>Example 1</td>
                            <td>Example 2</td>
                            <td>Example 3</td>
                            <td>Example 4</td>
                            <tr>
                              <tr>
                                <td>Example 1</td>
                                <td>Example 2</td>
                                <td>Example 3</td>
                                <td>Example 4</td>
                                <tr>
                                  <tr>
                                    <td>Example 1</td>
                                    <td>Example 2</td>
                                    <td>Example 3</td>
                                    <td>Example 4</td>
                                    <tr>
                                      <tr>
                                        <td>Example 1</td>
                                        <td>Example 2</td>
                                        <td>Example 3</td>
                                        <td>Example 4</td>
                                        <tr>
                                          <tr>
                                            <td>Example 1</td>
                                            <td>Example 2</td>
                                            <td>Example 3</td>
                                            <td>Example 4</td>
                                            <tr>
    </tbody>
  </table>
</div>
_x000D_
_x000D_
_x000D_

Failed to load ApplicationContext from Unit Test: FileNotFound

Try with the relative path using *

  @ContextConfiguration(locations = {
"classpath*:spring/applicationContext.xml",
"classpath*:spring/applicationContext-jpa.xml",
"classpath*:spring/applicationContext-security.xml" })

If not look if your xml are really on resources/spring/.

Finally try just on without location

 @ContextConfiguration({"classpath*:spring/applicationContext.xml"})

The other error that you´re showing is because you have this tag duplicated on applicationContext.xml and applicationContext-security.xml

 Duplicate <global-method-security>

javac: invalid target release: 1.8

If this error occurs when running a Gradle (or Maven) task, you need to modify that build tool configuration to point to your installation of Java JDK 1.8 following this route:

File -> Settings -> Build, Execution, Deployment -> Build Tools -> Gradle

There you check the Linked Gradle project is the one you are working on and select the Gradle JVM (You missed this when you imported the gradle project into IntelliJ)

enter image description here

Remember when importing a Gradle (or Maven) project to set the target JVM correctly here: enter image description here

Could not extract response: no suitable HttpMessageConverter found for response type

Since you return to the client just String and its content type == 'text/plain', there is no any chance for default converters to determine how to convert String response to the FFSampleResponseHttp object.

The simple way to fix it:

  • remove expected-response-type from <int-http:outbound-gateway>
  • add to the replyChannel1 <json-to-object-transformer>

Otherwise you should write your own HttpMessageConverter to convert the String to the appropriate object.

To make it work with MappingJackson2HttpMessageConverter (one of default converters) and your expected-response-type, you should send your reply with content type = 'application/json'.

If there is a need, just add <header-enricher> after your <service-activator> and before sending a reply to the <int-http:inbound-gateway>.

So, it's up to you which solution to select, but your current state doesn't work, because of inconsistency with default configuration.

UPDATE

OK. Since you changed your server to return FfSampleResponseHttp object as HTTP response, not String, just add contentType = 'application/json' header before sending the response for the HTTP and MappingJackson2HttpMessageConverter will do the stuff for you - your object will be converted to JSON and with correct contentType header.

From client side you should come back to the expected-response-type="com.mycompany.MyChannel.model.FFSampleResponseHttp" and MappingJackson2HttpMessageConverter should do the stuff for you again.

Of course you should remove <json-to-object-transformer> from you message flow after <int-http:outbound-gateway>.

How can I trigger the click event of another element in ng-click using angularjs?

If your input and button are siblings (and they are in your case OP):

<input id="upload"
    type="file"
    ng-file-select="onFileSelect($files)"
    style="display: none;">

<button type="button" uploadfile>Upload</button>

Use a directive to bind the click of your button to the file input like so:

app.directive('uploadfile', function () {
    return {
      restrict: 'A',
      link: function(scope, element) {

        element.bind('click', function(e) {
            angular.element(e.target).siblings('#upload').trigger('click');
        });
      }
    };
});

Store a closure as a variable in Swift

I've provide an example not sure if this is what you're after.

var completionHandler: (_ value: Float) -> ()

func printFloat(value: Float) {
    print(value)
}

completionHandler = printFloat

completionHandler(5)

It simply prints 5 using the completionHandler variable declared.

Spring data jpa- No bean named 'entityManagerFactory' is defined; Injection of autowired dependencies failed

I had the same problem and got it resolved by deleting .m2 maven repo (C:\Users\user\ .m2)

Label encoding across multiple columns in scikit-learn

You can easily do this though,

df.apply(LabelEncoder().fit_transform)

EDIT2:

In scikit-learn 0.20, the recommended way is

OneHotEncoder().fit_transform(df)

as the OneHotEncoder now supports string input. Applying OneHotEncoder only to certain columns is possible with the ColumnTransformer.

EDIT3:

Since this answer is over a year ago, and generated many upvotes (including a bounty), I should probably extend this further.

For inverse_transform and transform, you have to do a little bit of hack.

from collections import defaultdict
d = defaultdict(LabelEncoder)

With this, you now retain all columns LabelEncoder as dictionary.

# Encoding the variable
fit = df.apply(lambda x: d[x.name].fit_transform(x))

# Inverse the encoded
fit.apply(lambda x: d[x.name].inverse_transform(x))

# Using the dictionary to label future data
df.apply(lambda x: d[x.name].transform(x))

MOAR EDIT:

Using Neuraxle's FlattenForEach step, it's possible to do this as well to use the same LabelEncoder on all the flattened data at once:

FlattenForEach(LabelEncoder(), then_unflatten=True).fit_transform(df)

For using separate LabelEncoders depending for your columns of data, or if only some of your columns of data needs to be label-encoded and not others, then using a ColumnTransformer is a solution that allows for more control on your column selection and your LabelEncoder instances.

bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?

Although BeautifulSoup supports the HTML parser by default If you want to use any other third-party Python parsers you need to install that external parser like(lxml).

soup_object= BeautifulSoup(markup,"html.parser") #Python HTML parser

But if you don't specified any parser as parameter you will get an warning that no parser specified.

soup_object= BeautifulSoup(markup) #Warnning

To use any other external parser you need to install it and then need to specify it. like

pip install lxml

soup_object= BeautifulSoup(markup,'lxml') # C dependent parser 

External parser have c and python dependency which may have some advantage and disadvantage.

SSL Error: unable to get local issuer certificate

If you are a linux user Update node to a later version by running

sudo apt update

 sudo apt install build-essential checkinstall libssl-dev

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.35.1/install.sh | bash

nvm --version

nvm ls

nvm ls-remote

nvm install [version.number]

this should solve your problem

Which is best data type for phone number in MySQL and what should Java type mapping for it be?

you can use var-char,String,and int ,it depends on you, if you use only country code with mobile number than you can use int,if you use special formate for number than use String or var-char type, if you use var-char then must defile size of number and restrict from user.

java.lang.ClassNotFoundException: org.springframework.core.io.Resource

Right-Click on your project -> Properties -> Deployment Assembly.

On the Left-hand panel Click 'Add' and add the 'Project and External Dependencies'.

'Project and External Dependencies' will have all the spring related jars deployed along with your application

self.tableView.reloadData() not working in Swift

Try it: tableView.reloadSections(IndexSet(integersIn: 0...0), with: .automatic) It helped me

connecting MySQL server to NetBeans

check the context.xml file in Web Pages -> META-INF, the username="user" must be the same as the database user, in my case was root, that solved the connection error

Hope helps

Spring Boot - Cannot determine embedded database driver class for database type NONE

You can add

spring.autoconfigure.exclude=org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration   

to your application.properties file.

Mipmap drawables for icons

res/
mipmap-mdpi/ic_launcher.png (48x48 pixels)
mipmap-hdpi/ic_launcher.png (72x72)
mipmap-xhdpi/ic_launcher.png (96x96)
mipmap-xxhdpi/ic_launcher.png (144x144)
mipmap-xxxhdpi/ic_launcher.png (192x192)

MipMap for app icon for launcher

http://android-developers.blogspot.co.uk/2014/10/getting-your-apps-ready-for-nexus-6-and.html

https://androidbycode.wordpress.com/2015/02/14/goodbye-launcher-drawables-hello-mipmaps/

Spring boot Security Disable security

The easiest way for Spring Boot 2 without dependencies or code changes is just:

spring:
  autoconfigure:
    exclude: org.springframework.boot.autoconfigure.security.servlet.SecurityAutoConfiguration

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'MyController':

Copied from the stacktrace:

BeanInstantiationException: Could not instantiate bean class [com.gestEtu.project.model.dao.CompteDAOHib]: No default constructor found; nested exception is java.lang.NoSuchMethodException: com.gestEtu.project.model.dao.CompteDAOHib.<init>()

By default, Spring will try to instantiate beans by calling a default (no-arg) constructor. The problem in your case is that the implementation of the CompteDAOHib has a constructor with a SessionFactory argument. By adding the @Autowired annotation to a constructor, Spring will attempt to find a bean of matching type, SessionFactory in your case, and provide it as a constructor argument, e.g.

@Autowired
public CompteDAOHib(SessionFactory sessionFactory) {
    // ...
}

Node/Express file upload

Here is a simplified version (the gist) of Mick Cullen's answer -- in part to prove that it needn't be very complex to implement this; in part to give a quick reference for anyone who isn't interested in reading pages and pages of code.


You have to make you app use connect-busboy:

var busboy = require("connect-busboy");
app.use(busboy());

This will not do anything until you trigger it. Within the call that handles uploading, do the following:

app.post("/upload", function(req, res) {
    if(req.busboy) {
        req.busboy.on("file", function(fieldName, fileStream, fileName, encoding, mimeType) {
            //Handle file stream here
        });
        return req.pipe(req.busboy);
    }
    //Something went wrong -- busboy was not loaded
});

Let's break this down:

  • You check if req.busboy is set (the middleware was loaded correctly)
  • You set up a "file" listener on req.busboy
  • You pipe the contents of req to req.busboy

Inside the file listener there are a couple of interesting things, but what really matters is the fileStream: this is a Readable, that can then be written to a file, like you usually would.

Pitfall: You must handle this Readable, or express will never respond to the request, see the busboy API (file section).

Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener

If you are sure you haven't messed the jar, then please clean the project and perform mvn clean install. This should solve the problem.

How to test Spring Data repositories?

If you're using Spring Boot, you can simply use @SpringBootTest to load in your ApplicationContext (which is what your stacktrace is barking at you about). This allows you to autowire in your spring-data repositories. Be sure to add @RunWith(SpringRunner.class) so the spring-specific annotations are picked up:

@RunWith(SpringRunner.class)
@SpringBootTest
public class OrphanManagementTest {

  @Autowired
  private UserRepository userRepository;

  @Test
  public void saveTest() {
    User user = new User("Tom");
    userRepository.save(user);
    Assert.assertNotNull(userRepository.findOne("Tom"));
  }
}

You can read more about testing in spring boot in their docs.

Using BeautifulSoup to extract text without tags

Just loop through all the <strong> tags and use next_sibling to get what you want. Like this:

for strong_tag in soup.find_all('strong'):
    print(strong_tag.text, strong_tag.next_sibling)

Demo:

from bs4 import BeautifulSoup

html = '''
<p>
  <strong class="offender">YOB:</strong> 1987<br />
  <strong class="offender">RACE:</strong> WHITE<br />
  <strong class="offender">GENDER:</strong> FEMALE<br />
  <strong class="offender">HEIGHT:</strong> 5'05''<br />
  <strong class="offender">WEIGHT:</strong> 118<br />
  <strong class="offender">EYE COLOR:</strong> GREEN<br />
  <strong class="offender">HAIR COLOR:</strong> BROWN<br />
</p>
'''

soup = BeautifulSoup(html)

for strong_tag in soup.find_all('strong'):
    print(strong_tag.text, strong_tag.next_sibling)

This gives you:

YOB:  1987
RACE:  WHITE
GENDER:  FEMALE
HEIGHT:  5'05''
WEIGHT:  118
EYE COLOR:  GREEN
HAIR COLOR:  BROWN

python BeautifulSoup parsing table

from behave import *
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.wait import WebDriverWait
from selenium.webdriver.support import expected_conditions as ec
import pandas as pd
import requests
from bs4 import BeautifulSoup
from tabulate import tabulate

class readTableDataFromDB: 
    def LookupValueFromColumnSingleKey(context, tablexpath, rowName, columnName):
        print("element present readData From Table")
        element = context.driver.find_elements_by_xpath(tablexpath+"/descendant::th")
        indexrow = 1
        indexcolumn = 1
        for values in element:
            valuepresent = values.text
            print("text present here::"+valuepresent+"rowName::"+rowName)
            if valuepresent.find(columnName) != -1:
                 print("current row"+str(indexrow) +"value"+valuepresent)
                 break
            else:
                 indexrow = indexrow+1    

        indexvalue = context.driver.find_elements_by_xpath(
            tablexpath+"/descendant::tr/td[1]")
        for valuescolumn in indexvalue:
            valuepresentcolumn = valuescolumn.text
            print("Team text present here::" +
                  valuepresentcolumn+"columnName::"+rowName)
            print(indexcolumn) 
            if valuepresentcolumn.find(rowName) != -1:
                print("current column"+str(indexcolumn) +
                      "value"+valuepresentcolumn)
                break
            else:
                indexcolumn = indexcolumn+1

        print("index column"+str(indexcolumn))
        print(tablexpath +"//descendant::tr["+str(indexcolumn)+"]/td["+str(indexrow)+"]")
        #lookupelement = context.driver.find_element_by_xpath(tablexpath +"//descendant::tr["+str(indexcolumn)+"]/td["+str(indexrow)+"]")
        #print(lookupelement.text)
        return context.driver.find_elements_by_xpath(tablexpath+"//descendant::tr["+str(indexcolumn)+"]/td["+str(indexrow)+"]")

    def LookupValueFromColumnTwoKeyssss(context, tablexpath, rowName, columnName, columnName1):
        print("element present readData From Table")
        element = context.driver.find_elements_by_xpath(
            tablexpath+"/descendant::th")
        indexrow = 1
        indexcolumn = 1
        indexcolumn1 = 1
        for values in element:
            valuepresent = values.text
            print("text present here::"+valuepresent)
            indexrow = indexrow+1
            if valuepresent == columnName:
                print("current row value"+str(indexrow)+"value"+valuepresent)
                break

        for values in element:
            valuepresent = values.text
            print("text present here::"+valuepresent)
            indexrow = indexrow+1
            if valuepresent.find(columnName1) != -1:
                print("current row value"+str(indexrow)+"value"+valuepresent)
                break

        indexvalue = context.driver.find_elements_by_xpath(
            tablexpath+"/descendant::tr/td[1]")
        for valuescolumn in indexvalue:
            valuepresentcolumn = valuescolumn.text
            print("Team text present here::"+valuepresentcolumn)
            print(indexcolumn)
            indexcolumn = indexcolumn+1
            if valuepresent.find(rowName) != -1:
                print("current column"+str(indexcolumn) +
                      "value"+valuepresentcolumn)
                break
        print("indexrow"+str(indexrow))
        print("index column"+str(indexcolumn))
        lookupelement = context.driver.find_element_by_xpath(
            tablexpath+"//descendant::tr["+str(indexcolumn)+"]/td["+str(indexrow)+"]")
        print(tablexpath +
              "//descendant::tr["+str(indexcolumn)+"]/td["+str(indexrow)+"]")
        print(lookupelement.text)
        return context.driver.find_element_by_xpath(tablexpath+"//descendant::tr["+str(indexrow)+"]/td["+str(indexcolumn)+"]")

How to set up datasource with Spring for HikariCP?

I have recently migrated from C3P0 to HikariCP in a Spring and Hibernate based project and it was not as easy as I had imagined and here I am sharing my findings.

For Spring Boot see my answer here

I have the following setup

  • Spring 4.3.8+
  • Hiberante 4.3.8+
  • Gradle 2.x
  • PostgreSQL 9.5

Some of the below configs are similar to some of the answers above but, there are differences.

Gradle stuff

In order to pull in the right jars, I needed to pull in the following jars

//latest driver because *brettw* see https://github.com/pgjdbc/pgjdbc/pull/849
compile 'org.postgresql:postgresql:42.2.0'
compile('com.zaxxer:HikariCP:2.7.6') {
    //they are pulled in separately elsewhere
    exclude group: 'org.hibernate', module: 'hibernate-core'
}

// Recommended to use HikariCPConnectionProvider by Hibernate in 4.3.6+    
compile('org.hibernate:hibernate-hikaricp:4.3.8.Final') {
        //they are pulled in separately elsewhere, to avoid version conflicts
        exclude group: 'org.hibernate', module: 'hibernate-core'
        exclude group: 'com.zaxxer', module: 'HikariCP'
}

// Needed for HikariCP logging if you use log4j
compile('org.slf4j:slf4j-simple:1.7.25')  
compile('org.slf4j:slf4j-log4j12:1.7.25') {
    //log4j pulled in separately, exclude to avoid version conflict
    exclude group: 'log4j', module: 'log4j'
}

Spring/Hibernate based configs

In order to get Spring & Hibernate to make use of Hikari Connection pool, you need to define the HikariDataSource and feed it into sessionFactory bean as shown below.

<!-- HikariCP Database bean -->
<bean id="dataSource" class="com.zaxxer.hikari.HikariDataSource" destroy-method="close">
    <constructor-arg ref="hikariConfig" />
</bean>

<!-- HikariConfig config that is fed to above dataSource -->
<bean id="hikariConfig" class="com.zaxxer.hikari.HikariConfig">
        <property name="poolName" value="SpringHikariPool" />
        <property name="dataSourceClassName" value="org.postgresql.ds.PGSimpleDataSource" />
        <property name="maximumPoolSize" value="20" />
        <property name="idleTimeout" value="30000" />

        <property name="dataSourceProperties">
            <props>
                <prop key="serverName">localhost</prop>
                <prop key="portNumber">5432</prop>
                <prop key="databaseName">dbname</prop>
                <prop key="user">dbuser</prop>
                <prop key="password">dbpassword</prop>
            </props>
        </property>
</bean>

<bean class="org.springframework.orm.hibernate4.LocalSessionFactoryBean" id="sessionFactory">
        <!-- Your Hikari dataSource below -->
        <property name="dataSource" ref="dataSource"/>
        <!-- your other configs go here -->
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.connection.provider_class">org.hibernate.hikaricp.internal.HikariCPConnectionProvider</prop>
                <!-- Remaining props goes here -->
            </props>
        </property>
 </bean>

Once the above are setup then, you need to add an entry to your log4j or logback and set the level to DEBUG to see Hikari Connection Pool start up.

Log4j1.2

<!-- Keep additivity=false to avoid duplicate lines -->
<logger additivity="false" name="com.zaxxer.hikari">
    <level value="debug"/>
    <!-- Your appenders goes here -->
</logger>

Logback

Via application.properties in Spring Boot

debug=true
logging.level.com.zaxxer.hikari.HikariConfig=DEBUG 

Using logback.xml

<logger name="com.zaxxer.hikari" level="DEBUG" additivity="false">
    <appender-ref ref="STDOUT" />
</logger>

With the above you should be all good to go! Obviously you need to customize the HikariCP pool configs in order to get the performance that it promises.

org.hibernate.hql.internal.ast.QuerySyntaxException: table is not mapped

It means your table is not mapped to the JPA. Either Name of the table is wrong (Maybe case sensitive), or you need to put an entry in the XML file.

Happy Coding :)

WebService Client Generation Error with JDK8

I run ant builds within Eclipse IDE (4.4, Luna, on Windows 7 x64). Rather than modifying the installed JRE lib or any ant scripts (I have multiple projects that include XJC in their builds), I prefer to change Eclipse Settings "External Tools Configurations" and add the following to the VM arguments for the Ant build configuration:

-Djavax.xml.accessExternalSchema=all

Spring Boot JPA - configuring auto reconnect

For those who want to do it from YAML with multiple data sources, there is a great blog post about it: https://springframework.guru/how-to-configure-multiple-data-sources-in-a-spring-boot-application/

It basically says you both need to configure data source properties and datasource like this:

@Bean
@Primary
@ConfigurationProperties("app.datasource.member")
public DataSourceProperties memberDataSourceProperties() {
    return new DataSourceProperties();
}

@Bean
@Primary
@ConfigurationProperties("app.datasource.member.hikari")
public DataSource memberDataSource() {
    return memberDataSourceProperties().initializeDataSourceBuilder()
            .type(HikariDataSource.class).build();
}

Do not forget to remove @Primary from other datasources.

Google OAUTH: The redirect URI in the request did not match a registered redirect URI

You need to go into the developer console and set

http://localhost:8080/WEBAPP/youtube-callback.html

as your callback URL.

This video is slightly outdated, as it shows the older Developer Console instead of the new one, however, the concepts should still apply. You need to find your project in the developer console and register a callback URL.

Printing Mongo query output to a file while in the mongo shell

AFAIK, there is no a interactive option for output to file, there is a previous SO question related with this: Printing mongodb shell output to File

However, you can log all the shell session if you invoked the shell with tee command:

$ mongo | tee file.txt
MongoDB shell version: 2.4.2
connecting to: test
> printjson({this: 'is a test'})
{ "this" : "is a test" }
> printjson({this: 'is another test'})
{ "this" : "is another test" }
> exit
bye

Then you'll get a file with this content:

MongoDB shell version: 2.4.2
connecting to: test
> printjson({this: 'is a test'})
{ "this" : "is a test" }
> printjson({this: 'is another test'})
{ "this" : "is another test" }
> exit
bye

To remove all the commands and keep only the json output, you can use a command similar to:

tail -n +3 file.txt | egrep -v "^>|^bye" > output.json

Then you'll get:

{ "this" : "is a test" }
{ "this" : "is another test" }

Configuration with name 'default' not found. Android Studio

If you're getting this error with react native, it may be due to a link to an NPM package that you removed (as it was in my case). After removing references to it in the settings.gradle and build.gradle files, I cleaned and rebuilt and it's as good as new :)

Name [jdbc/mydb] is not bound in this Context

You need a ResourceLink in your META-INF/context.xml file to make the global resource available to the web application.

 <ResourceLink name="jdbc/mydb"
             global="jdbc/mydb"
              type="javax.sql.DataSource" />

Why does my Spring Boot App always shutdown immediately after starting?

In my case I fixed this issue like below:-

  1. First I removed (apache) C:\Users\myuserId\.m2\repository\org\apache

  2. I added below dependencies in my pom.xml file

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    
  3. I have changed the default socket by adding below lines in resource file ..\yourprojectfolder\src\main\resourcesand\application.properties(I manually created this file)

     server.port=8099
     [email protected]@
    

    for that I have added below block in my pom.xml under <build> section.

      <build>
      .
      .
     <resources>
        <resource>
            <directory>src/main/resources</directory>
            <filtering>true</filtering>
        </resource>
    </resources>
       .
       .    
      </build>
    

My final pom.xml file look like

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.bhaiti</groupId>
    <artifactId>spring-boot-rest</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>spring-boot-rest</name>
    <description>Welcome project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>       

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
        <resources>
            <resource>
                <directory>src/main/resources</directory>
                <filtering>true</filtering>
            </resource>
        </resources>

    </build>


</project>

@RequestParam in Spring MVC handling optional parameters

Create 2 methods which handle the cases. You can instruct the @RequestMapping annotation to take into account certain parameters whilst mapping the request. That way you can nicely split this into 2 methods.

@RequestMapping (value="/submit/id/{id}", method=RequestMethod.GET, 
                 produces="text/xml", params={"logout"})
public String handleLogout(@PathVariable("id") String id, 
        @RequestParam("logout") String logout) { ... }

@RequestMapping (value="/submit/id/{id}", method=RequestMethod.GET, 
                 produces="text/xml", params={"name", "password"})
public String handleLogin(@PathVariable("id") String id, @RequestParam("name") 
        String username, @RequestParam("password") String password, 
        @ModelAttribute("submitModel") SubmitModel model, BindingResult errors) 
        throws LoginException {...}

Basic HTTP and Bearer Token Authentication

curl --anyauth

Tells curl to figure out authentication method by itself, and use the most secure one the remote site claims to support. This is done by first doing a request and checking the response- headers, thus possibly inducing an extra network round-trip. This is used instead of setting a specific authentication method, which you can do with --basic, --digest, --ntlm, and --negotiate.

Starting of Tomcat failed from Netbeans

This affects:

  • All versions of Tomcat starting from 8.5.3 onwards.
  • All versions of Netbeans up to 8.1 (It is fixed in Netbeans 8.2).

This is because Netbeans does not 'see' that tomcat is started, although it started just fine.

I have filed Bug #262749 with NetBeans.

Workaround

In the server.xml file, in the Connector element for HTTP/1.1, add the following attribute: server="Apache-Coyote/1.1".

Example:

<Connector
  connectionTimeout="20000"
  port="8080"
  protocol="HTTP/1.1"
  redirectPort="8443"
  server="Apache-Coyote/1.1"
/>

Cause

The reason for that is that prior to 8.5.3, the default was to set the server header as Apache-Coyote/1.1, while since 8.5.3 this default has now been changed to blank. Apparently Netbeans checks on this header.

Maybe in the future we can expect a fix in netbeans addressing this issue.

I was able to trace it back to a change in documentation.

Tomcat 8.5:

"Overrides the Server header for the http response. If set, the value for this attribute overrides any Server header set by a web application. If not set, any value specified by the application is used. If the application does not specify a value then no Server header is set."

Tomcat 8.0:

"Overrides the Server header for the http response. If set, the value for this attribute overrides the Tomcat default and any Server header set by a web application. If not set, any value specified by the application is used. If the application does not specify a value then Apache-Coyote/1.1 is used. Unless you are paranoid, you won't need this feature."

That explains the need for explicitly adding the server attribute since version 8.5.3.

org.apache.poi.POIXMLException: org.apache.poi.openxml4j.exceptions.InvalidFormatException:

You are trying to access an XLS file. However, you are using XSSFWorkbook and XSSFSheet class objects. These classes are mainly used for XLSX files.

For XLS file: HSSFWorkbook & HSSFSheet
For XLSX file: XSSFSheet & XSSFSheet

So in place of XSSFWorkbook use HSSFWorkbook and in place of XSSFSheet use HSSFSheet.

So your code should look like this after the changes are made:

HSSFWorkbook workbook = new HSSFWorkbook(file);

HSSFSheet sheet = workbook.getSheetAt(0);

Why is printing "B" dramatically slower than printing "#"?

Pure speculation is that you're using a terminal that attempts to do word-wrapping rather than character-wrapping, and treats B as a word character but # as a non-word character. So when it reaches the end of a line and searches for a place to break the line, it sees a # almost immediately and happily breaks there; whereas with the B, it has to keep searching for longer, and may have more text to wrap (which may be expensive on some terminals, e.g., outputting backspaces, then outputting spaces to overwrite the letters being wrapped).

But that's pure speculation.

Display Records From MySQL Database using JTable in Java

this is the easy way to do that you just need to download the jar file "rs2xml.jar" add it to your project and do that : 1- creat a connection 2- statment and resultset 3- creat a jtable 4- give the result set to DbUtils.resultSetToTableModel(rs) as define in this methode you well get your jtable so easy.

public void afficherAll(String tableName){
        String sql="select * from "+tableName;
        try {
            stmt=con.createStatement();
            rs=stmt.executeQuery(sql);
            tbContTable.setModel(DbUtils.resultSetToTableModel(rs));
        } catch (SQLException e) {
            // TODO Auto-generated catch block
             JOptionPane.showMessageDialog(null, e);
        }       
    }

How to write JUnit test with Spring Autowire?

A JUnit4 test with Autowired and bean mocking (Mockito):

// JUnit starts spring context
@RunWith(SpringRunner.class)
// spring load context configuration from AppConfig class
@ContextConfiguration(classes = AppConfig.class)
// overriding some properties with test values if you need
@TestPropertySource(properties = {
        "spring.someConfigValue=your-test-value",
})
public class PersonServiceTest {

    @MockBean
    private PersonRepository repository;

    @Autowired
    private PersonService personService; // uses PersonRepository    

    @Test
    public void testSomething() {
        // using Mockito
        when(repository.findByName(any())).thenReturn(Collection.emptyList());
        Person person = new Person();
        person.setName(null);

        // when
        boolean found = personService.checkSomething(person);

        // then
        assertTrue(found, "Something is wrong");
    }
}

Spring get current ApplicationContext

Even better than having it with @Autowired is to let it be injected via constructor. Find some arguments pro constructor injection here

@Component
public class MyClass{
  private final ApplicationContext applicationContext;

  public MyClass(ApplicationContext applicationContext){
    this.applicationContext = applicationContext;
  }

  //here will be your methods using the applicationcontext
}

Spring Boot: Unable to start EmbeddedWebApplicationContext due to missing EmbeddedServletContainerFactory bean

If you package it as a single jar and it's non web app try to load app context as below.

@SpringBootApplication

ApplicationContext ctx = new AnnotationConfigApplicationContext(Main.class);

Or use below plugin to package as a single jar

             <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>

you can specify the external configs by using below command to run

java -jar myproject.jar --spring.config.location=classpath:/default.properties,classpath:/override.properties

/http://docs.spring.io/spring-boot/docs/current/reference/htmlboot-features-external-config.html#boot-features-external-config-application-property-files

Note that if you are passing the properties as arguments then don't include @PropertySource("classpath:test.properties") it will override the parameters

Jboss server error : Failed to start service jboss.deployment.unit."jbpm-console.war"

I had the exact same problem, found that I was missing

<mdb>  
  <resource-adapter-ref resource-adapter-name="hornetq-ra"/>  
  <bean-instance-pool-ref pool-name="mdb-strict-max-pool"/>  
</mdb>  

under

<subsystem xmlns="urn:jboss:domain:ejb3:1.2">  

in standalone/configuration/standalone.xml

How to fix 'sudo: no tty present and no askpass program specified' error?

For the reference, in case someone else encounter the same issue, I was stuck during a good hour with this error which should not happen since I was using the NOPASSWD parameter.

What I did NOT know was that sudo may raise the exact same error message when there is no tty and the command the user try to launch is not part of the allowed command in the /etc/sudoers file.

Here a simplified example of my file content with my issue:

bguser ALL = NOPASSWD: \
    command_a arg_a, \
    command_b arg_b \
    command_c arg_c

When bguser will try to launch "sudo command_b arg_b" without any tty (bguser being used for some daemon), then he will encounter the error "no tty present and no askpass program specified".

Why?

Because a comma is missing at the end of line in the /etc/sudoers file...

(I even wonder if this is an expected behavior and not a bug in sudo since the correct error message for such case shoud be "Sorry, user bguser is not allowed to execute etc.")

How to get HttpClient to pass credentials along with the request?

What you are trying to do is get NTLM to forward the identity on to the next server, which it cannot do - it can only do impersonation which only gives you access to local resources. It won't let you cross a machine boundary. Kerberos authentication supports delegation (what you need) by using tickets, and the ticket can be forwarded on when all servers and applications in the chain are correctly configured and Kerberos is set up correctly on the domain. So, in short you need to switch from using NTLM to Kerberos.

For more on Windows Authentication options available to you and how they work start at: http://msdn.microsoft.com/en-us/library/ff647076.aspx

Can I compile all .cpp files in src/ to .o's in obj/, then link to binary in ./?

Makefile part of the question

This is pretty easy, unless you don't need to generalize try something like the code below (but replace space indentation with tabs near g++)

SRC_DIR := .../src
OBJ_DIR := .../obj
SRC_FILES := $(wildcard $(SRC_DIR)/*.cpp)
OBJ_FILES := $(patsubst $(SRC_DIR)/%.cpp,$(OBJ_DIR)/%.o,$(SRC_FILES))
LDFLAGS := ...
CPPFLAGS := ...
CXXFLAGS := ...

main.exe: $(OBJ_FILES)
   g++ $(LDFLAGS) -o $@ $^

$(OBJ_DIR)/%.o: $(SRC_DIR)/%.cpp
   g++ $(CPPFLAGS) $(CXXFLAGS) -c -o $@ $<

Automatic dependency graph generation

A "must" feature for most make systems. With GCC in can be done in a single pass as a side effect of the compilation by adding -MMD flag to CXXFLAGS and -include $(OBJ_FILES:.o=.d) to the end of the makefile body:

CXXFLAGS += -MMD
-include $(OBJ_FILES:.o=.d)

And as guys mentioned already, always have GNU Make Manual around, it is very helpful.

How do I display an alert dialog on Android?

showDialog(MainActivity.this, "title", "message", "OK", "Cancel", {...}, {...});

Kotlin

fun showDialog(context: Context, title: String, msg: String,
               positiveBtnText: String, negativeBtnText: String?,
               positiveBtnClickListener: DialogInterface.OnClickListener,
               negativeBtnClickListener: DialogInterface.OnClickListener?): AlertDialog {
    val builder = AlertDialog.Builder(context)
            .setTitle(title)
            .setMessage(msg)
            .setCancelable(true)
            .setPositiveButton(positiveBtnText, positiveBtnClickListener)
    if (negativeBtnText != null)
        builder.setNegativeButton(negativeBtnText, negativeBtnClickListener)
    val alert = builder.create()
    alert.show()
    return alert
}

Java

public static AlertDialog showDialog(@NonNull Context context, @NonNull String title, @NonNull String msg,
                                     @NonNull String positiveBtnText, @Nullable String negativeBtnText,
                                     @NonNull DialogInterface.OnClickListener positiveBtnClickListener,
                                     @Nullable DialogInterface.OnClickListener negativeBtnClickListener) {
    AlertDialog.Builder builder = new AlertDialog.Builder(context)
            .setTitle(title)
            .setMessage(msg)
            .setCancelable(true)
            .setPositiveButton(positiveBtnText, positiveBtnClickListener);
    if (negativeBtnText != null)
        builder.setNegativeButton(negativeBtnText, negativeBtnClickListener);
    AlertDialog alert = builder.create();
    alert.show();
    return alert;
}

lvalue required as left operand of assignment error when using C++

When you have an assignment operator in a statement, the LHS of the operator must be something the language calls an lvalue. If the LHS of the operator does not evaluate to an lvalue, the value from the RHS cannot be assigned to the LHS.

You cannot use:

10 = 20;

since 10 does not evaluate to an lvalue.

You can use:

int i;
i = 20;

since i does evaluate to an lvalue.

You cannot use:

int i;
i + 1 = 20;

since i + 1 does not evaluate to an lvalue.

In your case, p + 1 does not evaluate to an lavalue. Hence, you cannot use

p + 1 = p;

Object of custom type as dictionary key

You override __hash__ if you want special hash-semantics, and __cmp__ or __eq__ in order to make your class usable as a key. Objects who compare equal need to have the same hash value.

Python expects __hash__ to return an integer, returning Banana() is not recommended :)

User defined classes have __hash__ by default that calls id(self), as you noted.

There is some extra tips from the documentation.:

Classes which inherit a __hash__() method from a parent class but change the meaning of __cmp__() or __eq__() such that the hash value returned is no longer appropriate (e.g. by switching to a value-based concept of equality instead of the default identity based equality) can explicitly flag themselves as being unhashable by setting __hash__ = None in the class definition. Doing so means that not only will instances of the class raise an appropriate TypeError when a program attempts to retrieve their hash value, but they will also be correctly identified as unhashable when checking isinstance(obj, collections.Hashable) (unlike classes which define their own __hash__() to explicitly raise TypeError).

AngularJS : automatically detect change in model

In views with {{}} and/or ng-model, Angular is setting up $watch()es for you behind the scenes.

By default $watch compares by reference. If you set the third parameter to $watch to true, Angular will instead "shallow" watch the object for changes. For arrays this means comparing the array items, for object maps this means watching the properties. So this should do what you want:

$scope.$watch('myModel', function() { ... }, true);

Update: Angular v1.2 added a new method for this, `$watchCollection():

$scope.$watchCollection('myModel', function() { ... });

Note that the word "shallow" is used to describe the comparison rather than "deep" because references are not followed -- e.g., if the watched object contains a property value that is a reference to another object, that reference is not followed to compare the other object.

Could not load file or assembly 'System.Web.WebPages.Razor, Version=2.0.0.0

In ASP.NET MVC 4, the namespace is not System.Web.WebPages.Razor, but System.Web.Razor

That worked for me, change your web.config.

What is trunk, branch and tag in Subversion?

The answer by David Schmitt sums things up very well, but I think it is important to note that, to SVN, the terms 'branch', 'tag', and 'trunk' don't mean anything. These terms are purely semantic and only affect the way we, as users of the system, treat those directories. One could easily name them 'main', 'test', and 'releases.'; As long as everyone using the system understands how to use each section properly, it really doesn't matter what they're called.

In Java, how to find if first character in a string is upper case without regex

There is many ways to do that, but the simplest seems to be the following one:

boolean isUpperCase = Character.isUpperCase("My String".charAt(0));

select into in mysql

In MySQL, It should be like this

INSERT INTO this_table_archive (col1, col2, ..., coln)
SELECT col1, col2, ..., coln
FROM this_table
WHERE entry_date < '2011-01-01 00:00:00';

MySQL Documentation

Ubuntu: OpenJDK 8 - Unable to locate package

After adding the JDK repo, before Installing you might want to run an update first so the repo can be added run apt update

an then continue with your installation sudo apt install adoptopenjdk-8-hotspot

Error retrieving parent for item: No resource found that matches the given name '@android:style/TextAppearance.Holo.Widget.ActionBar.Title'

TextAppearance.Holo.Widget.ActionBar.Title appears to have been added in API Level 13. Make sure your build target is set to 13, not just 11.

Entityframework Join using join method and lambdas

Generally i prefer the lambda syntax with LINQ, but Join is one example where i prefer the query syntax - purely for readability.

Nonetheless, here is the equivalent of your above query (i think, untested):

var query = db.Categories         // source
   .Join(db.CategoryMaps,         // target
      c => c.CategoryId,          // FK
      cm => cm.ChildCategoryId,   // PK
      (c, cm) => new { Category = c, CategoryMaps = cm }) // project result
   .Select(x => x.Category);  // select result

You might have to fiddle with the projection depending on what you want to return, but that's the jist of it.

replace String with another in java

Try this: https://docs.oracle.com/javase/1.5.0/docs/api/java/lang/String.html#replace%28java.lang.CharSequence,%20java.lang.CharSequence%29

String a = "HelloBrother How are you!";
String r = a.replace("HelloBrother","Brother");

System.out.println(r);

This would print out "Brother How are you!"

Insert data into table with result from another select query

Below is an example of such a query:

INSERT INTO [93275].[93276].[93277].[93278] ( [Mobile Number], [Mobile Series], [Full Name], [Full Address], [Active Date], company ) IN 'I:\For Test\90-Mobile Series.accdb
SELECT [1].[Mobile Number], [1].[Mobile Series], [1].[Full Name], [1].[Full Address], [1].[Active Date], [1].[Company Name]
FROM 1
WHERE ((([1].[Mobile Series])="93275" Or ([1].[Mobile Series])="93276")) OR ((([1].[Mobile Series])="93277"));OR ((([1].[Mobile Series])="93278"));

PDO's query vs execute

Gilean's answer is great, but I just wanted to add that sometimes there are rare exceptions to best practices, and you might want to test your environment both ways to see what will work best.

In one case, I found that query worked faster for my purposes because I was bulk transferring trusted data from an Ubuntu Linux box running PHP7 with the poorly supported Microsoft ODBC driver for MS SQL Server.

I arrived at this question because I had a long running script for an ETL that I was trying to squeeze for speed. It seemed intuitive to me that query could be faster than prepare & execute because it was calling only one function instead of two. The parameter binding operation provides excellent protection, but it might be expensive and possibly avoided if unnecessary.

Given a couple rare conditions:

  1. If you can't reuse a prepared statement because it's not supported by the Microsoft ODBC driver.

  2. If you're not worried about sanitizing input and simple escaping is acceptable. This may be the case because binding certain datatypes isn't supported by the Microsoft ODBC driver.

  3. PDO::lastInsertId is not supported by the Microsoft ODBC driver.

Here's a method I used to test my environment, and hopefully you can replicate it or something better in yours:

To start, I've created a basic table in Microsoft SQL Server

CREATE TABLE performancetest (
    sid INT IDENTITY PRIMARY KEY,
    id INT,
    val VARCHAR(100)
);

And now a basic timed test for performance metrics.

$logs = [];

$test = function (String $type, Int $count = 3000) use ($pdo, &$logs) {
    $start = microtime(true);
    $i = 0;
    while ($i < $count) {
        $sql = "INSERT INTO performancetest (id, val) OUTPUT INSERTED.sid VALUES ($i,'value $i')";
        if ($type === 'query') {
            $smt = $pdo->query($sql);
        } else {
            $smt = $pdo->prepare($sql);
            $smt ->execute();
        }
        $sid = $smt->fetch(PDO::FETCH_ASSOC)['sid'];
        $i++;
    }
    $total = (microtime(true) - $start);
    $logs[$type] []= $total;
    echo "$total $type\n";
};

$trials = 15;
$i = 0;
while ($i < $trials) {
    if (random_int(0,1) === 0) {
        $test('query');
    } else {
        $test('prepare');
    }
    $i++;
}

foreach ($logs as $type => $log) {
    $total = 0;
    foreach ($log as $record) {
        $total += $record;
    }
    $count = count($log);
    echo "($count) $type Average: ".$total/$count.PHP_EOL;
}

I've played with multiple different trial and counts in my specific environment, and consistently get between 20-30% faster results with query than prepare/execute

5.8128969669342 prepare
5.8688418865204 prepare
4.2948560714722 query
4.9533629417419 query
5.9051351547241 prepare
4.332102060318 query
5.9672858715057 prepare
5.0667371749878 query
3.8260300159454 query
4.0791549682617 query
4.3775160312653 query
3.6910600662231 query
5.2708210945129 prepare
6.2671611309052 prepare
7.3791449069977 prepare
(7) prepare Average: 6.0673267160143
(8) query Average: 4.3276024162769

I'm curious to see how this test compares in other environments, like MySQL.

Android background music service

@Synxmax's answer is correct when using a Service and the MediaPlayer class, however you also need to declare the Service in the Manifest for this to work, like so:

<service
    android:enabled="true"
    android:name="com.package.name.BackgroundSoundService" />

How to print GETDATE() in SQL Server with milliseconds in time?

If your SQL Server version supports the function FORMAT you could do it like this:

select format(getdate(), 'yyyy-MM-dd HH:mm:ss.fff')

jQuery removeClass wildcard

The removeClass function takes a function argument since jQuery 1.4.

$("#hello").removeClass (function (index, className) {
    return (className.match (/(^|\s)color-\S+/g) || []).join(' ');
});

Live example: http://jsfiddle.net/xa9xS/1409/

Difference between getContext() , getApplicationContext() , getBaseContext() and "this"

getApplicationContext()

this is used for application level and refer to all activities.

getContext() and getBaseContext()

is most probably same .these are reffered only current activity which is live.

this

is refer current class object always.

Selecting pandas column by location

Two approaches that come to mind:

>>> df
          A         B         C         D
0  0.424634  1.716633  0.282734  2.086944
1 -1.325816  2.056277  2.583704 -0.776403
2  1.457809 -0.407279 -1.560583 -1.316246
3 -0.757134 -1.321025  1.325853 -2.513373
4  1.366180 -1.265185 -2.184617  0.881514
>>> df.iloc[:, 2]
0    0.282734
1    2.583704
2   -1.560583
3    1.325853
4   -2.184617
Name: C
>>> df[df.columns[2]]
0    0.282734
1    2.583704
2   -1.560583
3    1.325853
4   -2.184617
Name: C

Edit: The original answer suggested the use of df.ix[:,2] but this function is now deprecated. Users should switch to df.iloc[:,2].

How to enable PHP short tags?

As simple, as that, follow the following steps:

  1. Go to php.ini file
  2. Find short_open_tag and set it to on

    short_open_tag = On
    
  3. Restart the server

Java escape JSON String?

The best method would be using some JSON library, e.g. Jackson ( http://jackson.codehaus.org ).

But if this is not an option simply escape msget before adding it to your string:

The wrong way to do this is

String msgetEscaped = msget.replaceAll("\"", "\\\"");

Either use (as recommended in the comments)

String msgetEscaped = msget.replace("\"", "\\\"");

or

String msgetEscaped = msget.replaceAll("\"", "\\\\\"");

A sample with all three variants can be found here: http://ideone.com/Nt1XzO

How to correct indentation in IntelliJ

Ctrl + Alt + L works with Android Studio under xfce4 on Linux. I see that Gnome used to use this shortcut for lock screen, but in Gnome 3 it was changed to Super+L (AKA Windows+L): https://wiki.gnome.org/Design/OS/KeyboardShortcuts

Is there a way to select sibling nodes?

There are a few ways to do it.

Either one of the following should do the trick.

// METHOD A (ARRAY.FILTER, STRING.INDEXOF)
var siblings = function(node, children) {
    siblingList = children.filter(function(val) {
        return [node].indexOf(val) != -1;
    });
    return siblingList;
}

// METHOD B (FOR LOOP, IF STATEMENT, ARRAY.PUSH)
var siblings = function(node, children) {
    var siblingList = [];
    for (var n = children.length - 1; n >= 0; n--) {
        if (children[n] != node) {
            siblingList.push(children[n]);
        }  
    }
    return siblingList;
}

// METHOD C (STRING.INDEXOF, ARRAY.SPLICE)
var siblings = function(node, children) {
   siblingList = children;
   index = siblingList.indexOf(node);
   if(index != -1) {
       siblingList.splice(index, 1);
   }
   return siblingList;
}

FYI: The jQuery code-base is a great resource for observing Grade A Javascript.

Here is an excellent tool that reveals the jQuery code-base in a very streamlined way. http://james.padolsey.com/jquery/

How to use UIScrollView in Storyboard

In iOS7 I found that if I had a View inside a UIScrollView on a FreeForm-sized ViewController it would not scroll in the app, no matter what I did. I played around and found the following seemed to work, which uses no FreeForms:

  1. Insert a UIScrollView inside the main View of a ViewController

  2. Set the Autolayout constraints on the ScrollView as appropriate. For me I used 0 to Top Layout guide and 0 to Bottom layout Guide

  3. Inside the ScrollView, place a Container View. Set its height to whatever you want (e.g. 1000)

  4. Add a Height constraint (1000) to the Container so it doesn't resize. The bottom will be past the end of the form.

  5. Add the line [self.scrollView setContentSize:CGSizeMake(320, 1000)]; to the ViewController that contains the scrollView (which you've hooked up as a IBOutlet)

The ViewController (automatically added) that is associated with the Container will have the desired height (1000) in Interface Builder and will also scroll properly in the original view controller. You can now use the container's ViewController to layout your controls.

Explanation of polkitd Unregistered Authentication Agent

I found this problem too. Because centos service depend on multi-user.target for none desktop Cenots 7.2. so I delete multi-user.target from my .service file. It had missed.

Nested Recycler view height doesn't wrap its content

As @yigit mentioned, you need to override onMeasure(). Both @user2302510 and @DenisNek have good answers but if you want to support ItemDecoration you can use this custom layout manager.

And other answers cannot scroll when there are more items than can be displayed on the screen though. This one is using default implemantation of onMeasure() when there are more items than screen size.

public class MyLinearLayoutManager extends LinearLayoutManager {

public MyLinearLayoutManager(Context context, int orientation, boolean reverseLayout)    {
    super(context, orientation, reverseLayout);
}

private int[] mMeasuredDimension = new int[2];

@Override
public void onMeasure(RecyclerView.Recycler recycler, RecyclerView.State state,
                      int widthSpec, int heightSpec) {
    final int widthMode = View.MeasureSpec.getMode(widthSpec);
    final int heightMode = View.MeasureSpec.getMode(heightSpec);
    final int widthSize = View.MeasureSpec.getSize(widthSpec);
    final int heightSize = View.MeasureSpec.getSize(heightSpec);
    int width = 0;
    int height = 0;
    for (int i = 0; i < getItemCount(); i++) {
        measureScrapChild(recycler, i,
                View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                View.MeasureSpec.makeMeasureSpec(i, View.MeasureSpec.UNSPECIFIED),
                mMeasuredDimension);

        if (getOrientation() == HORIZONTAL) {
            width = width + mMeasuredDimension[0];
            if (i == 0) {
                height = mMeasuredDimension[1];
            }
        } else {
            height = height + mMeasuredDimension[1];
            if (i == 0) {
                width = mMeasuredDimension[0];
            }
        }
    }

    // If child view is more than screen size, there is no need to make it wrap content. We can use original onMeasure() so we can scroll view.
    if (height < heightSize && width < widthSize) {

        switch (widthMode) {
            case View.MeasureSpec.EXACTLY:
                width = widthSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        switch (heightMode) {
            case View.MeasureSpec.EXACTLY:
                height = heightSize;
            case View.MeasureSpec.AT_MOST:
            case View.MeasureSpec.UNSPECIFIED:
        }

        setMeasuredDimension(width, height);
    } else {
        super.onMeasure(recycler, state, widthSpec, heightSpec);
    }
}

private void measureScrapChild(RecyclerView.Recycler recycler, int position, int widthSpec,
                               int heightSpec, int[] measuredDimension) {

   View view = recycler.getViewForPosition(position);

   // For adding Item Decor Insets to view
   super.measureChildWithMargins(view, 0, 0);
    if (view != null) {
        RecyclerView.LayoutParams p = (RecyclerView.LayoutParams) view.getLayoutParams();
        int childWidthSpec = ViewGroup.getChildMeasureSpec(widthSpec,
                    getPaddingLeft() + getPaddingRight() + getDecoratedLeft(view) + getDecoratedRight(view), p.width);
            int childHeightSpec = ViewGroup.getChildMeasureSpec(heightSpec,
                    getPaddingTop() + getPaddingBottom() + getPaddingBottom() + getDecoratedBottom(view) , p.height);
            view.measure(childWidthSpec, childHeightSpec);

            // Get decorated measurements
            measuredDimension[0] = getDecoratedMeasuredWidth(view) + p.leftMargin + p.rightMargin;
            measuredDimension[1] = getDecoratedMeasuredHeight(view) + p.bottomMargin + p.topMargin;
            recycler.recycleView(view);
        }
    }
}

And if you want to use it with GridLayoutManager just extends it from GridLayoutManager and change

for (int i = 0; i < getItemCount(); i++)

to

for (int i = 0; i < getItemCount(); i = i + getSpanCount())

Setting the height of a DIV dynamically

Simplest I could come up...

function resizeResizeableHeight() {
    $('.resizableHeight').each( function() {
        $(this).outerHeight( $(this).parent().height() - ( $(this).offset().top - ( $(this).parent().offset().top + parseInt( $(this).parent().css('padding-top') ) ) ) )
    });
}

Now all you have to do is add the resizableHeight class to everything you want to autosize (to it's parent).

How does a ArrayList's contains() method evaluate objects?

It uses the equals method on the objects. So unless Thing overrides equals and uses the variables stored in the objects for comparison, it will not return true on the contains() method.

Print an integer in binary format in Java

Enter any decimal number as an input. After that we operations like modulo and division to convert the given input into binary number. Here is the source code of the Java Program to Convert Integer Values into Binary and the bits number of this binary for his decimal number. The Java program is successfully compiled and run on a Windows system. The program output is also shown below.

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int integer ;
        String binary = "";    //   here we count "" or null 
                               //   just String binary = null;
        System.out.print("Enter the binary Number: ");
        integer = sc.nextInt();

        while(integer>0)
        {
            int x = integer % 2;
            binary = x + binary;
            integer = integer / 2;  
        }
        System.out.println("Your binary number is : "+binary);
        System.out.println("your binary length : " + binary.length());
    }
}

MySQL Workbench not displaying query results

MySQL Workbench 6.3.4 fixes this issue. Custom builds are not needed anymore.

http://dev.mysql.com/downloads/workbench/

Is there possibility of sum of ArrayList without looping

Then write it yourself:

public int sum(List<Integer> list) {
     int sum = 0; 

     for (int i : list)
         sum = sum + i;

     return sum;
}

How to properly override clone method?

Do you absolutely have to use clone? Most people agree that Java's clone is broken.

Josh Bloch on Design - Copy Constructor versus Cloning

If you've read the item about cloning in my book, especially if you read between the lines, you will know that I think clone is deeply broken. [...] It's a shame that Cloneable is broken, but it happens.

You may read more discussion on the topic in his book Effective Java 2nd Edition, Item 11: Override clone judiciously. He recommends instead to use a copy constructor or copy factory.

He went on to write pages of pages on how, if you feel you must, you should implement clone. But he closed with this:

Is all this complexities really necessary? Rarely. If you extend a class that implements Cloneable, you have little choice but to implement a well-behaved clone method. Otherwise, you are better off providing alternative means of object copying, or simply not providing the capability.

The emphasis was his, not mine.


Since you made it clear that you have little choice but to implement clone, here's what you can do in this case: make sure that MyObject extends java.lang.Object implements java.lang.Cloneable. If that's the case, then you can guarantee that you will NEVER catch a CloneNotSupportedException. Throwing AssertionError as some have suggested seems reasonable, but you can also add a comment that explains why the catch block will never be entered in this particular case.


Alternatively, as others have also suggested, you can perhaps implement clone without calling super.clone.

Why can't I have abstract static methods in C#?

We actually override static methods (in delphi), it's a bit ugly, but it works just fine for our needs.

We use it so the classes can have a list of their available objects without the class instance, for example, we have a method that looks like this:

class function AvailableObjects: string; override;
begin
  Result := 'Object1, Object2';
end; 

It's ugly but necessary, this way we can instantiate just what is needed, instead of having all the classes instantianted just to search for the available objects.

This was a simple example, but the application itself is a client-server application which has all the classes available in just one server, and multiple different clients which might not need everything the server has and will never need an object instance.

So this is much easier to maintain than having one different server application for each client.

Hope the example was clear.

Password hash function for Excel VBA

Here's a module for calculating SHA1 hashes that is usable for Excel formulas eg. '=SHA1HASH("test")'. To use it, make a new module called 'module_sha1' and copy and paste it all in. This is based on some VBA code from http://vb.wikia.com/wiki/SHA-1.bas, with changes to support passing it a string, and executable from formulas in Excel cells.

' Based on: http://vb.wikia.com/wiki/SHA-1.bas
Option Explicit

Private Type FourBytes
    A As Byte
    B As Byte
    C As Byte
    D As Byte
End Type
Private Type OneLong
    L As Long
End Type

Function HexDefaultSHA1(Message() As Byte) As String
 Dim H1 As Long, H2 As Long, H3 As Long, H4 As Long, H5 As Long
 DefaultSHA1 Message, H1, H2, H3, H4, H5
 HexDefaultSHA1 = DecToHex5(H1, H2, H3, H4, H5)
End Function

Function HexSHA1(Message() As Byte, ByVal Key1 As Long, ByVal Key2 As Long, ByVal Key3 As Long, ByVal Key4 As Long) As String
 Dim H1 As Long, H2 As Long, H3 As Long, H4 As Long, H5 As Long
 xSHA1 Message, Key1, Key2, Key3, Key4, H1, H2, H3, H4, H5
 HexSHA1 = DecToHex5(H1, H2, H3, H4, H5)
End Function

Sub DefaultSHA1(Message() As Byte, H1 As Long, H2 As Long, H3 As Long, H4 As Long, H5 As Long)
 xSHA1 Message, &H5A827999, &H6ED9EBA1, &H8F1BBCDC, &HCA62C1D6, H1, H2, H3, H4, H5
End Sub

Sub xSHA1(Message() As Byte, ByVal Key1 As Long, ByVal Key2 As Long, ByVal Key3 As Long, ByVal Key4 As Long, H1 As Long, H2 As Long, H3 As Long, H4 As Long, H5 As Long)
 'CA62C1D68F1BBCDC6ED9EBA15A827999 + "abc" = "A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D"
 '"abc" = "A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D"

 Dim U As Long, P As Long
 Dim FB As FourBytes, OL As OneLong
 Dim i As Integer
 Dim W(80) As Long
 Dim A As Long, B As Long, C As Long, D As Long, E As Long
 Dim T As Long

 H1 = &H67452301: H2 = &HEFCDAB89: H3 = &H98BADCFE: H4 = &H10325476: H5 = &HC3D2E1F0

 U = UBound(Message) + 1: OL.L = U32ShiftLeft3(U): A = U \ &H20000000: LSet FB = OL 'U32ShiftRight29(U)

 ReDim Preserve Message(0 To (U + 8 And -64) + 63)
 Message(U) = 128

 U = UBound(Message)
 Message(U - 4) = A
 Message(U - 3) = FB.D
 Message(U - 2) = FB.C
 Message(U - 1) = FB.B
 Message(U) = FB.A

 While P < U
     For i = 0 To 15
         FB.D = Message(P)
         FB.C = Message(P + 1)
         FB.B = Message(P + 2)
         FB.A = Message(P + 3)
         LSet OL = FB
         W(i) = OL.L
         P = P + 4
     Next i

     For i = 16 To 79
         W(i) = U32RotateLeft1(W(i - 3) Xor W(i - 8) Xor W(i - 14) Xor W(i - 16))
     Next i

     A = H1: B = H2: C = H3: D = H4: E = H5

     For i = 0 To 19
         T = U32Add(U32Add(U32Add(U32Add(U32RotateLeft5(A), E), W(i)), Key1), ((B And C) Or ((Not B) And D)))
         E = D: D = C: C = U32RotateLeft30(B): B = A: A = T
     Next i
     For i = 20 To 39
         T = U32Add(U32Add(U32Add(U32Add(U32RotateLeft5(A), E), W(i)), Key2), (B Xor C Xor D))
         E = D: D = C: C = U32RotateLeft30(B): B = A: A = T
     Next i
     For i = 40 To 59
         T = U32Add(U32Add(U32Add(U32Add(U32RotateLeft5(A), E), W(i)), Key3), ((B And C) Or (B And D) Or (C And D)))
         E = D: D = C: C = U32RotateLeft30(B): B = A: A = T
     Next i
     For i = 60 To 79
         T = U32Add(U32Add(U32Add(U32Add(U32RotateLeft5(A), E), W(i)), Key4), (B Xor C Xor D))
         E = D: D = C: C = U32RotateLeft30(B): B = A: A = T
     Next i

     H1 = U32Add(H1, A): H2 = U32Add(H2, B): H3 = U32Add(H3, C): H4 = U32Add(H4, D): H5 = U32Add(H5, E)
 Wend
End Sub

Function U32Add(ByVal A As Long, ByVal B As Long) As Long
 If (A Xor B) < 0 Then
     U32Add = A + B
 Else
     U32Add = (A Xor &H80000000) + B Xor &H80000000
 End If
End Function

Function U32ShiftLeft3(ByVal A As Long) As Long
 U32ShiftLeft3 = (A And &HFFFFFFF) * 8
 If A And &H10000000 Then U32ShiftLeft3 = U32ShiftLeft3 Or &H80000000
End Function

Function U32ShiftRight29(ByVal A As Long) As Long
 U32ShiftRight29 = (A And &HE0000000) \ &H20000000 And 7
End Function

Function U32RotateLeft1(ByVal A As Long) As Long
 U32RotateLeft1 = (A And &H3FFFFFFF) * 2
 If A And &H40000000 Then U32RotateLeft1 = U32RotateLeft1 Or &H80000000
 If A And &H80000000 Then U32RotateLeft1 = U32RotateLeft1 Or 1
End Function
Function U32RotateLeft5(ByVal A As Long) As Long
 U32RotateLeft5 = (A And &H3FFFFFF) * 32 Or (A And &HF8000000) \ &H8000000 And 31
 If A And &H4000000 Then U32RotateLeft5 = U32RotateLeft5 Or &H80000000
End Function
Function U32RotateLeft30(ByVal A As Long) As Long
 U32RotateLeft30 = (A And 1) * &H40000000 Or (A And &HFFFC) \ 4 And &H3FFFFFFF
 If A And 2 Then U32RotateLeft30 = U32RotateLeft30 Or &H80000000
End Function

Function DecToHex5(ByVal H1 As Long, ByVal H2 As Long, ByVal H3 As Long, ByVal H4 As Long, ByVal H5 As Long) As String
 Dim H As String, L As Long
 DecToHex5 = "00000000 00000000 00000000 00000000 00000000"
 H = Hex(H1): L = Len(H): Mid(DecToHex5, 9 - L, L) = H
 H = Hex(H2): L = Len(H): Mid(DecToHex5, 18 - L, L) = H
 H = Hex(H3): L = Len(H): Mid(DecToHex5, 27 - L, L) = H
 H = Hex(H4): L = Len(H): Mid(DecToHex5, 36 - L, L) = H
 H = Hex(H5): L = Len(H): Mid(DecToHex5, 45 - L, L) = H
End Function

' Convert the string into bytes so we can use the above functions
' From Chris Hulbert: http://splinter.com.au/blog

Public Function SHA1HASH(str)
  Dim i As Integer
  Dim arr() As Byte
  ReDim arr(0 To Len(str) - 1) As Byte
  For i = 0 To Len(str) - 1
   arr(i) = Asc(Mid(str, i + 1, 1))
  Next i
  SHA1HASH = Replace(LCase(HexDefaultSHA1(arr)), " ", "")
End Function

Use Ant for running program with command line arguments

The only effective mechanism for passing parameters into a build is to use Java properties:

ant -Done=1 -Dtwo=2

The following example demonstrates how you can check and ensure the expected parameters have been passed into the script

<project name="check" default="build">

    <condition property="params.set">
        <and>
            <isset property="one"/>
            <isset property="two"/>
        </and>
    </condition>

    <target name="check">
        <fail unless="params.set">
        Must specify the parameters: one, two
        </fail>
    </target>

    <target name="build" depends="check">
        <echo>
        one = ${one}
        two = ${two}
        </echo>
    </target>

</project>

What are the possible values of the Hibernate hbm2ddl.auto configuration and what do they do

First, the possible values for the hbm2ddl configuration property are the following ones:

  • none - No action is performed. The schema will not be generated.
  • create-only - The database schema will be generated.
  • drop - The database schema will be dropped.
  • create - The database schema will be dropped and created afterward.
  • create-drop - The database schema will be dropped and created afterward. Upon closing the SessionFactory, the database schema will be dropped.
  • validate - The database schema will be validated using the entity mappings.
  • update - The database schema will be updated by comparing the existing database schema with the entity mappings.

The hibernate.hbm2ddl.auto="update" is convenient but less flexible if you plan on adding functions or executing some custom scripts.

So, The most flexible approach is to use Flyway.

However, even if you use Flyway, you can still generate the initial migration script using hbm2ddl.

ReactJS: Warning: setState(...): Cannot update during an existing state transition

THE PROBLEM is here: onClick={this.handleButtonChange(false)}

When you pass this.handleButtonChange(false) to onClick, you are actually calling the function with value = false and setting onClick to the function's return value, which is undefined. Also, calling this.handleButtonChange(false) then calls this.setState() which triggers a re-render, resulting in an infinite render loop.

THE SOLUTION is to pass the function in a lambda: onClick={() => this.handleButtonChange(false)}. Here you are setting onClick to equal a function that will call handleButtonChange(false) when the button is clicked.

The below example may help:

function handleButtonChange(value){
  console.log("State updated!")
}

console.log(handleButtonChange(false))
//output: State updated!
//output: undefined

console.log(() => handleButtonChange(false))
//output: ()=>{handleButtonChange(false);}

Python 3 sort a dict by its values

You can sort by values in reverse order (largest to smallest) using a dictionary comprehension:

{k: d[k] for k in sorted(d, key=d.get, reverse=True)}
# {'b': 4, 'a': 3, 'c': 2, 'd': 1}

If you want to sort by values in ascending order (smallest to largest)

{k: d[k] for k in sorted(d, key=d.get)}
# {'d': 1, 'c': 2, 'a': 3, 'b': 4}

If you want to sort by the keys in ascending order

{k: d[k] for k in sorted(d)}
# {'a': 3, 'b': 4, 'c': 2, 'd': 1}

This works on CPython 3.6+ and any implementation of Python 3.7+ because dictionaries keep insertion order.

#define in Java

static final int PROTEINS = 1
...
myArray[PROTEINS]

You'd normally put "constants" in the class itself. And do note that a compiler is allowed to optimize references to it away, so don't change it unless you recompile all the using classes.

class Foo {
  public static final int SIZE = 5;

  public static int[] arr = new int[SIZE];
}
class Bar {
  int last = arr[Foo.SIZE - 1]; 
}

Edit cycle... SIZE=4. Also compile Bar because you compiler may have just written "4" in the last compilation cycle!

Select Top and Last rows in a table (SQL server)

You must sort your data according your needs (es. in reverse order) and use select top query

Reflection - get attribute name and value on property

private static Dictionary<string, string> GetAuthors()
{
    return typeof(Book).GetProperties()
        .SelectMany(prop => prop.GetCustomAttributes())
        .OfType<AuthorAttribute>()
        .ToDictionary(a => a.GetType().Name.Replace("Attribute", ""), a => a.Name);
}

Example using generics (target framework 4.5)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

private static Dictionary<string, string> GetAttribute<TAttribute, TType>(
    Func<TAttribute, string> valueFunc)
    where TAttribute : Attribute
{
    return typeof(TType).GetProperties()
        .SelectMany(p => p.GetCustomAttributes())
        .OfType<TAttribute>()
        .ToDictionary(a => a.GetType().Name.Replace("Attribute", ""), valueFunc);
}

Usage

var dictionary = GetAttribute<AuthorAttribute, Book>(a => a.Name);

"Strict Standards: Only variables should be passed by reference" error

array_shift the only parameter is an array passed by reference. The return value of explode(".", $value) does not have any reference. Hence the error.

You should store the return value to a variable first.

    $arr = explode(".", $value);
    $extension = strtolower(array_pop($arr));   
    $fileName = array_shift($arr);

From PHP.net

The following things can be passed by reference:

- Variables, i.e. foo($a)
- New statements, i.e. foo(new foobar())
- [References returned from functions][2]

No other expressions should be passed by reference, as the result is undefined. For example, the following examples of passing by reference are invalid:

How to check if activity is in foreground or in visible background?

If you use finish() just to avoid new app to starts in the stack (task) of you app, you can use Intent.FLAG_ACTIVITY_NEW_TASK flag, when starting new application and do not call finish() at all. According to the documentation, this is the flag to be used to implement a "launcher" style behavior.

// just add this line before you start an activity
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(intent);

How to find when a web page was last updated

For checking the Last Modified header, you can use httpie (docs).

Installation

pip install httpie --user

Usage

$ http -h https://martin-thoma.com/author/martin-thoma/ | grep 'Last-Modified\|Date'
Date: Fri, 06 Jan 2017 10:06:43 GMT
Last-Modified: Fri, 06 Jan 2017 07:42:34 GMT

The Date is important as this reports the server time, not your local time. Also, not every server sends Last-Modified (e.g. superuser seems not to do it).

How to pause javascript code execution for 2 seconds

This Link might be helpful for you.

Every time I've wanted a sleep in the middle of my function, I refactored to use a setTimeout().

How to atomically delete keys matching a pattern using Redis

Execute in bash:

redis-cli KEYS "prefix:*" | xargs redis-cli DEL

UPDATE

Ok, i understood. What about this way: store current additional incremental prefix and add it to all your keys. For example:

You have values like this:

prefix_prefix_actuall = 2
prefix:2:1 = 4
prefix:2:2 = 10

When you need to purge data, you change prefix_actuall first (for example set prefix_prefix_actuall = 3), so your application will write new data to keys prefix:3:1 and prefix:3:2. Then you can safely take old values from prefix:2:1 and prefix:2:2 and purge old keys.

What is stdClass in PHP?

Its also worth noting that by using Casting you do not actually need to create an object as in the answer given by @Bandula. Instead you can simply cast your array to an object and the stdClass is returned. For example:

$array = array(
    'Property1'=>'hello',
    'Property2'=>'world',
    'Property3'=>'again',
);

$obj = (object) $array;
echo $obj->Property3;

Output: again

SQL time difference between two dates result in hh:mm:ss

I came across this post today as I was trying to gather the time difference between fields located in separate tables joined together on a key field. This is the working code for such an endeavor. (tested in sql 2010) Bare in mind that my original query co-joined 6 tables on a common keyfield, in the code below I have removed the other tables as to not cause any confusion for the reader.

The purpose of the query is to calculate the difference between the variables CreatedUTC & BackupUTC, where difference is expressed in days and the field is called 'DaysActive.'

declare @CreatedUTC datetime
declare @BackupUtc datetime


SELECT TOP 500

table02.Column_CreatedUTC AS DeviceCreated,
CAST(DATEDIFF(day, table02.Column_CreatedUTC, table03.Column_EndDateUTC) AS nvarchar(5))+ ' Days' As DaysActive,
table03.Column_EndDateUTC AS LastCompleteBackup

FROM

Operations.table01 AS table01

LEFT OUTER JOIN

    dbo.table02 AS table02
ON
    table02.Column_KeyField = table01.Column_KeyField

LEFT OUTER JOIN 

    dbo.table03 AS table03
ON
    table01.Column_KeyField = table03.Column_KeyField

Where table03.Column_EndDateUTC > dateadd(hour, -24, getutcdate()) --Gathers records with an end date in the last 24 hours
AND table02.[Column_CreatedUTC] = COALESCE(@CreatedUTC, table02.[Column_CreatedUTC])
AND table03.[Column_EndDateUTC] = COALESCE(@BackupUTC, table03.[Column_EndDateUTC])

GROUP BY table03.Column_EndDateUTC, table02.Column_CreatedUTC
ORDER BY table02.Column_CreatedUTC ASC, DaysActive, table03.Column_EndDateUTC DESC

The Output will be as follows:

[DeviceCreated]..[DaysActive]..[LastCompleteBackup]
---------------------------------------------------------
[2/13/12 16:04]..[463 Days]....[5/21/13 12:14]
[2/12/13 22:37]..[97 Days].....[5/20/13 22:10]

Show and hide a View with a slide up/down animation

You can start the correct Animation when the visibility of the LinearLayout changes by creating a new subclass of LinearLayout and overriding setVisibility() to start the Animations. Consider something like this:

public class SimpleViewAnimator extends LinearLayout
{
    private Animation inAnimation;
    private Animation outAnimation;

    public SimpleViewAnimator(Context context)
    {
        super(context);
    }

    public void setInAnimation(Animation inAnimation)
    {
        this.inAnimation = inAnimation;
    }

    public void setOutAnimation(Animation outAnimation)
    {
        this.outAnimation = outAnimation;
    }

    @Override
    public void setVisibility(int visibility)
    {
        if (getVisibility() != visibility)
        {
            if (visibility == VISIBLE)
            {
                if (inAnimation != null) startAnimation(inAnimation);
            }
            else if ((visibility == INVISIBLE) || (visibility == GONE))
            {
                if (outAnimation != null) startAnimation(outAnimation);
            }
        }

        super.setVisibility(visibility);
    }
}

What's the difference between HEAD, working tree and index, in Git?

A few other good references on those topics:

workflow

I use the index as a checkpoint.

When I'm about to make a change that might go awry — when I want to explore some direction that I'm not sure if I can follow through on or even whether it's a good idea, such as a conceptually demanding refactoring or changing a representation type — I checkpoint my work into the index.

If this is the first change I've made since my last commit, then I can use the local repository as a checkpoint, but often I've got one conceptual change that I'm implementing as a set of little steps.
I want to checkpoint after each step, but save the commit until I've gotten back to working, tested code.

Notes:

  1. the workspace is the directory tree of (source) files that you see and edit.

  2. The index is a single, large, binary file in <baseOfRepo>/.git/index, which lists all files in the current branch, their sha1 checksums, time stamps and the file name -- it is not another directory with a copy of files in it.

  3. The local repository is a hidden directory (.git) including an objects directory containing all versions of every file in the repo (local branches and copies of remote branches) as a compressed "blob" file.

Don't think of the four 'disks' represented in the image above as separate copies of the repo files.

3 states

They are basically named references for Git commits. There are two major types of refs: tags and heads.

  • Tags are fixed references that mark a specific point in history, for example v2.6.29.
  • On the contrary, heads are always moved to reflect the current position of project development.

commits

(note: as commented by Timo Huovinen, those arrows are not what the commits point to, it's the workflow order, basically showing arrows as 1 -> 2 -> 3 -> 4 where 1 is the first commit and 4 is the last)

Now we know what is happening in the project.
But to know what is happening right here, right now there is a special reference called HEAD. It serves two major purposes:

  • it tells Git which commit to take files from when you checkout, and
  • it tells Git where to put new commits when you commit.

When you run git checkout ref it points HEAD to the ref you’ve designated and extracts files from it. When you run git commit it creates a new commit object, which becomes a child of current HEAD. Normally HEAD points to one of the heads, so everything works out just fine.

checkout

.htaccess redirect all pages to new domain

Use conditional redirects with Options -FollowSymLinks and AllowOverride -Options disabled by the Hoster if a few local files should be served too:

Sample .htaccess

# Redirect everything except index.html to http://foo
<FilesMatch "(?<!index\.html)$">
    Redirect 301 / http://foo/
</FilesMatch>

This example will serve local index.html and redirects all other staff to new domain.

How do relative file paths work in Eclipse?

Yeah, eclipse sees the top directory as the working/root directory, for the purposes of paths.

...just thought I'd add some extra info. I'm new here! I'd like to help.

SQL Server : check if variable is Empty or NULL for WHERE clause

Just use

If @searchType is null means 'return the whole table' then use

WHERE p.[Type] = @SearchType OR @SearchType is NULL

If @searchType is an empty string means 'return the whole table' then use

WHERE p.[Type] = @SearchType OR @SearchType = ''

If @searchType is null or an empty string means 'return the whole table' then use

WHERE p.[Type] = @SearchType OR Coalesce(@SearchType,'') = ''

Correct Semantic tag for copyright info - html5

In a link, if you put rel=license it: Indicates that the main content of the current document is covered by the copyright license described by the referenced document. Source: http://www.w3.org/wiki/HTML/Elements/link

So, for example, <a rel="license" href="https://creativecommons.org/licenses/by/4.0/">Copyrighted but you can use what's here as long as you credit me</a> gives a human something to read and lets computers know that the rest of the page is licensed under the CC BY 4.0 license.

What methods of ‘clearfix’ can I use?

A clearfix is a way for an element to automatically clear after itself, so that you don't need to add additional markup.

.clearfix:after {
   content: " "; /* Older browser do not support empty content */
   visibility: hidden;
   display: block;
   height: 0;
   clear: both;
}
.cleaner {
  clear: both;
}

Normally you would need to do something as follows:

<div style="float: left;">Sidebar</div>
<div class="cleaner"></div> <!-- Clear the float -->

With clearfix, you only need to

<div style="float: left;" class="clearfix">Sidebar</div>
<!-- No Clearing div! -->

Python if-else short-hand

Try this:

x = a > b and 10 or 11

This is a sample of execution:

>>> a,b=5,7
>>> x = a > b and 10 or 11
>>> print x
11

phpMyAdmin Error: The mbstring extension is missing. Please check your PHP configuration

this ones solved my problem

1.open command prompt in administration

  1. then open apache bin folder like this,

    c:\ cd wamp\bin\apache\apache2.4.17\bin>

  2. then type after the above

    c:\ cd wamp\bin\apache\apache2.4.17\bin> mklink php.ini d:\wamp\bin\php\php5.6.15\phpForApache.ini

  3. thats it close the command prompt and restart the wamp and open it in admin mode.

  4. original post : PHP: No php.ini file thanks to xiao.

Add object to ArrayList at specified index

You could also override ArrayList to insert nulls between your size and the element you want to add.

import java.util.ArrayList;


public class ArrayListAnySize<E> extends ArrayList<E>{
    @Override
    public void add(int index, E element){
        if(index >= 0 && index <= size()){
            super.add(index, element);
            return;
        }
        int insertNulls = index - size();
        for(int i = 0; i < insertNulls; i++){
            super.add(null);
        }
        super.add(element);
    }
}

Then you can add at any point in the ArrayList. For example, this main method:

public static void main(String[] args){
    ArrayListAnySize<String> a = new ArrayListAnySize<>();
    a.add("zero");
    a.add("one");
    a.add("two");
    a.add(5,"five");
    for(int i = 0; i < a.size(); i++){
        System.out.println(i+": "+a.get(i));
    }
}   

yields this result from the console:

0: zero

1: one

2: two

3: null

4: null

5: five

Align text in JLabel to the right

This can be done in two ways.

JLabel Horizontal Alignment

You can use the JLabel constructor:

JLabel(String text, int horizontalAlignment) 

To align to the right:

JLabel label = new JLabel("Telephone", SwingConstants.RIGHT);

JLabel also has setHorizontalAlignment:

label.setHorizontalAlignment(SwingConstants.RIGHT);

This assumes the component takes up the whole width in the container.

Using Layout

A different approach is to use the layout to actually align the component to the right, whilst ensuring they do not take the whole width. Here is an example with BoxLayout:

    Box box = Box.createVerticalBox();
    JLabel label1 = new JLabel("test1, the beginning");
    label1.setAlignmentX(Component.RIGHT_ALIGNMENT);
    box.add(label1);

    JLabel label2 = new JLabel("test2, some more");
    label2.setAlignmentX(Component.RIGHT_ALIGNMENT);
    box.add(label2);

    JLabel label3 = new JLabel("test3");
    label3.setAlignmentX(Component.RIGHT_ALIGNMENT);
    box.add(label3);


    add(box);

Better way to generate array of all letters in the alphabet

Simplicity is a virtue. Use this naturally readable array:

char alphabet[] = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};

Common CSS Media Queries Break Points

Keep your code clean and stylesheets logically separated per screen 'media' type config...


1) Using himansu's answer from above as a reference: Common CSS Media Queries Break Points
AND
2) https://www.w3schools.com/css/css3_mediaqueries.asp

your answer would be:

<link rel="stylesheet" media="@media only screen and (min-width : 320px) and (max-width : 480px)" href="mobilePortrait.css">

<link rel="stylesheet" media="@media only screen and (min-width : 481px) and (max-width : 595px)" href="mobileLandscape.css">

How to convert an Image to base64 string in java?

I think you might want:

String encodedFile = Base64.getEncoder().encodeToString(bytes);

Warning about SSL connection when connecting to MySQL database

Mention the url like:

jdbc:mysql://hostname:3306/hibernatedb?autoReconnect=true&useSSL=false

But in xml configuration when you mention & sign, the IDE shows below error:

The reference to entity "useSSL" must end with the ';' delimiter.

And then you have to explicitly use the &amp; instead of & to be determined as & by xml thereafter in xml you have to give the url in xml configuration like this:

<property name="connection.url">jdbc:mysql://hostname:3306/hibernatedb?autoReconnect=true&amp;useSSL=false</property>

How to use find command to find all files with extensions from list?

find -E /path/to -regex ".*\.(jpg|gif|png|jpeg)" > log

The -E saves you from having to escape the parens and pipes in your regex.

UITextView that expands to text using auto layout

BTW, I built an expanding UITextView using a subclass and overriding intrinsic content size. I discovered a bug in UITextView that you might want to investigate in your own implementation. Here is the problem:

The expanding text view would grow down to accommodate the growing text if you type single letters at a time. But if you paste a bunch of text into it, it would not grow down but the text would scroll up and the text at the top was out of view.

The solution: Override setBounds: in your subclass. For some unknown reason, the pasting caused the bounds.origin.y value to be non-zee (33 in every case that I saw). So I overrode setBounds: to always set the bounds.origin.y to zero. Fixed the problem.

How to detect idle time in JavaScript elegantly?

Here is a rough jQuery implementation of tvanfosson's idea:

$(document).ready(function(){

   idleTime = 0;

   //Increment the idle time counter every second.
   var idleInterval = setInterval(timerIncrement, 1000);

   function timerIncrement()
   {
     idleTime++;
     if (idleTime > 2)
     {
       doPreload();
     }
   }

   //Zero the idle timer on mouse movement.
   $(this).mousemove(function(e){
      idleTime = 0;
   });

   function doPreload()
   {
     //Preload images, etc.
   }

})

Sum all values in every column of a data.frame in R

For the sake of completion:

 apply(people[,-1], 2, function(x) sum(x))
#Height Weight 
#   199    425 

How To Get Selected Value From UIPickerView

Getting the selected title of a picker:

let component = 0
let row = picker.selectedRow(inComponent: component)
let title = picker.delegate?.pickerView?(picker, titleForRow: row, forComponent: component)

Android: How to Enable/Disable Wifi or Internet Connection Programmatically

This method is deprecated now from now starting with Android Q.

Try This will really help.

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.Q) {// if build version is less than Q try the old traditional method
                    if (!wifiManager.isWifiEnabled()) {
                        wifiManager.setWifiEnabled(true);
                        btnOnOff.setText("Wifi ONN");
                    } else {
                        wifiManager.setWifiEnabled(false);
                        btnOnOff.setText("Wifi OFF");
                    }
                } else {// if it is Android Q and above go for the newer way    NOTE: You can also use this code for less than android Q also
                    Intent panelIntent = new Intent(Settings.Panel.ACTION_WIFI);
                    startActivityForResult(panelIntent, 1);
                }

Program to find largest and smallest among 5 numbers without using array

Here's my implementation: Simple and short

#include <iostream>
#include <cstdio>
using namespace std;


int max_of_five(int a, int b, int c, int d,int e){
    int large= max(max(a, b), max(c,d));
    return max(large,e);

}

int min_of_five(int a,int b,int c, int d,int e){
    int small=min(min(a,b),min(c,d));
    return min(small,e);
}


int main() {
    int a, b, c, d,e;

    scanf("%d %d %d %d %d", &a, &b, &c, &d,&e);
    int ans = max_of_five(a, b, c, d, e);
    int ans1=min_of_five(a,b,c,d,e);
    printf("Max:\t%d\n", ans);
    printf("Min:\t%d", ans1);

    return 0;
}

What is the difference between Double.parseDouble(String) and Double.valueOf(String)?

They both convert a String to a double value but wherease the parseDouble() method returns the primitive double value, the valueOf() method further converts the primitive double to a Double wrapper class object which contains the primitive double value.

The conversion from String to primitive double may throw NFE(NumberFormatException) if the value in String is not convertible into a primitive double.

center aligning a fixed position div

Center it horizontally:

display: fixed;
top: 0; 
left: 0;
transform: translate(calc(50vw - 50%));

Center it horizontally and vertically:

display: fixed;
top: 0; 
left: 0;
transform: translate(calc(50vw - 50%), calc(50vh - 50%));

No side effect: It will not limit element's width when using margins in flexbox

Solution for "Fatal error: Maximum function nesting level of '100' reached, aborting!" in PHP

I had this issue with WordPress on cloud9. It turns out it was the W3 Caching plugin. I disabled the plugin and it worked fine.

How do you view ALL text from an ntext or nvarchar(max) in SSMS?

Return data as XML

SELECT CONVERT(XML, [Data]) AS [Value]
FROM [dbo].[FormData]
WHERE [UID] LIKE '{my-uid}'

Make sure you set a reasonable limit in the SSMS options window, depending on the result you're expecting. enter image description here

This will work if the text you're returning doesn't contain unencoded characters like & instead of &amp; that will cause the XML conversion to fail.

Returning data using PowerShell

For this you will need the PowerShell SQL Server module installed on the machine on which you'll be running the command.

If you're all set up, configure and run the following script:

Invoke-Sqlcmd -Query "SELECT [Data] FROM [dbo].[FormData] WHERE [UID] LIKE '{my-uid}'" -ServerInstance "database-server-name" -Database "database-name" -Username "user" -Password "password" -MaxCharLength 10000000 | Out-File -filePath "C:\db_data.txt"

Make sure you set the -MaxCharLength parameter to a value that suits your needs.

Reading InputStream as UTF-8

I ran into the same problem every time it finds a special character marks it as ??. to solve this, I tried using the encoding: ISO-8859-1

BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream("txtPath"),"ISO-8859-1"));

while ((line = br.readLine()) != null) {

}

I hope this can help anyone who sees this post.

Android Studio marks R in red with error message "cannot resolve symbol R", but build succeeds

I get bitten by this every now and then and there's another thing to try: match your compileSdk and buildSdk versions to the latest available.

I had changed my compileSdkVersion from 21 back to 19 because the Android Studio (1.1 canary channel) debugger was not tracing properly into prebuilt libraries. I found that it seemed to be tracing based on the buildToolsVersion (19.1.0), which I verified by clicking an error in the stack trace (and then choosing 19 instead of 21). Though I changed it directly in the build.gradle file, a graphical walkthrough is here: https://www.blogger.com/comment.g?blogID=4722727826918942842&postID=3875998513888772255 and I'll summarize:

  1. Android Studio IDE, select File | Project Structure.
  2. Choose your module, like "app"
  3. In Compile SDK field, choose the latest version
  4. Also choose the latest version in Build Tools

Confirm, and the project should automatically sync properly.

The lesson I'm getting from this is that they should both be the same.

Failed to install android-sdk: "java.lang.NoClassDefFoundError: javax/xml/bind/annotation/XmlSchema"

As @steven pointed out, install Java 8 (here a link for Ubuntu 16.04, 18.04 and 20.04/20.10 https://computingforgeeks.com/how-to-install-java-8-on-ubuntu/) and then set it as the default Java version with this command:

sudo update-alternatives --config java

CSS3 Transform Skew One Side

I know this is old, but I would like to suggest using a linear-gradient to achieve the same effect instead of margin offset. This is will maintain any content at its original place.

http://jsfiddle.net/zwXaf/2/

HTML

<ul>
    <li><a href="#">One</a></li>
    <li><a href="#">Two</a></li>
    <li><a href="#">Three</a></li>
</ul>

CSS

/* reset */
ul, li, a {
    margin: 0; padding: 0;
}
/* nav stuff */
ul, li, a {
    display: inline-block;
    text-align: center;
}
/* appearance styling */
ul {
    /* hacks to make one side slant only */
    overflow: hidden;
    background: linear-gradient(to right, red, white, white, red);
}
li {
    background-color: red;
     transform:skewX(-20deg);
    -ms-transform:skewX(-20deg);
    -webkit-transform:skewX(-20deg);
}
li a {
    padding: 3px 6px 3px 6px;
    color: #ffffff;
    text-decoration: none;
    width: 80px;
     transform:skewX(20deg);
    -ms-transform:skewX(20deg);
    -webkit-transform:skewX(20deg);
}

How do I format my oracle queries so the columns don't wrap?

Never mind, figured it out:

set wrap off
set linesize 3000 -- (or to a sufficiently large value to hold your results page)

Which I found by:

show all

And looking for some option that seemed relevant.

Laravel Advanced Wheres how to pass variable into function?

You can pass the necessary variables from the parent scope into the closure with the use keyword.

For example:

DB::table('users')->where(function ($query) use ($activated) {
    $query->where('activated', '=', $activated);
})->get();

More on that here.

EDIT (2019 update):

PHP 7.4 (will be released at November 28, 2019) introduces a shorter variation of the anonymous functions called arrow functions which makes this a bit less verbose.

An example using PHP 7.4 which is functionally nearly equivalent (see the 3rd bullet point below):

DB::table('users')->where(fn($query) => $query->where('activated', '=', $activated))->get();

Differences compared to the regular syntax:

  • fn keyword instead of function.
  • No need to explicitly list all variables which should be captured from the parent scope - this is now done automatically by-value. See the lack of use keyword in the latter example.
  • Arrow functions always return a value. This also means that it's impossible to use void return type when declaring them.
  • The return keyword must be omitted.
  • Arrow functions must have a single expression which is the return statement. Multi-line functions aren't supported at the moment. You can still chain methods though.

Dark Theme for Visual Studio 2010 With Productivity Power Tools

  1. Install the Visual Studio Color Theme Editor extension:
  2. Make your own color scheme or try: The Dark Expression Blend Color Theme (preview below)
  3. Once you have that, you'll want schemes for the text editor as well. This site has several, including the VS2012 "dark" theme implemented for VS2010.

Visual Studio 2010 with Dark Theme

How can I show an element that has display: none in a CSS rule?

Because setting the div's display style property to "" doesn't change anything in the CSS rule itself. That basically just creates an "empty," inline CSS rule, which has no effect beyond clearing the same property on that element.

You need to set it to something that has a value:

document.getElementById('mybox').style.display = "block";

What you're doing would work if you were replacing an inline style on the div, like this:

<div id="myBox" style="display: none;"></div>

document.getElementById('mybox').style.display = "";

How can I jump to class/method definition in Atom text editor?

Here are the shortcuts for both mac and windows:

For Mac: command + G

For Windows: CTRL+ALT+G

Can ordered list produce result that looks like 1.1, 1.2, 1.3 (instead of just 1, 2, 3, ...) with css?

this is proper code if you want to first child li resize of other css.

<style>
    li.title { 
        font-size: 20px; 

        counter-increment: ordem; 
        color:#0080B0;
    }
    .my_ol_class { 
        counter-reset: my_ol_class; 
        padding-left: 30px !important; 
    }
    .my_ol_class li { 
          display: block;
        position: relative;

    }
    .my_ol_class li:before { 
        counter-increment: my_ol_class; 
        content: counter(ordem) "." counter(my_ol_class) " "; 
        position: absolute;
        margin-right: 100%;
        right: 10px; /* space between number and text */
    }
    li.title ol li{
         font-size: 15px;
         color:#5E5E5E;
    }
</style>

in html file.

        <ol>
            <li class="title"> <p class="page-header list_title">Acceptance of Terms. </p>
                <ol class="my_ol_class">
                    <li> 
                        <p>
                            my text 1.
                        </p>
                    </li>
                    <li>
                        <p>
                            my text 2.
                        </p>
                    </li>
                </ol>
            </li>
        </ol>

What is the iPad user agent?

Safari on iPad user agent string in iPhone OS 3.2 SDK beta 3:

Mozilla/5.0 (iPad; U; CPU OS 3_2 like Mac OS X; en-us) AppleWebKit/531.21.10 (KHTML, like Gecko) Version/4.0.4 Mobile/7B334b Safari/531.21.10

More info: http://developer.apple.com/library/safari/#technotes/tn2010/tn2262/_index.html

Convert NSDate to NSString

NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:(NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay) fromDate:myNSDateInstance];
NSInteger year = [components year];
// NSInteger month = [components month];
NSString *yearStr = [NSString stringWithFormat:@"%ld", year];

What does this symbol mean in IntelliJ? (red circle on bottom-left corner of file name, with 'J' in it)

Close Android Studio and delete .idea and .gradle folder from project structure and start Studio again.

How to draw polygons on an HTML5 canvas?

//poly [x,y, x,y, x,y.....];
var poly=[ 5,5, 100,50, 50,100, 10,90 ];
var canvas=document.getElementById("canvas")
var ctx = canvas.getContext('2d');
ctx.fillStyle = '#f00';

ctx.beginPath();
ctx.moveTo(poly[0], poly[1]);
for( item=2 ; item < poly.length-1 ; item+=2 ){ctx.lineTo( poly[item] , poly[item+1] )}

ctx.closePath();
ctx.fill();

Certificate is trusted by PC but not by Android

You might be missing an intermediate certificate in your cert file. If you have already visited another website which has the same certificate seller, the intermediate certificate is remembered in your browser. This might not - or even better - will not be the case with every visitor to your website. To solve a missing intermediate certificate in the SSL connection, you will need to add the intermediate certificate to your own certificate file.

GoDaddy has some info on the intermediate certificates (but the best source is always your certificate provider): http://support.godaddy.com/help/article/868/what-is-an-intermediate-certificate

I once had this issue of an intermediate cert (with Commodo too) and had to combine my own cert file with the intermediate CA's to work. Once done no errors occurred anymore.

Installation instructions per webserver by Godaddy: http://support.godaddy.com/help/article/5346/installing-an-ssl-server-instructions?locale=en

And here is a list of the most common installation guides by Commodo themselves: https://support.comodo.com/index.php?/Default/Knowledgebase/Article/View/1145/0/how-do-i-make-my-own-bundle-file-from-crt-files

Depending on what webserver you are using, you'll need to specify all certificates (domain certificate, intermediate and root) or combine them into one (eg for Nginx) in the order:

  1. domain certificate
  2. intermediate certificate
  3. root certificate

An easy way of doing this in an SSH terminal is by typing:

cat domainfile intermediatefile rootfile > targetfile

Certificate test tool

If you encounter further problems or are unsure whether the certificate is correct, please try an online tool to verify your SSL certificate. For instance: networking4all.com/en/ssl+certificates/quickscan

SNI support for android 2.2 and lower

Please note android 2.2 (and probably older) do not support SNI, which allows multiple SSL certificates for different hostnames to work without issues on one single IP address. Thanks to @technyquist for providing that information. Please review this SO question about SNI for more information on this issue.

How do I best silence a warning about unused variables?

In C++11, this is the solution I'm using:

template<typename... Ts> inline void Unreferenced(Ts&&...) {}

int Foo(int bar) 
{
    Unreferenced(bar);
    return 0;
}

int Foo2(int bar1, int bar2) 
{
    Unreferenced(bar1, bar2);
    return 0;
}

Verified to be portable (at least on modern msvc, clang and gcc) and not producing extra code when optimizations are enabled. With no optimization, the extra function call is performed and references to the parameters are copied to the stack, but there are no macros involved.

If the extra code is an issue, you can use this declaration instead:

(decltype(Unreferenced(bar1, bar2)))0;

but at that point, a macro provides better readability:

#define UNREFERENCED(...) { (decltype(Unreferenced(__VA_ARGS__)))0; }

$watch an object

you must changes in $watch ....

_x000D_
_x000D_
function MyController($scope) {_x000D_
    $scope.form = {_x000D_
        name: 'my name',_x000D_
    }_x000D_
_x000D_
    $scope.$watch('form.name', function(newVal, oldVal){_x000D_
        console.log('changed');_x000D_
     _x000D_
    });_x000D_
}
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.22/angular.min.js"></script>_x000D_
<div ng-app>_x000D_
    <div ng-controller="MyController">_x000D_
        <label>Name:</label> <input type="text" ng-model="form.name"/>_x000D_
            _x000D_
        <pre>_x000D_
            {{ form }}_x000D_
        </pre>_x000D_
    </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

"Exception has been thrown by the target of an invocation" error (mscorlib)

This can happen when invoking a method that doesn't exist.

convert:not authorized `aaaa` @ error/constitute.c/ReadImage/453

I use many times the ImageMagic convert command to convert *.tif files to *.pdf files.

I don't know why but today I began to receive the following error:

convert: not authorized `a.pdf' @ error/constitute.c/WriteImage/1028.

After issuing the command:

convert a.tif a.pdf

After reading the above answers I edited the file /etc/ImageMagick-6/policy.xml

and changed the line:

policy domain="coder" rights="none" pattern="PDF" 

to

policy domain="coder" rights="read|write" pattern="PDF"

and now everything works fine.

I have "ImageMagick 6.8.9-9 Q16 x86_64 2018-09-28" on "Ubuntu 16.04.5 LTS".

How to delete all instances of a character in a string in python?

Strings are immutable in Python, which means once a string is created, you cannot alter the contents of the strings. If at all, you need to change it, a new instance of the string will be created with the alterations.

Having that in mind, we have so many ways to solve this

  1. Using str.replace,

    >>> "it is icy".replace("i", "")
    't s cy'
    
  2. Using str.translate,

    >>> "it is icy".translate(None, "i")
    't s cy'
    
  3. Using Regular Expression,

    >>> import re
    >>> re.sub(r'i', "", "it is icy")
    't s cy'
    
  4. Using comprehension as a filter,

    >>> "".join([char for char in "it is icy" if char != "i"])
    't s cy'
    
  5. Using filter function

    >>> "".join(filter(lambda char: char != "i", "it is icy"))
    't s cy'
    

Timing comparison

def findreplace(m_string, char):
    m_string = list(m_string)
    for k in m_string:
        if k == char:
            del(m_string[m_string.index(k)])
    return "".join(m_string)

def replace(m_string, char):
    return m_string.replace("i", "")

def translate(m_string, char):
    return m_string.translate(None, "i")

from timeit import timeit

print timeit("findreplace('it is icy','i')", "from __main__ import findreplace")
print timeit("replace('it is icy','i')", "from __main__ import replace")
print timeit("translate('it is icy','i')", "from __main__ import translate")

Result

1.64474582672
0.29278588295
0.311302900314

str.replace and str.translate methods are 8 and 5 times faster than the accepted answer.

Note: Comprehension method and filter methods are expected to be slower, for this case, since they have to create list and then they have to be traversed again to construct a string. And re is a bit overkill for a single character replacement. So, they all are excluded from the timing comparison.

How to filter keys of an object with lodash?

Just change filter to omitBy

_x000D_
_x000D_
const data = { aaa: 111, abb: 222, bbb: 333 };_x000D_
const result = _.omitBy(data, (value, key) => !key.startsWith("a"));_x000D_
console.log(result);
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.min.js"></script>
_x000D_
_x000D_
_x000D_

Find distance between two points on map using Google Map API V2

This is an old question with old answers. I want to highlight an updated way of calculating distance between two points. By now we should be familiar with the utility class, "SphericalUtil". You can retrieve the distance using that.

double distance = SphericalUtil.computeDistanceBetween(origin, dest);

TypeScript and React - children type?

You can use ReactChildren and ReactChild:

import React, { ReactChildren, ReactChild } from 'react';
 
interface AuxProps {
  children: ReactChild | ReactChildren;
}

const Aux = ({ children }: AuxProps) => (<div>{children}</div>);

export default Aux;

If you need to pass flat arrays of elements:

interface AuxProps {
  children: ReactChild | ReactChild[] | ReactChildren | ReactChildren[];
}

How to always show the vertical scrollbar in a browser?

jQuery shouldn't be required. You could try adding the CSS:

body    {overflow-y:scroll;}

This works across the latest browsers, even IE6.

How can I monitor the thread count of a process on linux?

If you want the number of threads per user in a linux system then you should use:

ps -eLf | grep <USER> | awk '{ num += $6 } END { print num }'

where as <USER> use the desired user name.

How do I fix the multiple-step OLE DB operation errors in SSIS?

This error is common when the source table contains a TEXT column and the target is anything other than a TEXT column. It can be a real time-eater if you have not encountered (or forgot!) this before.

Convert the text column to string and set the error condition on truncation to ignore. this will usually serve as a solution for this error.

how to install tensorflow on anaconda python 3.6

According to :https://anaconda.org/intel/tensorflow

To install this package with conda run:

conda install -c intel tensorflow

pip install To install this package with pip:

pip install -i https://pypi.anaconda.org/intel/simple tensorflow

Why does my Spring Boot App always shutdown immediately after starting?

Maybe it does not fit to your code but i found out if you have a code snippet like this:

@SpringBootApplication
public class SpringBootApacheKafkaApplication {

    public static void main(String[] args) {
        SpringApplication.run(SpringBootApacheKafkaApplication.class,args).close();
    }
}

then just remove the close() method. That's fixed my problem! Maybe I can help someone with that

How to get a jqGrid cell value when editing

Try this, it will give you particular column's value

onSelectRow: function(id) {
    var rowData = jQuery(this).getRowData(id); 
    var temp= rowData['name'];//replace name with you column
    alert(temp);
}

How do I calculate percentiles with python/numpy?

In case you need the answer to be a member of the input numpy array:

Just to add that the percentile function in numpy by default calculates the output as a linear weighted average of the two neighboring entries in the input vector. In some cases people may want the returned percentile to be an actual element of the vector, in this case, from v1.9.0 onwards you can use the "interpolation" option, with either "lower", "higher" or "nearest".

import numpy as np
x=np.random.uniform(10,size=(1000))-5.0

np.percentile(x,70) # 70th percentile

2.075966046220879

np.percentile(x,70,interpolation="nearest")

2.0729677997904314

The latter is an actual entry in the vector, while the former is a linear interpolation of two vector entries that border the percentile

What is the difference between `Enum.name()` and `Enum.toString()`?

Use toString when you need to display the name to the user.

Use name when you need the name for your program itself, e.g. to identify and differentiate between different enum values.

React Hooks useState() with Object

I leave you a utility function to inmutably update objects

/**
 * Inmutable update object
 * @param  {Object} oldObject     Object to update
 * @param  {Object} updatedValues Object with new values
 * @return {Object}               New Object with updated values
 */
export const updateObject = (oldObject, updatedValues) => {
  return {
    ...oldObject,
    ...updatedValues
  };
};

So you can use it like this

const MyComponent = props => {

  const [orderForm, setOrderForm] = useState({
    specialities: {
      elementType: "select",
      elementConfig: {
        options: [],
        label: "Specialities"
      },
      touched: false
    }
  });


// I want to update the options list, to fill a select element

  // ---------- Update with fetched elements ---------- //

  const updateSpecialitiesData = data => {
    // Inmutably update elementConfig object. i.e label field is not modified
    const updatedOptions = updateObject(
      orderForm[formElementKey]["elementConfig"],
      {
        options: data
      }
    );
    // Inmutably update the relevant element.
    const updatedFormElement = updateObject(orderForm[formElementKey], {
      touched: true,
      elementConfig: updatedOptions
    });
    // Inmutably update the relevant element in the state.
    const orderFormUpdated = updateObject(orderForm, {
      [formElementKey]: updatedFormElement
    });
    setOrderForm(orderFormUpdated);
  };

  useEffect(() => {
      // some code to fetch data
      updateSpecialitiesData.current("specialities",fetchedData);
  }, [updateSpecialitiesData]);

// More component code
}

If not you have more utilities here : https://es.reactjs.org/docs/update.html

Android Studio error: "Environment variable does not point to a valid JVM installation"

Just set the Environment variable to JAVA_HOME of

C:\Program Files\Java\jdk1.7.0_51)

with out bin for 64 bit version and same for 32 bit version with Program Files(x86).

NO \BIN after the path it will work properly.

How to find out "The most popular repositories" on Github?

Ranking by stars or forks is not working. Each promoted or created by a famous company repository is popular at the beginning. Also it is possible to have a number of them which are in trend right now (publications, marketing, events). It doesn't mean that those repositories are useful/popular.

The gitmostwanted.com project (repo at github) analyses GH Archive data in order to highlight the most interesting repositories and exclude others. Just compare the results with mentioned resources.

how to place last div into right top corner of parent div? (css)

_x000D_
_x000D_
.block1 {_x000D_
    color: red;_x000D_
    width: 100px;_x000D_
    border: 1px solid green;_x000D_
    position: relative;_x000D_
}_x000D_
_x000D_
.block2 {_x000D_
    color: blue;_x000D_
    width: 70px;_x000D_
    border: 2px solid black;_x000D_
    position: absolute;_x000D_
    top: 0px;_x000D_
    right: 0px;_x000D_
}
_x000D_
<div class='block1'>_x000D_
  <p>text</p>_x000D_
  <p>text2</p>_x000D_
  <div class='block2'>block2</div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Should do it. Assuming you don't need it to flow.

Best way to make WPF ListView/GridView sort on column-header clicking?

I wrote a set of attached properties to automatically sort a GridView, you can check it out here. It doesn't handle the up/down arrow, but it could easily be added.

<ListView ItemsSource="{Binding Persons}"
          IsSynchronizedWithCurrentItem="True"
          util:GridViewSort.AutoSort="True">
    <ListView.View>
        <GridView>
            <GridView.Columns>
                <GridViewColumn Header="Name"
                                DisplayMemberBinding="{Binding Name}"
                                util:GridViewSort.PropertyName="Name"/>
                <GridViewColumn Header="First name"
                                DisplayMemberBinding="{Binding FirstName}"
                                util:GridViewSort.PropertyName="FirstName"/>
                <GridViewColumn Header="Date of birth"
                                DisplayMemberBinding="{Binding DateOfBirth}"
                                util:GridViewSort.PropertyName="DateOfBirth"/>
            </GridView.Columns>
        </GridView>
    </ListView.View>
</ListView>

.jar error - could not find or load main class

I found this question when I was looking for the answer to the above question. But in my case the issue was the use of an 'en dash' rather than a 'dash'. Check which dash you are using, it might be the wrong one. I hope this answer speeds up someone else's search, a comment like this could have saved me a bit of time.

When to use RSpec let()?

I use let to test my HTTP 404 responses in my API specs using contexts.

To create the resource, I use let!. But to store the resource identifier, I use let. Take a look how it looks like:

let!(:country)   { create(:country) }
let(:country_id) { country.id }
before           { get "api/countries/#{country_id}" }

it 'responds with HTTP 200' { should respond_with(200) }

context 'when the country does not exist' do
  let(:country_id) { -1 }
  it 'responds with HTTP 404' { should respond_with(404) }
end

That keeps the specs clean and readable.

Unix command to check the filesize

ls -lh file.txt | awk '{ print $5 }'

Spring JPA @Query with LIKE

List<User> findByUsernameContainingIgnoreCase(String username);

in order to ignore case issues

Google Maps API 3 - Custom marker color for default (dot) marker

Here is a nice solution using the Gooogle Maps API itself. No external service, no extra library. And it enables custom shapes and multiple colors and styles. The solution uses vectorial markers, which googlemaps api calls Symbols.

Besides the few and limited predefined symbols, you can craft any shape of any color by specifying an SVG path string (Spec).

To use it, instead of setting the 'icon' marker option to the image url, you set it to a dictionary containing the symbol options. As example, I managed to craft one symbol that is quite similar to the standard marker:

function pinSymbol(color) {
    return {
        path: 'M 0,0 C -2,-20 -10,-22 -10,-30 A 10,10 0 1,1 10,-30 C 10,-22 2,-20 0,0 z M -2,-30 a 2,2 0 1,1 4,0 2,2 0 1,1 -4,0',
        fillColor: color,
        fillOpacity: 1,
        strokeColor: '#000',
        strokeWeight: 2,
        scale: 1,
   };
}

var marker = new google.maps.Marker({
   map: map,
   position: new google.maps.LatLng(latitude, longitude),
   icon: pinSymbol("#FFF"),
});

Vector Marker

I you are careful to keep the shape key point at 0,0 you avoid having to define marker icon centering parameters. Another path example, the same marker without the dot:

    path: 'M 0,0 C -2,-20 -10,-22 -10,-30 A 10,10 0 1,1 10,-30 C 10,-22 2,-20 0,0 z',

Dotless Vector Marker

And here you have a very simple and ugly coloured flag:

    path: 'M 0,0 -1,-2 V -43 H 1 V -2 z M 1,-40 H 30 V -20 H 1 z',

Vector Flag

You can also create the paths using a visual tool like Inkscape (GNU-GPL, multiplatform). Some useful hints:

  • Google API just accepts a single path, so you have to turn any other object (square, cercle...) into a path and join them as a single one. Both commands at the Path menu.
  • To move the path to the (0,0), go to the Path Edit mode (F2) select all the control nodes and drag them. Moving the object with F1, won't change the path node coords.
  • To ensure the reference point is at (0,0), you can select it alone and edit the coords by hand on the top toolbar.
  • After saving the SVG file, which is an XML, open it with an editor, look for the svg:path element and copy the content of the 'd' attribute.

How do I add button on each row in datatable?

take a look here... this was very helpfull to me https://datatables.net/examples/ajax/null_data_source.html

$(document).ready(function() {
    var table = $('#example').DataTable( {
        "ajax": "data/arrays.txt",
        "columnDefs": [ {
        "targets": -1,
        "data": null,
        "defaultContent": "<button>Click!</button>"
    } ]
} );

$('#example tbody').on( 'click', 'button', function () {
    var data = table.row( $(this).parents('tr') ).data();
    alert( data[0] +"'s salary is: "+ data[ 5 ] );
    } );
} );

Is it safe to clean docker/overlay2/

I used "docker system prune -a" it cleaned all files under volumes and overlay2

    [root@jasontest volumes]# docker system prune -a
    WARNING! This will remove:
            - all stopped containers
            - all networks not used by at least one container
            - all images without at least one container associated to them
            - all build cache
    Are you sure you want to continue? [y/N] y
    Deleted Images:
    untagged: ubuntu:12.04
    untagged: ubuntu@sha256:18305429afa14ea462f810146ba44d4363ae76e4c8dfc38288cf73aa07485005
    deleted: sha256:5b117edd0b767986092e9f721ba2364951b0a271f53f1f41aff9dd1861c2d4fe
    deleted: sha256:8c7f3d7534c80107e3a4155989c3be30b431624c61973d142822b12b0001ece8
    deleted: sha256:969d5a4e73ab4e4b89222136eeef2b09e711653b38266ef99d4e7a1f6ea984f4
    deleted: sha256:871522beabc173098da87018264cf3e63481628c5080bd728b90f268793d9840
    deleted: sha256:f13e8e542cae571644e2f4af25668fadfe094c0854176a725ebf4fdec7dae981
    deleted: sha256:58bcc73dcf4050a4955916a0dcb7e5f9c331bf547d31e22052f1b5fa16cf63f8
    untagged: osixia/openldap:1.2.1
    untagged: osixia/openldap@sha256:6ceb347feb37d421fcabd80f73e3dc6578022d59220cab717172ea69c38582ec
    deleted: sha256:a562f6fd60c7ef2adbea30d6271af8058c859804b2f36c270055344739c06d64
    deleted: sha256:90efa8a88d923fb1723bea8f1082d4741b588f7fbcf3359f38e8583efa53827d
    deleted: sha256:8d77930b93c88d2cdfdab0880f3f0b6b8be191c23b04c61fa1a6960cbeef3fe6
    deleted: sha256:dd9f76264bf3efd36f11c6231a0e1801c80d6b4ca698cd6fa2ff66dbd44c3683
    deleted: sha256:00efc4fb5e8a8e3ce0cb0047e4c697646c88b68388221a6bd7aa697529267554
    deleted: sha256:e64e6259fd63679a3b9ac25728f250c3afe49dbe457a1a80550b7f1ccf68458a
    deleted: sha256:da7d34d626d2758a01afe816a9434e85dffbafbd96eb04b62ec69029dae9665d
    deleted: sha256:b132dace06fa7e22346de5ca1ae0c2bf9acfb49fe9dbec4290a127b80380fe5a
    deleted: sha256:d626a8ad97a1f9c1f2c4db3814751ada64f60aed927764a3f994fcd88363b659
    untagged: centos:centos7
    untagged: centos@sha256:2671f7a3eea36ce43609e9fe7435ade83094291055f1c96d9d1d1d7c0b986a5d
    deleted: sha256:ff426288ea903fcf8d91aca97460c613348f7a27195606b45f19ae91776ca23d
    deleted: sha256:e15afa4858b655f8a5da4c4a41e05b908229f6fab8543434db79207478511ff7

    Total reclaimed space: 533.3MB
    [root@jasontest volumes]# ls -alth
    total 32K
    -rw-------  1 root root  32K May 23 21:14 metadata.db
    drwx------  2 root root 4.0K May 23 21:14 .
    drwx--x--x 14 root root 4.0K May 21 20:26 ..

Sum of values in an array using jQuery

You can do it in this way.

var somearray = ["20","40","80","400"];

somearray = somearray.map(Number);

var total = somearray.reduce(function(a,b){  return a+b },0)

console.log(total);

Can I use DIV class and ID together in CSS?

Yes you can.

You just need to understand what they are for, the class is more general and can be used several times, the id (is like your id's) you can use it only once.

This excellent tutorial helped me with that:

The Difference Between ID and Class

Though it's not an exact answer to your question I'm sure it will help you a lot!

Good luck!

EDIT: Reading your question, I just want to clarify that:

<div class="x" id="y">
    --
</div>

And that if you want to "use them" in CSS for styling purposes you should do as David Says: #x.y { }

How can I sort a dictionary by key?

Standard Python dictionaries are unordered. Even if you sorted the (key,value) pairs, you wouldn't be able to store them in a dict in a way that would preserve the ordering.

The easiest way is to use OrderedDict, which remembers the order in which the elements have been inserted:

In [1]: import collections

In [2]: d = {2:3, 1:89, 4:5, 3:0}

In [3]: od = collections.OrderedDict(sorted(d.items()))

In [4]: od
Out[4]: OrderedDict([(1, 89), (2, 3), (3, 0), (4, 5)])

Never mind the way od is printed out; it'll work as expected:

In [11]: od[1]
Out[11]: 89

In [12]: od[3]
Out[12]: 0

In [13]: for k, v in od.iteritems(): print k, v
   ....: 
1 89
2 3
3 0
4 5

Python 3

For Python 3 users, one needs to use the .items() instead of .iteritems():

In [13]: for k, v in od.items(): print(k, v)
   ....: 
1 89
2 3
3 0
4 5

Is it valid to define functions in JSON results?

Leave the quotes off...

var a = {"b":function(){alert('hello world');} };

a.b();

How do you use the Immediate Window in Visual Studio?

One nice feature of the Immediate Window in Visual Studio is its ability to evaluate the return value of a method particularly if it is called by your client code but it is not part of a variable assignment. In Debug mode, as mentioned, you can interact with variables and execute expressions in memory which plays an important role in being able to do this.

For example, if you had a static method that returns the sum of two numbers such as:

private static int GetSum(int a, int b)
{
    return a + b;
}

Then in the Immediate Window you can type the following:

? GetSum(2, 4)
6

As you can seen, this works really well for static methods. However, if the method is non-static then you need to interact with a reference to the object the method belongs to.

For example, let’s say this is what your class looks like:

private class Foo
{
    public string GetMessage()
    {
        return "hello";
    }
}

If the object already exists in memory and it’s in scope, then you can call it in the Immediate Window as long as it has been instantiated before your current breakpoint (or, at least, before wherever the code is paused in debug mode):

? foo.GetMessage(); // object ‘foo’ already exists
"hello"

In addition, if you want to interact and test the method directly without relying on an existing instance in memory, then you can instantiate your own instance in the Immediate Window:

? Foo foo = new Foo(); // new instance of ‘Foo’
{temp.Program.Foo}
? foo.GetMessage()
"hello"

You can take it a step further and temporarily assign the method's results to variables if you want to do further evaluations, calculations, etc.:

? string msg = foo.GetMessage();
"hello"
? msg + " there!"
"hello there!"

Furthermore, if you don’t even want to declare a variable name for a new object and just want to run one of its methods/functions then do this:

? new Foo().GetMessage()
"hello" 

A very common way to see the value of a method is to select the method name of a class and do a ‘Add Watch’ so that you can see its current value in the Watch window. However, once again, the object needs to be instantiated and in scope for a valid value to be displayed. This is much less powerful and more restrictive than using the Immediate Window.

Along with inspecting methods, you can do simple math equations:

? 5 * 6
30

or compare values:

? 5==6
false
? 6==6
true

The question mark ('?') is unnecessary if you are in directly in the Immediate Window but it is included here for clarity (to distinguish between the typed in expressions versus the results.) However, if you are in the Command Window and need to do some quick stuff in the Immediate Window then precede your statements with '?' and off you go.

Intellisense works in the Immediate Window, but it sometimes can be a bit inconsistent. In my experience, it seems to be only available in Debug mode, but not in design, non-debug mode.

Unfortunately, another drawback of the Immediate Window is that it does not support loops.

How can I compare two time strings in the format HH:MM:SS?

Set the extracted part of the time to variables.

// If you don't have the second part then set it to 00.

 //Create date object and set the time to that
 var startTimeObject = new Date();
 startTimeObject.setHours(startHour, startMinute, startSecond);

 //Create date object and set the time to that
 var endTimeObject = new Date(startTimeObject);
 endTimeObject.setHours(endHour, endMinute, endSecond);

 //Now we are ready to compare both the dates
 if(startTimeObject > endTimeObject) {
     alert('End time should be after start time.');
 }
 else {
     alert('Entries are perfect.');
 }

How to create an email form that can send email using html

you can use Simple Contact Form in HTML with PHP mailer. It's easy to implement in you website. You can try the demo from following link: Simple Contact/Feedback Form in HTML-PHP mailer

Otherwise you can watch the demo video in following link: Youtube: Simple Contact/Feedback Form in HTML-PHP mailer

When you are running in localhost, you may get following error:

Warning: mail(): Failed to connect to mailserver at "smtp.gmail.com" port 25, verify your "SMTP" and "smtp_port" setting in php.ini or use ini_set() in S:\wamp\www\sample\mailTo.php on line 10

You can check in this link for more detailed information: Simple Contact/Feedback Form in HTML with php (HTML-PHP mailer) And this is the screenshot of HTML form: Simple Form

And this is the main PHP coding:

<?php
if($_POST["submit"]) {
    $recipient="[email protected]"; //Enter your mail address
    $subject="Contact from Website"; //Subject 
    $sender=$_POST["name"];
    $senderEmail=$_POST["email"];
    $message=$_POST["comments"];
    $mailBody="Name: $sender\nEmail Address: $senderEmail\n\nMessage: $message";
    mail($recipient, $subject, $mailBody);
    sleep(1);
    header("Location:http://blog.antonyraphel.in/sample/"); // Set here redirect page or destination page
}
?>

How to use OpenCV SimpleBlobDetector

Note: all the examples here are using the OpenCV 2.X API.

In OpenCV 3.X, you need to use:

Ptr<SimpleBlobDetector> d = SimpleBlobDetector::create(params);

See also: the transition guide: http://docs.opencv.org/master/db/dfa/tutorial_transition_guide.html#tutorial_transition_hints_headers

PHP Composer update "cannot allocate memory" error (using Laravel 4)

I get into this situation most of the times so normally i used to follow the step of setting the swap memory.

But now i found a simple alternate trick which worked for me.

Run composer update --no-dev Other than composer update

Change app language programmatically in Android

/*change language at Run-time*/
//use method like that:
//setLocale("en");
 public void setLocale(String lang) { 
  myLocale = new Locale(lang);         
  Resources res = getResources();         
  DisplayMetrics dm = res.getDisplayMetrics();         
  Configuration conf = res.getConfiguration();         
  conf.locale = myLocale;         
  res.updateConfiguration(conf, dm);         
  Intent refresh = new Intent(this, AndroidLocalize.class);         
  startActivity(refresh); 
 }

Get the decimal part from a double

var decPlaces = (int)(((decimal)number % 1) * 100);

This presumes your number only has two decimal places.

How to make matrices in Python?

you can do it short like this:

matrix = [["A, B, C, D, E"]*5]
print(matrix)


[['A, B, C, D, E', 'A, B, C, D, E', 'A, B, C, D, E', 'A, B, C, D, E', 'A, B, C, D, E']]

Expanding a parent <div> to the height of its children

_x000D_
_x000D_
#childRightCol_x000D_
{_x000D_
float:right;_x000D_
}_x000D_
#childLeftCol_x000D_
{_x000D_
float:left;_x000D_
}_x000D_
#parent_x000D_
{_x000D_
    display:inline;_x000D_
}
_x000D_
_x000D_
_x000D_

Tool to convert java to c# code

For your reference:

Note: I had no experience on them.

How to apply font anti-alias effects in CSS?

Works the best. If you want to use it sitewide, without having to add this syntax to every class or ID, add the following CSS to your css body:

body { 
    -webkit-font-smoothing: antialiased;
    text-shadow: 1px 1px 1px rgba(0,0,0,0.004);
    background: url('./images/background.png');
    text-align: left;
    margin: auto;

}

Embedding JavaScript engine into .NET

V8.NET is a new kid on the block (as of April 2013) that more closely wraps the native V8 engine functionality. It allows for more control over the implementation.

Bootstrap get div to align in the center

In bootstrap you can use .text-centerto align center. also add .row and .col-md-* to your code.

align= is deprecated,

Added .col-xs-* for demo

_x000D_
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css" rel="stylesheet" />
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet" />
<div class="footer">
  <div class="container">
    <div class="row">
      <div class="col-xs-4">
        <p>Hello there</p>
      </div>
      <div class="col-xs-4 text-center">
        <a href="#" class="btn btn-warning" onclick="changeLook()">Re</a>
        <a href="#" class="btn btn-warning" onclick="changeBack()">Rs</a>
      </div>
      <div class="col-xs-4 text-right">
        <a href="#"><i class="fa fa-facebook-square fa-2x"></i></a>
        <a href="#"><i class="fa fa-twitter fa-2x"></i></a>
        <a href="#"><i class="fa fa-google-plus fa-2x"></i></a>
      </div>
    </div>
  </div>
</div>
_x000D_
_x000D_
_x000D_

UPDATE(OCT 2017)

For those who are reading this and want to use the new version of bootstrap (beta version), you can do the above in a simpler way, using Boostrap Flexbox utilities classes

_x000D_
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.5.0/css/font-awesome.min.css" rel="stylesheet" />
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" rel="stylesheet" />
<div class="container footer">
  <div class="d-flex justify-content-between">
    <div class="p-1">
      <p>Hello there</p>
    </div>
    <div class="p-1">
      <a href="#" class="btn btn-warning" onclick="changeLook()">Re</a>
      <a href="#" class="btn btn-warning" onclick="changeBack()">Rs</a>
    </div>
    <div class="p-1">
      <a href="#"><i class="fa fa-facebook-square fa-2x"></i></a>
      <a href="#"><i class="fa fa-twitter fa-2x"></i></a>
      <a href="#"><i class="fa fa-google-plus fa-2x"></i></a>
    </div>
  </div>
</div>
_x000D_
_x000D_
_x000D_

How to change link color (Bootstrap)

For a direct change, you can use Bootstrap classes in the <a> tag (it won't work in the <div>):

<h4 class="text-center"><a class="text-warning" href="#">Your text</a></h4>

Where can I find documentation on formatting a date in JavaScript?

I was unable to find any definitive documentation on valid date formats so I wrote my own test to see what is supported in various browsers.

http://blarg.co.uk/blog/javascript-date-formats

My results concluded the following formats are valid in all browsers that I tested (examples use the date "9th August 2013"):

[Full Year]/[Month]/[Date number] - Month can be either the number with or without a leading zero or the month name in short or long format, and date number can be with or without a leading zero.

  • 2013/08/09
  • 2013/08/9
  • 2013/8/09
  • 2013/8/9
  • 2013/August/09
  • 2013/August/9
  • 2013/Aug/09
  • 2013/Aug/9

[Month]/[Full Year]/[Date Number] - Month can be either the number with or without a leading zero or the month name in short or long format, and date number can be with or without a leading zero.

  • 08/2013/09
  • 08/2013/9
  • 8/2013/09
  • 8/2013/9
  • August/2013/09
  • August/2013/9
  • Aug/2013/09
  • Aug/2013/9

Any combination of [Full Year], [Month Name] and [Date Number] separated by spaces - Month name can be in either short or long format, and date number can be with or without a leading zero.

  • 2013 August 09
  • August 2013 09
  • 09 August 2013
  • 2013 Aug 09
  • Aug 9 2013
  • 2013 9 Aug
  • etc...

Also valid in "modern browsers" (or in other words all browsers except IE9 and below)

[Full Year]-[Month Number]-[Date Number] - Month and Date Number must include leading zeros (this is the format that the MySQL Date type uses)

  • 2013-08-09

Using month names:
Interestingly, when using month names I discovered that only the first 3 characters of the month name are ever used so all the of the following are perfectly valid:

new Date('9 August 2013');
new Date('9 Aug 2013');
new Date('9 Augu 2013');
new Date('9 Augustagfsdgsd 2013');

Scatter plot and Color mapping in Python

Here is an example

import numpy as np
import matplotlib.pyplot as plt

x = np.random.rand(100)
y = np.random.rand(100)
t = np.arange(100)

plt.scatter(x, y, c=t)
plt.show()

Here you are setting the color based on the index, t, which is just an array of [1, 2, ..., 100]. enter image description here

Perhaps an easier-to-understand example is the slightly simpler

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(100)
y = x
t = x
plt.scatter(x, y, c=t)
plt.show()

enter image description here

Note that the array you pass as c doesn't need to have any particular order or type, i.e. it doesn't need to be sorted or integers as in these examples. The plotting routine will scale the colormap such that the minimum/maximum values in c correspond to the bottom/top of the colormap.

Colormaps

You can change the colormap by adding

import matplotlib.cm as cm
plt.scatter(x, y, c=t, cmap=cm.cmap_name)

Importing matplotlib.cm is optional as you can call colormaps as cmap="cmap_name" just as well. There is a reference page of colormaps showing what each looks like. Also know that you can reverse a colormap by simply calling it as cmap_name_r. So either

plt.scatter(x, y, c=t, cmap=cm.cmap_name_r)
# or
plt.scatter(x, y, c=t, cmap="cmap_name_r")

will work. Examples are "jet_r" or cm.plasma_r. Here's an example with the new 1.5 colormap viridis:

import numpy as np
import matplotlib.pyplot as plt

x = np.arange(100)
y = x
t = x
fig, (ax1, ax2) = plt.subplots(1, 2)
ax1.scatter(x, y, c=t, cmap='viridis')
ax2.scatter(x, y, c=t, cmap='viridis_r')
plt.show()

enter image description here

Colorbars

You can add a colorbar by using

plt.scatter(x, y, c=t, cmap='viridis')
plt.colorbar()
plt.show()

enter image description here

Note that if you are using figures and subplots explicitly (e.g. fig, ax = plt.subplots() or ax = fig.add_subplot(111)), adding a colorbar can be a bit more involved. Good examples can be found here for a single subplot colorbar and here for 2 subplots 1 colorbar.

Concatenating null strings in Java

Why must it work?

The JLS 5, Section 15.18.1.1 JLS 8 § 15.18.1 "String Concatenation Operator +", leading to JLS 8, § 5.1.11 "String Conversion", requires this operation to succeed without failure:

...Now only reference values need to be considered. If the reference is null, it is converted to the string "null" (four ASCII characters n, u, l, l). Otherwise, the conversion is performed as if by an invocation of the toString method of the referenced object with no arguments; but if the result of invoking the toString method is null, then the string "null" is used instead.

How does it work?

Let's look at the bytecode! The compiler takes your code:

String s = null;
s = s + "hello";
System.out.println(s); // prints "nullhello"

and compiles it into bytecode as if you had instead written this:

String s = null;
s = new StringBuilder(String.valueOf(s)).append("hello").toString();
System.out.println(s); // prints "nullhello"

(You can do so yourself by using javap -c)

The append methods of StringBuilder all handle null just fine. In this case because null is the first argument, String.valueOf() is invoked instead since StringBuilder does not have a constructor that takes any arbitrary reference type.

If you were to have done s = "hello" + s instead, the equivalent code would be:

s = new StringBuilder("hello").append(s).toString();

where in this case the append method takes the null and then delegates it to String.valueOf().

Note: String concatenation is actually one of the rare places where the compiler gets to decide which optimization(s) to perform. As such, the "exact equivalent" code may differ from compiler to compiler. This optimization is allowed by JLS, Section 15.18.1.2:

To increase the performance of repeated string concatenation, a Java compiler may use the StringBuffer class or a similar technique to reduce the number of intermediate String objects that are created by evaluation of an expression.

The compiler I used to determine the "equivalent code" above was Eclipse's compiler, ecj.

How to find out if an item is present in a std::vector?

You can try this code:

#include <algorithm>
#include <vector>

// You can use class, struct or primitive data type for Item
struct Item {
    //Some fields
};
typedef std::vector<Item> ItemVector;
typedef ItemVector::iterator ItemIterator;
//...
ItemVector vtItem;
//... (init data for vtItem)
Item itemToFind;
//...

ItemIterator itemItr;
itemItr = std::find(vtItem.begin(), vtItem.end(), itemToFind);
if (itemItr != vtItem.end()) {
    // Item found
    // doThis()
}
else {
    // Item not found
    // doThat()
}

Adding a column to an existing table in a Rails migration

You can also do this .. rails g migration add_column_to_users email:string

then rake db:migrate also add :email attribute in your user controller ;

for more detail check out http://guides.rubyonrails.org/active_record_migrations.html

How to check compiler log in sql developer?

To see your log in SQL Developer then press:

CTRL+SHIFT + L (or CTRL + CMD + L on macOS)

or

View -> Log

or by using mysql query

show errors;

Prevent screen rotation on Android

Add the following to your AndroidManifest.xml

[ app > src > main > AndroidManifest.xml ]

<activity android:name=".MainActivity"
          android:configChanges="orientation"
          android:screenOrientation="portrait"/>

Example:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="xxx.zzzzzz.yyyyy">

   <uses-permission android:name="A-PERMISSION" />

   <application>
      <activity android:name=".MainActivity"
                android:screenOrientation="portrait"
                android:configChanges="orientation">
      </activity>
   </application>

</manifest>

The input is not a valid Base-64 string as it contains a non-base 64 character

Probably the string would be like this data:image/jpeg;base64,/9j/4QN8RXh... First split for / and get the second token.

var StrAfterSlash = Face.Split('/')[1];

Then Split for ; and get the first token which will be the format. In my case it's jpeg.

var ImageFormat =StrAfterSlash.Split(';')[0];

Then remove the line data:image/jpeg;base64, for the collected format

CleanFaceData=Face.Replace($"data:image/{ImageFormat };base64,",string.Empty);

Opening database file from within SQLite command-line shell

I think the simplest way to just open a single database and start querying is:

sqlite> .open "test.db"
sqlite> SELECT * FROM table_name ... ;

Notice: This works only for versions 3.8.2+

How to set Oracle's Java as the default Java in Ubuntu?

to set Oracle's Java SE Development Kit as the system default Java just download the latest Java SE Development Kit from here then create a directory somewhere you like in your file system for example /usr/java now extract the files you just downloaded in that directory:

$ sudo tar xvzf jdk-8u5-linux-i586.tar.gz -C /usr/java

now to set your JAVA_HOME environment variable:

$ JAVA_HOME=/usr/java/jdk1.8.0_05/
$ sudo update-alternatives --install /usr/bin/java java ${JAVA_HOME%*/}/bin/java 20000
$ sudo update-alternatives --install /usr/bin/javac javac ${JAVA_HOME%*/}/bin/javac 20000

make sure the Oracle's java is set as default java by:

$ update-alternatives --config java

you get something like this:

There are 2 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                           Priority   Status
------------------------------------------------------------
* 0            /opt/java/jdk1.8.0_05/bin/java                  20000     auto mode
  1            /opt/java/jdk1.8.0_05/bin/java                  20000     manual mode
  2            /usr/lib/jvm/java-6-openjdk-i386/jre/bin/java   1061      manual mode

Press enter to keep the current choice[*], or type selection number:

pay attention to the asterisk before the numbers on the left and if the correct one is not set choose the correct one by typing the number of it and pressing enter. now test your java:

$ java -version

if you get something like the following, you are good to go:

java version "1.8.0_05"
Java(TM) SE Runtime Environment (build 1.8.0_05-b13)
Java HotSpot(TM) Server VM (build 25.5-b02, mixed mode)

also note that you might need root permission or be in sudoers group to be able to do this. I've tested this solution on both ubuntu 12.04 and Debian wheezy and it works in both of them.

serialize/deserialize java 8 java.time with Jackson JSON mapper

If you can't use jackson-modules-java8 for whatever reasons you can (de-)serialize the instant field as long using @JsonIgnore and @JsonGetter & @JsonSetter:

public class MyBean {

    private Instant time = Instant.now();

    @JsonIgnore
    public Instant getTime() {
        return this.time;
    }

    public void setTime(Instant time) {
        this.time = time;
    }

    @JsonGetter
    private long getEpochTime() {
        return this.time.toEpochMilli();
    }

    @JsonSetter
    private void setEpochTime(long time) {
        this.time = Instant.ofEpochMilli(time);
    }
}

Example:

@Test
public void testJsonTime() throws Exception {
    String json = new ObjectMapper().writeValueAsString(new MyBean());
    System.out.println(json);
    MyBean myBean = new ObjectMapper().readValue(json, MyBean.class);
    System.out.println(myBean.getTime());
}

yields

{"epochTime":1506432517242}
2017-09-26T13:28:37.242Z

Java String remove all non numeric characters

With guava:

String input = "abx123.5";
String result = CharMatcher.inRange('0', '9').or(CharMatcher.is('.')).retainFrom(input);

see http://code.google.com/p/guava-libraries/wiki/StringsExplained

Simple UDP example to send and receive data from same socket

here is my soln to define the remote and local port and then write out to a file the received data, put this all in a class of your choice with the correct imports

    static UdpClient sendClient = new UdpClient();
    static int localPort = 49999;
    static int remotePort = 49000;
    static IPEndPoint localEP = new IPEndPoint(IPAddress.Any, localPort);
    static IPEndPoint remoteEP = new IPEndPoint(IPAddress.Parse("127.0.0.1"), remotePort);
    static string logPath = System.AppDomain.CurrentDomain.BaseDirectory + "/recvd.txt";
    static System.IO.StreamWriter fw = new System.IO.StreamWriter(logPath, true);


    private static void initStuff()
    {
      
        fw.AutoFlush = true;
        sendClient.ExclusiveAddressUse = false;
        sendClient.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
        sendClient.Client.Bind(localEP);
        sendClient.BeginReceive(DataReceived, sendClient);
    }

    private static void DataReceived(IAsyncResult ar)
    {
        UdpClient c = (UdpClient)ar.AsyncState;
        IPEndPoint receivedIpEndPoint = new IPEndPoint(IPAddress.Any, 0);
        Byte[] receivedBytes = c.EndReceive(ar, ref receivedIpEndPoint);
        fw.WriteLine(DateTime.Now.ToString("HH:mm:ss.ff tt") +  " (" + receivedBytes.Length + " bytes)");

        c.BeginReceive(DataReceived, ar.AsyncState);
    }


    static void Main(string[] args)
    {
        initStuff();
        byte[] emptyByte = {};
        sendClient.Send(emptyByte, emptyByte.Length, remoteEP);
    }

How to make full screen background in a web page

A quick search for keywords background generator shows this CSS3 produced background pattern that's dynamically created.

By keeping the image small and repeatable, you won't have problems with it loading on mobile devices and the small image file-size takes care of memory concerns.

Here's the markup for the head section:

<style type="text/css">

    body {
      background-image:url('path/to/your/image/background.png');
      width: 100%;
      height: 100%;
    }

</style>

If your going to use an image of something that should preserve aspect ratio, such as people or objects, then you don't want 100% for width and height since that will stretch the image out of proportion. Instead check out this quick tutorial that shows different methods for applying background images using CSS.

SQL query to find record with ID not in another table

There are basically 3 approaches to that: not exists, not in and left join / is null.

LEFT JOIN with IS NULL

SELECT  l.*
FROM    t_left l
LEFT JOIN
        t_right r
ON      r.value = l.value
WHERE   r.value IS NULL

NOT IN

SELECT  l.*
FROM    t_left l
WHERE   l.value NOT IN
        (
        SELECT  value
        FROM    t_right r
        )

NOT EXISTS

SELECT  l.*
FROM    t_left l
WHERE   NOT EXISTS
        (
        SELECT  NULL
        FROM    t_right r
        WHERE   r.value = l.value
        )

Which one is better? The answer to this question might be better to be broken down to major specific RDBMS vendors. Generally speaking, one should avoid using select ... where ... in (select...) when the magnitude of number of records in the sub-query is unknown. Some vendors might limit the size. Oracle, for example, has a limit of 1,000. Best thing to do is to try all three and show the execution plan.

Specifically form PostgreSQL, execution plan of NOT EXISTS and LEFT JOIN / IS NULL are the same. I personally prefer the NOT EXISTS option because it shows better the intent. After all the semantic is that you want to find records in A that its pk do not exist in B.

Old but still gold, specific to PostgreSQL though: https://explainextended.com/2009/09/16/not-in-vs-not-exists-vs-left-join-is-null-postgresql/

Showing loading animation in center of page while making a call to Action method in ASP .NET MVC

This is how did it works like a charm.

CSS

#loader {
position:fixed;
left:1px;
top:1px;
width: 100%;
height: 100%;
z-index: 9999;

background: url('../images/ajax-loader100X100.gif') 50% 50% no-repeat rgb(249,249,249);
}  

in _layout file inside body tag but outside the container div. Every time page loads it shows loading. Once page is loaded JS fadeout(second)


<div id="loader">
</div>

JS at the bottom of _layout file


<script type="text/javascript">
// With the element initially shown, we can hide it slowly:
 $("#loader").fadeOut(1000);
</script>  

Retrieving Property name from lambda expression

Starting with .NET 4.0 you can use ExpressionVisitor to find properties:

class ExprVisitor : ExpressionVisitor {
    public bool IsFound { get; private set; }
    public string MemberName { get; private set; }
    public Type MemberType { get; private set; }
    protected override Expression VisitMember(MemberExpression node) {
        if (!IsFound && node.Member.MemberType == MemberTypes.Property) {
            IsFound = true;
            MemberName = node.Member.Name;
            MemberType = node.Type;
        }
        return base.VisitMember(node);
    }
}

Here is how you use this visitor:

var visitor = new ExprVisitor();
visitor.Visit(expr);
if (visitor.IsFound) {
    Console.WriteLine("First property in the expression tree: Name={0}, Type={1}", visitor.MemberName, visitor.MemberType.FullName);
} else {
    Console.WriteLine("No properties found.");
}

How to Generate Unique Public and Private Key via RSA

What I ended up doing is create a new KeyContainer name based off of the current DateTime (DateTime.Now.Ticks.ToString()) whenever I need to create a new key and save the container name and public key to the database. Also, whenever I create a new key I would do the following:

public static string ConvertToNewKey(string oldPrivateKey)
{

    // get the current container name from the database...

    rsa.PersistKeyInCsp = false;
    rsa.Clear();
    rsa = null;

    string privateKey = AssignNewKey(true); // create the new public key and container name and write them to the database...

       // re-encrypt existing data to use the new keys and write to database...

    return privateKey;
}
public static string AssignNewKey(bool ReturnPrivateKey){
     string containerName = DateTime.Now.Ticks.ToString();
     // create the new key...
     // saves container name and public key to database...
     // and returns Private Key XML.
}

before creating the new key.

Java. Implicit super constructor Employee() is undefined. Must explicitly invoke another constructor

Any constructor for any class as you know creates an object. So, the constructor should contain proper initialization code for its class. But if you have some class which extends another one (lets call it "parent") then constructor for the class cannot contain all the code needed for the initialization by definition (for example, you cannot define private fields of the parent). That's why constructor of the class has to call constructor of its parent. If you do not call it explicitly then the default parent constructor is called (which is without any parameter).

So, in your case, you can either implement default constructor in parent or directly call any constructor in the class.

How can I run multiple curl requests processed sequentially?

Another crucial method not mentioned here is using the same TCP connection for multiple HTTP requests, and exactly one curl command for this.

This is very useful to save network bandwidth, client and server resources, and overall the need of using multiple curl commands, as curl by default closes the connection when end of command is reached.

Keeping the connection open and reusing it is very common for standard clients running a web-app.

Starting curl version 7.36.0, the --next or -: command-line option allows to chain multiple requests, and usable both in command-line and scripting.

For example:

  • Sending multiple requests on the same TCP connection:

curl http://example.com/?update_=1 -: http://example.com/foo

  • Sending multiple different HTTP requests on the same connection:

curl http://example.com/?update_=1 -: -d "I am posting this string" http://example.com/?update_=2

  • Sending multiple HTTP requests with different curl options for each request:

curl -o 'my_output_file' http://example.com/?update_=1 -: -d "my_data" -s -m 10 http://example.com/foo -: -o /dev/null http://example.com/random

From the curl manpage:

-:, --next

Tells curl to use a separate operation for the following URL and associated options. This allows you to send several URL requests, each with their own specific options, for example, such as different user names or custom requests for each.

-:, --next will reset all local options and only global ones will have their values survive over to the operation following the -:, --next instruction. Global options include -v, --verbose, --trace, --trace-ascii and --fail-early.

For example, you can do both a GET and a POST in a single command line:

curl www1.example.com --next -d postthis www2.example.com

Added in 7.36.0.

C pass int array pointer as parameter into a function

Maybe you were trying to do this?

#include <stdio.h>

int func(int * B){

    /* B + OFFSET = 5 () You are pointing to the same region as B[OFFSET] */
    *(B + 2) = 5;
}

int main(void) {

    int B[10];

    func(B);

    /* Let's say you edited only 2 and you want to show it. */
    printf("b[0] = %d\n\n", B[2]);

    return 0;
}

How can I position my div at the bottom of its container?

Create another container div for the elements above #copyright. Just above copyright add a new div: <div style="clear:both;"></div> It will force the footer to be under everything else, just like in the case of using relative positioning (bottom:0px;).

Send data from javascript to a mysql database

The other posters are correct you cannot connect to MySQL directly from javascript. This is because JavaScript is at client side & mysql is server side.

So your best bet is to use ajax to call a handler as quoted above if you can let us know what language your project is in we can better help you ie php/java/.net

If you project is using php then the example from Merlyn is a good place to start, I would personally use jquery.ajax() to cut down you code and have a better chance of less cross browser issues.

http://api.jquery.com/jQuery.ajax/

How do you append an int to a string in C++?

You also try concatenate player's number with std::string::push_back :

Example with your code:

int i = 4;
string text = "Player ";
text.push_back(i + '0');
cout << text;

You will see in console:

Player 4

Rails where condition using NOT NIL

Not sure of this is helpful but this what worked for me in Rails 4

Foo.where.not(bar: nil)

SQL - Update multiple records in one query

in my case I have to update the records which are more than 1000, for this instead of hitting the update query each time I preferred this,

   UPDATE mst_users 
   SET base_id = CASE user_id 
   WHEN 78 THEN 999 
   WHEN 77 THEN 88 
   ELSE base_id END WHERE user_id IN(78, 77)

78,77 are the user Ids and for those user id I need to update the base_id 999 and 88 respectively.This works for me.

Create dynamic variable name

This is not possible, it will give you a compile time error,

You can use array for this type of requirement .

For your Reference :

http://msdn.microsoft.com/en-us/library/aa288453%28v=vs.71%29.aspx

Is it possible to set a custom font for entire of application?

Since the release of Android Oreo and its support library (26.0.0) you can do this easily. Refer to this answer in another question.

Basically your final style will look like this:

<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
   <item name="fontFamily">@font/your_font</item> <!-- target android sdk versions < 26 and > 14 -->
</style>

Why use the 'ref' keyword when passing an object?

You need to distinguish between "passing a reference by value", and "passing a parameter/argument by reference".

I've written a reasonably long article on the subject to avoid having to write carefully each time this comes up on newsgroups

jQuery set radio button

You can simply use:

$("input[name='cols']").click();

AngularJS POST Fails: Response for preflight has invalid HTTP status code 404

For a Node.js app, in the server.js file before registering all of my own routes, I put the code below. It sets the headers for all responses. It also ends the response gracefully if it is a pre-flight "OPTIONS" call and immediately sends the pre-flight response back to the client without "nexting" (is that a word?) down through the actual business logic routes. Here is my server.js file. Relevant sections highlighted for Stackoverflow use.

// server.js

// ==================
// BASE SETUP

// import the packages we need
var express    = require('express');
var app        = express();
var bodyParser = require('body-parser');
var morgan     = require('morgan');
var jwt        = require('jsonwebtoken'); // used to create, sign, and verify tokens

// ====================================================
// configure app to use bodyParser()
// this will let us get the data from a POST
app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

// Logger
app.use(morgan('dev'));

// -------------------------------------------------------------
// STACKOVERFLOW -- PAY ATTENTION TO THIS NEXT SECTION !!!!!
// -------------------------------------------------------------

//Set CORS header and intercept "OPTIONS" preflight call from AngularJS
var allowCrossDomain = function(req, res, next) {
    res.header('Access-Control-Allow-Origin', '*');
    res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
    res.header('Access-Control-Allow-Headers', 'Content-Type');
    if (req.method === "OPTIONS") 
        res.send(200);
    else 
        next();
}

// -------------------------------------------------------------
// STACKOVERFLOW -- END OF THIS SECTION, ONE MORE SECTION BELOW
// -------------------------------------------------------------


// =================================================
// ROUTES FOR OUR API

var route1 = require("./routes/route1");
var route2 = require("./routes/route2");
var error404 = require("./routes/error404");


// ======================================================
// REGISTER OUR ROUTES with app

// -------------------------------------------------------------
// STACKOVERFLOW -- PAY ATTENTION TO THIS NEXT SECTION !!!!!
// -------------------------------------------------------------

app.use(allowCrossDomain);

// -------------------------------------------------------------
//  STACKOVERFLOW -- OK THAT IS THE LAST THING.
// -------------------------------------------------------------

app.use("/api/v1/route1/", route1);
app.use("/api/v1/route2/", route2);
app.use('/', error404);

// =================
// START THE SERVER

var port = process.env.PORT || 8080;        // set our port
app.listen(port);
console.log('API Active on port ' + port);

"Faceted Project Problem (Java Version Mismatch)" error message

In Spring STS, Right click the project & select "Open Project", This provision do the necessary action on the background & bring the project back to work space.

Thanks & Regards Vengat Maran

How to set Java classpath in Linux?

You have to use ':' colon instead of ';' semicolon.

As it stands now you try to execute the jar file which has not the execute bit set, hence the Permission denied.

And the variable must be CLASSPATH not classpath.

How to force garbage collection in Java?

Using the Java™ Virtual Machine Tool Interface (JVM TI), the function

jvmtiError ForceGarbageCollection(jvmtiEnv* env)

will "Force the VM to perform a garbage collection." The JVM TI is part of the JavaTM Platform Debugger Architecture (JPDA).

How to create cron job using PHP?

In the same way you are trying to run cron.php, you can run another PHP script. You will have to do so via the CLI interface though.

#!/usr/bin/env php
<?php
# This file would be say, '/usr/local/bin/run.php'
// code
echo "this was run from CRON";

Then, add an entry to the crontab:

* * * * * /usr/bin/php -f /usr/local/bin/run.php &> /dev/null

If the run.php script had executable permissions, it could be listed directly in the crontab, without the /usr/bin/php part as well. The 'env php' part, in the script, would find the appropriate program to actually run the PHP code. So, for the 'executable' version - add executable permission to the file:

chmod +x /usr/local/bin/run.php

and then, add the following entry into crontab:

* * * * * /usr/local/bin/run.php &> /dev/null

How do you write to a folder on an SD card in Android?

Found the answer here - http://mytechead.wordpress.com/2014/01/30/android-create-a-file-and-write-to-external-storage/

It says,

/**

* Method to check if user has permissions to write on external storage or not

*/

public static boolean canWriteOnExternalStorage() {
   // get the state of your external storage
   String state = Environment.getExternalStorageState();
   if (Environment.MEDIA_MOUNTED.equals(state)) {
    // if storage is mounted return true
      Log.v("sTag", "Yes, can write to external storage.");
      return true;
   }
   return false;
}

and then let’s use this code to actually write to the external storage:

// get the path to sdcard
File sdcard = Environment.getExternalStorageDirectory();
// to this path add a new directory path
File dir = new File(sdcard.getAbsolutePath() + "/your-dir-name/");
// create this directory if not already created
dir.mkdir();
// create the file in which we will write the contents
File file = new File(dir, "My-File-Name.txt");
FileOutputStream os = outStream = new FileOutputStream(file);
String data = "This is the content of my file";
os.write(data.getBytes());
os.close();

And this is it. If now you visit your /sdcard/your-dir-name/ folder you will see a file named - My-File-Name.txt with the content as specified in the code.

PS:- You need the following permission -

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

HttpListener Access Denied

Yes you can run HttpListener in non-admin mode. All you need to do is grant permissions to the particular URL. e.g.

netsh http add urlacl url=http://+:80/MyUri user=DOMAIN\user

Documentation is here.

How do I display the value of a Django form field in a template?

The solution proposed by Jens is correct. However, it turns out that if you initialize your ModelForm with an instance (example below) django will not populate the data:

def your_view(request):   
    if request.method == 'POST':
        form = UserDetailsForm(request.POST)
        if form.is_valid():
          # some code here   
        else:
          form = UserDetailsForm(instance=request.user)

So, I made my own ModelForm base class that populates the initial data:

from django import forms 
class BaseModelForm(forms.ModelForm):
    """
    Subclass of `forms.ModelForm` that makes sure the initial values
    are present in the form data, so you don't have to send all old values
    for the form to actually validate.
    """
    def merge_from_initial(self):
        filt = lambda v: v not in self.data.keys()
        for field in filter(filt, getattr(self.Meta, 'fields', ())):
            self.data[field] = self.initial.get(field, None)

Then, the simple view example looks like this:

def your_view(request):   if request.method == 'POST':
    form = UserDetailsForm(request.POST)
    if form.is_valid():
      # some code here   
    else:
      form = UserDetailsForm(instance=request.user)
      form.merge_from_initial()

Where does gcc look for C and C++ header files?

The set of paths where the compiler looks for the header files can be checked by the command:-

cpp -v

If you declare #include "" , the compiler first searches in current directory of source file and if not found, continues to search in the above retrieved directories.

If you declare #include <> , the compiler searches directly in those directories obtained from the above command.

Source:- http://commandlinefanatic.com/cgi-bin/showarticle.cgi?article=art026

How to convert a selection to lowercase or uppercase in Sublime Text

For others needing a key binding:

{ "keys": ["ctrl+="], "command": "upper_case" },
{ "keys": ["ctrl+-"], "command": "lower_case" }

Using print statements only to debug

A simple way to do this is to call a logging function:

DEBUG = True

def log(s):
    if DEBUG:
        print s

log("hello world")

Then you can change the value of DEBUG and run your code with or without logging.

The standard logging module has a more elaborate mechanism for this.

How to set time zone in codeigniter?

Put it in config/config.php, It will work for whole application or index.php of codeigniter.

How to instantiate a File object in JavaScript?

Update

BlobBuilder has been obsoleted see how you go using it, if you're using it for testing purposes.

Otherwise apply the below with migration strategies of going to Blob, such as the answers to this question.

Use a Blob instead

As an alternative there is a Blob that you can use in place of File as it is what File interface derives from as per W3C spec:

interface File : Blob {
    readonly attribute DOMString name;
    readonly attribute Date lastModifiedDate;
};

The File interface is based on Blob, inheriting blob functionality and expanding it to support files on the user's system.

Create the Blob

Using the BlobBuilder like this on an existing JavaScript method that takes a File to upload via XMLHttpRequest and supplying a Blob to it works fine like this:

var BlobBuilder = window.MozBlobBuilder || window.WebKitBlobBuilder;
var bb = new BlobBuilder();

var xhr = new XMLHttpRequest();
xhr.open('GET', 'http://jsfiddle.net/img/logo.png', true);

xhr.responseType = 'arraybuffer';

bb.append(this.response); // Note: not xhr.responseText

//at this point you have the equivalent of: new File()
var blob = bb.getBlob('image/png');

/* more setup code */
xhr.send(blob);

Extended example

The rest of the sample is up on jsFiddle in a more complete fashion but will not successfully upload as I can't expose the upload logic in a long term fashion.

How do I keep CSS floats in one line?

When user reduces window size horizontally and this causes floats to stack vertically, remove the floats and on the second div (that was a float) use margin-top: -123px (your value) and margin-left: 444px (your value) to position the divs as they appeared with floats. When done this way, when the window narrows, the right-side div stays in place and disappears when page is too narrow to include it. ... which (to me) is better than having the right-side div "jump" down below the left-side div when the browser window is narrowed by the user.

How to check if a String contains another String in a case insensitive manner in Java?

Yes, this is achievable:

String s1 = "abBaCca";
String s2 = "bac";

String s1Lower = s1;

//s1Lower is exact same string, now convert it to lowercase, I left the s1 intact for print purposes if needed

s1Lower = s1Lower.toLowerCase();

String trueStatement = "FALSE!";
if (s1Lower.contains(s2)) {

    //THIS statement will be TRUE
    trueStatement = "TRUE!"
}

return trueStatement;

This code will return the String "TRUE!" as it found that your characters were contained.

Insert an element at a specific index in a list and return the updated list

The cleanest approach is to copy the list and then insert the object into the copy. On Python 3 this can be done via list.copy:

new = old.copy()
new.insert(index, value)

On Python 2 copying the list can be achieved via new = old[:] (this also works on Python 3).

In terms of performance there is no difference to other proposed methods:

$ python --version
Python 3.8.1
$ python -m timeit -s "a = list(range(1000))" "b = a.copy(); b.insert(500, 3)"
100000 loops, best of 5: 2.84 µsec per loop
$ python -m timeit -s "a = list(range(1000))" "b = a.copy(); b[500:500] = (3,)"
100000 loops, best of 5: 2.76 µsec per loop

for each loop in Objective-C for accessing NSMutable dictionary

Fast enumeration was added in 10.5 and in the iPhone OS, and it's significantly faster, not just syntactic sugar. If you have to target the older runtime (i.e. 10.4 and backwards), you'll have to use the old method of enumerating:

NSDictionary *myDict = ... some keys and values ...
NSEnumerator *keyEnum = [myDict keyEnumerator];
id key;

while ((key = [keyEnum nextObject]))
{
    id value = [myDict objectForKey:key];
    ... do work with "value" ...
}

You don't release the enumerator object, and you can't reset it. If you want to start over, you have to ask for a new enumerator object from the dictionary.

Update a local branch with the changes from a tracked remote branch

You have set the upstream of that branch

(see:

git branch -f --track my_local_branch origin/my_remote_branch
# OR (if my_local_branch is currently checked out):
$ git branch --set-upstream-to my_local_branch origin/my_remote_branch

(git branch -f --track won't work if the branch is checked out: use the second command git branch --set-upstream-to instead, or you would get "fatal: Cannot force update the current branch.")

That means your branch is already configured with:

branch.my_local_branch.remote origin
branch.my_local_branch.merge my_remote_branch

Git already has all the necessary information.
In that case:

# if you weren't already on my_local_branch branch:
git checkout my_local_branch 
# then:
git pull

is enough.


If you hadn't establish that upstream branch relationship when it came to push your 'my_local_branch', then a simple git push -u origin my_local_branch:my_remote_branch would have been enough to push and set the upstream branch.
After that, for the subsequent pulls/pushes, git pull or git push would, again, have been enough.

How to check if a socket is connected/disconnected in C#?

The best way is simply to have your client send a PING every X seconds, and for the server to assume it is disconnected after not having received one for a while.

I encountered the same issue as you when using sockets, and this was the only way I could do it. The socket.connected property was never correct.

In the end though, I switched to using WCF because it was far more reliable than sockets.

Multiple aggregations of the same column using pandas GroupBy.agg()

TLDR; Pandas groupby.agg has a new, easier syntax for specifying (1) aggregations on multiple columns, and (2) multiple aggregations on a column. So, to do this for pandas >= 0.25, use

df.groupby('dummy').agg(Mean=('returns', 'mean'), Sum=('returns', 'sum'))

           Mean       Sum
dummy                    
1      0.036901  0.369012

OR

df.groupby('dummy')['returns'].agg(Mean='mean', Sum='sum')

           Mean       Sum
dummy                    
1      0.036901  0.369012

Pandas >= 0.25: Named Aggregation

Pandas has changed the behavior of GroupBy.agg in favour of a more intuitive syntax for specifying named aggregations. See the 0.25 docs section on Enhancements as well as relevant GitHub issues GH18366 and GH26512.

From the documentation,

To support column-specific aggregation with control over the output column names, pandas accepts the special syntax in GroupBy.agg(), known as “named aggregation”, where

  • The keywords are the output column names
  • The values are tuples whose first element is the column to select and the second element is the aggregation to apply to that column. Pandas provides the pandas.NamedAgg namedtuple with the fields ['column', 'aggfunc'] to make it clearer what the arguments are. As usual, the aggregation can be a callable or a string alias.

You can now pass a tuple via keyword arguments. The tuples follow the format of (<colName>, <aggFunc>).

import pandas as pd

pd.__version__                                                                                                                            
# '0.25.0.dev0+840.g989f912ee'

# Setup
df = pd.DataFrame({'kind': ['cat', 'dog', 'cat', 'dog'],
                   'height': [9.1, 6.0, 9.5, 34.0],
                   'weight': [7.9, 7.5, 9.9, 198.0]
})

df.groupby('kind').agg(
    max_height=('height', 'max'), min_weight=('weight', 'min'),)

      max_height  min_weight
kind                        
cat          9.5         7.9
dog         34.0         7.5

Alternatively, you can use pd.NamedAgg (essentially a namedtuple) which makes things more explicit.

df.groupby('kind').agg(
    max_height=pd.NamedAgg(column='height', aggfunc='max'), 
    min_weight=pd.NamedAgg(column='weight', aggfunc='min')
)

      max_height  min_weight
kind                        
cat          9.5         7.9
dog         34.0         7.5

It is even simpler for Series, just pass the aggfunc to a keyword argument.

df.groupby('kind')['height'].agg(max_height='max', min_height='min')    

      max_height  min_height
kind                        
cat          9.5         9.1
dog         34.0         6.0       

Lastly, if your column names aren't valid python identifiers, use a dictionary with unpacking:

df.groupby('kind')['height'].agg(**{'max height': 'max', ...})

Pandas < 0.25

In more recent versions of pandas leading upto 0.24, if using a dictionary for specifying column names for the aggregation output, you will get a FutureWarning:

df.groupby('dummy').agg({'returns': {'Mean': 'mean', 'Sum': 'sum'}})
# FutureWarning: using a dict with renaming is deprecated and will be removed 
# in a future version

Using a dictionary for renaming columns is deprecated in v0.20. On more recent versions of pandas, this can be specified more simply by passing a list of tuples. If specifying the functions this way, all functions for that column need to be specified as tuples of (name, function) pairs.

df.groupby("dummy").agg({'returns': [('op1', 'sum'), ('op2', 'mean')]})

        returns          
            op1       op2
dummy                    
1      0.328953  0.032895

Or,

df.groupby("dummy")['returns'].agg([('op1', 'sum'), ('op2', 'mean')])

            op1       op2
dummy                    
1      0.328953  0.032895

rails bundle clean

If you are using Bundler 1.1 or later you can use bundle clean, just as you imagined you could. This is redundant if you're using bundle install --path (Bundler manages the location you specified with --path, so takes responsibility for removing outdated gems), but if you've used Bundler to install the gems as system gems then bundle clean --force will delete any system gems not required by your Gemfile. Blindingly obvious caveat: don't do this if you have other apps that rely on system gems that aren't in your Gemfile!

Pat Shaughnessy has a good description of bundle clean and other new additions in bundler 1.1.

Convert multidimensional array into single array

none of answers helped me, in case when I had several levels of nested arrays. the solution is almost same as @AlienWebguy already did, but with tiny difference.

function nestedToSingle(array $array)
{
    $singleDimArray = [];

    foreach ($array as $item) {

        if (is_array($item)) {
            $singleDimArray = array_merge($singleDimArray, nestedToSingle($item));

        } else {
            $singleDimArray[] = $item;
        }
    }

    return $singleDimArray;
}

test example

$array = [
        'first',
        'second',
        [
            'third',
            'fourth',
        ],
        'fifth',
        [
            'sixth',
            [
                'seventh',
                'eighth',
                [
                    'ninth',
                    [
                        [
                            'tenth'
                        ]
                    ]
                ],
                'eleventh'
            ]
        ],
        'twelfth'
    ];

    $array = nestedToSingle($array);
    print_r($array);

    //output
    array:12 [
        0 => "first"
        1 => "second"
        2 => "third"
        3 => "fourth"
        4 => "fifth"
        5 => "sixth"
        6 => "seventh"
        7 => "eighth"
        8 => "ninth"
        9 => "tenth"
        10 => "eleventh"
        11 => "twelfth"
   ]

Number to String in a formula field

i wrote a simple function for this:

Function (stringVar param)
(
    Local stringVar oneChar := '0';
    Local numberVar strLen := Length(param);
    Local numberVar index := strLen;

    oneChar = param[strLen];

    while index > 0 and oneChar = '0' do
    (
        oneChar := param[index];
        index := index - 1;
    );

    Left(param , index + 1);
)

Add class to an element in Angular 4

Here is a plunker showing how you can use it with the ngClass directive.

I'm demonstrating with divs instead of imgs though.

Template:

<ul>
      <li><div [ngClass]="{'this-is-a-class': selectedIndex == 1}" (click)="setSelected(1)"> </div></li>
      <li><div [ngClass]="{'this-is-a-class': selectedIndex == 2}" (click)="setSelected(2)"> </div></li>
      <li><div [ngClass]="{'this-is-a-class': selectedIndex == 3}" (click)="setSelected(3)"> </div></li>
</ul>

TS:

export class App {
  selectedIndex = -1;

  setSelected(id: number) {
    this.selectedIndex = id;
  }
}

At least one JAR was scanned for TLDs yet contained no TLDs

(tomcat 7.0.32) I had problems to see debug messages althought was enabling TldLocationsCache row in tomcat/conf/logging.properties file. All I could see was a warning but not what libs were scanned. Changed every loglevel tried everything no luck. Then I went rogue debug mode (=remove one by one, clean install etc..) and finally found a reason.

My webapp had a customized tomcat/webapps/mywebapp/WEB-INF/classes/logging.properties file. I copied TldLocationsCache row to this file, finally I could see jars filenames.

# To see debug messages in TldLocationsCache, uncomment the following line: org.apache.jasper.compiler.TldLocationsCache.level = FINE

How to install Openpyxl with pip

  1. https://pypi.python.org/pypi/openpyxl download zip file and unzip it on local system.
  2. go to openpyxl folder where setup.py is present.
  3. open command prompt under the same path.
  4. Run a command: python setup.py install
  5. It will install openpyxl.

Access to file download dialog in Firefox

I was facing the same issue. In our application the instance of FireFox was created by passing the DesiredCapabilities as follows

driver = new FirefoxDriver(capabilities);

Based on the suggestions by others, I did my changes as

FirefoxProfile firefoxProfile = new FirefoxProfile();     
firefoxProfile.setPreference("browser.helperApps.neverAsk.saveToDisk",
    "application/octet-stream");
driver = new FirefoxDrvier(firefoxProfile);

This served the purpose but unfortunately my other automation tests started failing. And the reason was, I have removed the capabilities which were being passed earlier.

Some more browsing on net and found an alternate way. We can set the profile itself in the desired Capabilities.

So the new working code looks like

DesiredCapabilities capabilities = DesiredCapabilities.firefox();

// add more capabilities as per your need.
FirefoxProfile firefoxProfile = new FirefoxProfile();        
firefoxProfile.setPreference("browser.helperApps.neverAsk.saveToDisk",
    "application/octet-stream");

// set the firefoxprofile as a capability
capabilities.setCapability(FirefoxDriver.PROFILE, firefoxProfile);
driver = new FirefoxDriver(capabilities);

How to use addTarget method in swift 3

In swift 3 use this -

object?.addTarget(objectWhichHasMethod, action: #selector(classWhichHasMethod.yourMethod), for: someUIControlEvents)

For example(from my code) -

self.datePicker?.addTarget(self, action:#selector(InfoTableViewCell.datePickerValueChanged), for: .valueChanged)

Just give a : after method name if you want the sender as parameter.

Take a full page screenshot with Firefox on the command-line

Update 2018-07-23

As was just pointed out in the comments, this question was about getting a screenshot from the command line. Sorry, I just read over that. So here is the correct answer:

As of Firefox 57 you can create a screenshot in headless mode like this:

firefox -screenshot https://developer.mozilla.com

Read more in the documentation.

Update 2017-06-15

As of Firefox 55 there is Firefox Screenshots as a more flexible alternative. As of Firefox 57 Screenshots can capture a full page, too.

Original answer

Since Firefox 32 there is also a full page screenshot button in the developer tools (F12). If it is not enabled go to the developer tools settings (gear button) and choose "Take a fullpage screenshot" at the "Available Toolbox Buttons" section.

developer tools toolbar source: developer.mozilla.org

By default the screenshots are saved in the download directory. This works similar to screenshot --fullpage in the toolbar.

Java: is there a map function?

This is another functional lib with which you may use map: http://code.google.com/p/totallylazy/

sequence(1, 2).map(toString); // lazily returns "1", "2"