Programs & Examples On #Gal

Global Address List (GAL) is a directory service within the Microsoft Exchange email system.

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 ;)


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

How do I install the Nuget provider for PowerShell on a unconnected machine so I can install a nuget package from the PS command line?

Try this:

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

Install-PackageProvider NuGet -Force

Set-PSRepository PSGallery -InstallationPolicy Trusted

what is an illegal reflective access

There is an Oracle article I found regarding Java 9 module system

By default, a type in a module is not accessible to other modules unless it’s a public type and you export its package. You expose only the packages you want to expose. With Java 9, this also applies to reflection.

As pointed out in, the differences between the AccessibleObject#setAccessible for JDK8 and JDK9 are instructive. Specifically, JDK9 added

This method may be used by a caller in class C to enable access to a member of declaring class D if any of the following hold:

  • C and D are in the same module.
  • The member is public and D is public in a package that the module containing D exports to at least the module containing C.
  • The member is protected static, D is public in a package that the module containing D exports to at least the module containing C, and C is a subclass of D.
  • D is in a package that the module containing D opens to at least the module containing C. All packages in unnamed and open modules are open to all modules and so this method always succeeds when D is in an unnamed or open module.

which highlights the significance of modules and their exports (in Java 9)

Unable to compile simple Java 10 / Java 11 project with Maven

Alright so for me nothing worked.
I was using spring boot with hibernate. The spring boot version was ~2.0.1 and I would keep get this error and null pointer exception upon compilation. The issue was with hibernate that needed a version bump. But after that I had some other issues that seemed like the annotation processor was not recognised so I decided to just bump spring from 2.0.1 to 2.1.7-release and everything worked as expected.

You still need to add the above plugin tough
Hope it helps!

After Spring Boot 2.0 migration: jdbcUrl is required with driverClassName

This happened to me because I was using:


When I replaced url by jdbc-url then it worked:


Dart SDK is not configured

I recently faced this issue on my MAC device when I was running flutter project on Android Studio

Steps to fix this.

  1. install dart on MAC os using brew (

brew tap dart-lang/dart

brew install dart

  1. run

brew info dart

  1. It will give you output something like this

Please note the path to the Dart SDK:/usr/local/opt/dart/libexec

paste the Dart SDK path in Android Studio Settings

java.lang.IllegalStateException: Only fullscreen opaque activities can request orientation

it seems when target sdk is pie (api level 28.0) and windowIsTranslucent is true

<item name="android:windowIsTranslucent">true</item>

and you try to access orientation. problem comes with android oreo 8.0 (api level 26) there are two ways to solve this

  1. remove the orientation
  2. or set windowIsTranslucent to false

if you are setting orientation in manifest like this


or in activity class like this


remove form both places.

and observed when u set windowIsTranslucent to true, it takes orientation from parent activity.

Android 8.0: java.lang.IllegalStateException: Not allowed to start service Intent

I got solution. For pre-8.0 devices, you have to just use startService(), but for post-7.0 devices, you have to use startForgroundService(). Here is sample for code to start service.

        context.startForegroundService(new Intent(context, ServedService.class));
    } else {
        context.startService(new Intent(context, ServedService.class));

And in service class, please add the code below for notification:

public void onCreate() {
    startForeground(1,new Notification());

Where O is Android version 26.

If you don't want your service to run in Foreground and want it to run in background instead, post Android O you must bind the service to a connection like below:

Intent serviceIntent = new Intent(context, ServedService.class);
context.bindService(serviceIntent, new ServiceConnection() {
     public void onServiceConnected(ComponentName name, IBinder service) {
         //retrieve an instance of the service here from the IBinder returned 
         //from the onBind method to communicate with 

     public void onServiceDisconnected(ComponentName name) {

Add class to an element in Angular 4

Use [ngClass] and conditionally apply class based on the id.

In your HTML file:

    <img [ngClass]="{'this-is-a-class': id === 1 }" id="1"  
         src="../../assets/images/1.jpg" (click)="addClass(id=1)"/>
    <img [ngClass]="{'this-is-a-class': id === 2 }" id="2"  
         src="../../assets/images/2.png" (click)="addClass(id=2)"/>

In your TypeScript file:

addClass(id: any) { = id;

Returning JSON object as response in Spring Boot

If you need to return a JSON object using a String, then the following should work:

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.http.ResponseEntity;

public class StudentController {

    public ResponseEntity<JsonNode> get() throws JsonProcessingException {
        ObjectMapper mapper = new ObjectMapper();
        JsonNode json = mapper.readTree("{\"id\": \"132\", \"name\": \"Alice\"}");
        return ResponseEntity.ok(json);

Get Path from another app (WhatsApp)

Using the code example below will return to you the bitmap :


After that you all know what you have to do.

Android Room - simple select query - Cannot access database on the main thread

Just do the database operations in a separate Thread. Like this (Kotlin):

Thread {
   //Do your database´s operations here

Jersey stopped working with InjectionManagerFactory not found

Jersey 2.26 and newer are not backward compatible with older versions. The reason behind that has been stated in the release notes:

Unfortunately, there was a need to make backwards incompatible changes in 2.26. Concretely jersey-proprietary reactive client API is completely gone and cannot be supported any longer - it conflicts with what was introduced in JAX-RS 2.1 (that's the price for Jersey being "spec playground..").

Another bigger change in Jersey code is attempt to make Jersey core independent of any specific injection framework. As you might now, Jersey 2.x is (was!) pretty tightly dependent on HK2, which sometimes causes issues (esp. when running on other injection containers. Jersey now defines it's own injection facade, which, when implemented properly, replaces all internal Jersey injection.

As for now one should use the following dependencies:




compile 'org.glassfish.jersey.core:jersey-common:2.26'
compile 'org.glassfish.jersey.inject:jersey-hk2:2.26'

Load json from local file with http.get() in angular 2

You have to change

loadNavItems() {
        this.navItems = this.http.get("../data/navItems.json");


loadNavItems() {
        this.navItems = this.http.get("../data/navItems.json")
                        .map(res => res.json())
                        .do(data => console.log(data));
                        //This is optional, you can remove the last line 
                        // if you don't want to log loaded json in 
                        // console.

Because this.http.get returns an Observable<Response> and you don't want the response, you want its content.

The console.log shows you an observable, which is correct because navItems contains an Observable<Response>.

In order to get data properly in your template, you should use async pipe.

<app-nav-item-comp *ngFor="let item of navItems | async" [item]="item"></app-nav-item-comp>

This should work well, for more informations, please refer to HTTP Client documentation

Spring boot: Unable to start embedded Tomcat servlet container

You need to add the tomcat dependency in your pom


Visual Studio 2017 error: Unable to start program, An operation is not legal in the current state

For me, the solution (workaround) is to turn off JavaScript debugging on Chrome, which I believe is a new feature introduced in VS 2017.

Go to Tools > Options > Debugging > General and turn off the setting for Enable JavaScript Debugging for ASP.NET (Chrome and IE).

VS2017 Disable JS Debugging

This is a known issue already, and seems to have an investigation underway.

Full information about JS debugging in VS 2017 here:

FileProvider - IllegalArgumentException: Failed to find configured root

Hello Friends Try This

In this Code

1) How to Declare 2 File Provider in Manifest.

2) First Provider for file Download

3) second Provider used for camera and gallary


            android:resource="@xml/provider_paths" />


<?xml version="1.0" encoding="utf-8"?>
<files-path name="apks" path="." />

Second Provider

            android:resource="@xml/file_path" />


<?xml version="1.0" encoding="utf-8"?>
<external-path name="storage/emulated/0" path="."/>


Create Class MyFileProvider (only Create class no any method declare)

When you used File Provider used (.fileprovider) this name and you used for image (.provider) used this.

IF any one Problem to understand this code You can Contact on [email protected] i will help you.

Tomcat: java.lang.IllegalArgumentException: Invalid character found in method name. HTTP method names must be tokens

I received this exception unrelated to any TLS issues. In my case the Content-Length header value did not match the body length.

Tomcat 8 is not able to handle get request with '|' in query parameters?

The parameter tomcat.util.http.parser.HttpParser.requestTargetAllow is deprecated since Tomcat 8.5: tomcat official doc.

You can use relaxedQueryChars / relaxedPathChars in the connectors definition to allow these chars: tomcat official doc.

Bootstrap 4 img-circle class not working

In Bootstrap 4 it was renamed to .rounded-circle

Usage :

<div class="col-xs-7">
    <img src="img/gallery2.JPG" class="rounded-circle" alt="HelPic>

See migration docs from bootstrap.

Default FirebaseApp is not initialized

One of the reason of this happening could be to forgetting adding android.permission.INTERNET permissions in AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET" />

Unable to find a @SpringBootConfiguration when doing a JpaTest

import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureWebMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

public class RepoTest {

    private ThingShiftDetailsRepository thingShiftDetailsRepo;

    public void findThingShiftDetails() {
            ShiftDetails details = new ShiftDetails();


            ShiftDetails dbDetails = thingShiftDetailsRepo.findByThingId(1);

Above annotations worked well for me. I am using spring boot with JPA.

Selenium using Java - The path to the driver executable must be set by the webdriver.gecko.driver system property

I use from selenium-java-3.141.59 in windows 10 and solved my problem with this code:

System.setProperty("webdriver.gecko.driver", "C:\\gecko\\geckodriver.exe");
System.setProperty("webdriver.firefox.bin","C:\\Program Files\\Mozilla Firefox\\firefox.exe");
WebDriver driver = new FirefoxDriver();

Getting "Cannot call a class as a function" in my React Project

In file MyComponent.js

export default class MyComponent extends React.Component {

I put some function related to that component:

export default class MyComponent extends React.Component {

export myFunction() {

and then in another file imported that function:

import myFunction from './MyComponent'
myFunction() // => bang! "Cannot call a class as a function"

Can you spot the problem?

I forgot the curly braces, and imported MyComponent under name myFunction!

So, the fix was:

import {myFunction} from './MyComponent'

Python & Matplotlib: Make 3D plot interactive in Jupyter Notebook

For 3-D visualization pythreejs is the best way to go probably in the notebook. It leverages the interactive widget infrastructure of the notebook, so connection between the JS and python is seamless.

A more advanced library is bqplot which is a d3-based interactive viz library for the iPython notebook, but it only does 2D

java.lang.IllegalArgumentException: No converter found for return value of type

The issue occurred in my case because spring framework couldn't fetch the properties of nested objects. Getters/Setters is one way of solving. Making the properties public is another quick and dirty solution to validate if this is indeed the problem.

How to set the max size of upload file

You need to set the multipart.maxFileSize and multipart.maxRequestSize parameters to higher values than the default. This can be done in your spring boot configuration yml files. For example, adding the following to application.yml will allow users to upload 10Mb files:

    maxFileSize: 10Mb
    maxRequestSize: 10Mb

If the user needs to be able to upload multiple files in a single request and they may total more than 10Mb, then you will need to configure multipart.maxRequestSize to a higher value:

    maxFileSize: 10Mb
    maxRequestSize: 100Mb


Unable to get provider

Go to android studio setting (by pressing Ctrl+Alt+S in windows), search for Instant Run and uncheck Enable Instant Run.

By disabling Instant Run and running your application again, problem will be resolved.

Unable to capture screenshot. Prevented by security policy. Galaxy S6. Android 6.0

Go to Phone Settings --> Developer Options --> Simulate Secondary Displays and turn it to None. If you don't see Developer Options in the settings menu (it should be at the bottom, go Settings ==> About phone and tap on the Build number a lot of times)

Your configuration specifies to merge with the <branch name> from the remote, but no such ref was fetched.?

In my case, i had deleted the original branch from which my current branch derived from. So in the .git/config file i had:

[branch "simil2.1.12"]
    remote = origin
    merge = refs/heads/simil2.0.5
    rebase = false

the simil2.0.5 was deleted. I replaced it with the same branch name:

[branch "simil2.1.12"]
    remote = origin
    merge = refs/heads/simil2.1.12
    rebase = false

and it worked

Failed to load ApplicationContext (with annotation)

Your test requires a ServletContext: add @WebIntegrationTest

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

...or look here for other options:

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

Hide "NFC Tag type not supported" error on Samsung Galaxy devices

Before Android 4.4

What you are trying to do is simply not possible from an app (at least not on a non-rooted/non-modified device). The message "NFC tag type not supported" is displayed by the Android system (or more specifically the NFC system service) before and instead of dispatching the tag to your app. This means that the NFC system service filters MIFARE Classic tags and never notifies any app about them. Consequently, your app can't detect MIFARE Classic tags or circumvent that popup message.

On a rooted device, you may be able to bypass the message using either

  1. Xposed to modify the behavior of the NFC service, or
  2. the CSC (Consumer Software Customization) feature configuration files on the system partition (see /system/csc/. The NFC system service disables the popup and dispatches MIFARE Classic tags to apps if the CSC feature <CscFeature_NFC_EnableSecurityPromptPopup> is set to any value but "mifareclassic" or "all". For instance, you could use:


    You could add this entry to, for instance, the file "/system/csc/others.xml" (within the section <FeatureSet> ... </FeatureSet> that already exists in that file).

Since, you asked for the Galaxy S6 (the question that you linked) as well: I have tested this method on the S4 when it came out. I have not verified if this still works in the latest firmware or on other devices (e.g. the S6).

Since Android 4.4

This is pure guessing, but according to this (link no longer available), it seems that some apps (e.g. NXP TagInfo) are capable of detecting MIFARE Classic tags on affected Samsung devices since Android 4.4. This might mean that foreground apps are capable of bypassing that popup using the reader-mode API (see NfcAdapter.enableReaderMode) possibly in combination with NfcAdapter.FLAG_READER_SKIP_NDEF_CHECK.

NPM stuck giving the same error EISDIR: Illegal operation on a directory, read at error (native)

In my case these steps solved my problem:

  1. terminating npm process (CTRL + C)
  2. deleting entire folder
  3. creating new one
  4. running npm again

configuring project ':app' failed to find Build Tools revision

I had c++ codes in my project but i didn't have NDK installed, installing it solved the problem

Changing fonts in ggplot2

Late to the party, but this might be of interest for people looking to add custom fonts to their ggplots inside a shiny app on

You can:

  1. Place custom font in www directory: e.g. IndieFlower.ttf from here
  2. Follow the steps from here

This leads to the following upper section inside the app.R file:

file.copy("www/IndieFlower.ttf", "~/.fonts")
system('fc-cache -f ~/.fonts')

A full example app can be found here.

Content type 'application/x-www-form-urlencoded;charset=UTF-8' not supported for @RequestBody MultiValueMap

Simply removing @RequestBody annotation solves the problem (tested on Spring Boot 2):

public class MyController {

    public void method(@Valid RequestDto dto) {
       // method body ...

In android how to set navigation drawer header image and name programmatically in class file?

If you're using bindings you can do

val headerView = binding.navView.getHeaderView(0)
val headerBinding = NavDrawerHeaderBinding.bind(headerView)
headerBinding.textView.text = "Your text here"

How to return JSON data from spring Controller using @ResponseBody

Add the below dependency to your pom.xml:


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 response as String using retrofit without using GSON or any other library in android

** Update ** A scalars converter has been added to retrofit that allows for a String response with less ceremony than my original answer below.

Example interface --

public interface GitHubService {
    Call<String> listRepos(@Path("user") String user);

Add the ScalarsConverterFactory to your retrofit builder. Note: If using ScalarsConverterFactory and another factory, add the scalars factory first.

Retrofit retrofit = new Retrofit.Builder()
    // add other factories here, if needed.

You will also need to include the scalars converter in your gradle file --

implementation 'com.squareup.retrofit2:converter-scalars:2.1.0'

--- Original Answer (still works, just more code) ---

I agree with @CommonsWare that it seems a bit odd that you want to intercept the request to process the JSON yourself. Most of the time the POJO has all the data you need, so no need to mess around in JSONObject land. I suspect your specific problem might be better solved using a custom gson TypeAdapter or a retrofit Converter if you need to manipulate the JSON. However, retrofit provides more the just JSON parsing via Gson. It also manages a lot of the other tedious tasks involved in REST requests. Just because you don't want to use one of the features, doesn't mean you have to throw the whole thing out. There are times you just want to get the raw stream, so here is how to do it -

First, if you are using Retrofit 2, you should start using the Call API. Instead of sending an object to convert as the type parameter, use ResponseBody from okhttp --

public interface GitHubService {
    Call<ResponseBody> listRepos(@Path("user") String user);

then you can create and execute your call --

GitHubService service = retrofit.create(GitHubService.class);
Call<ResponseBody> result = service.listRepos(username);
result.enqueue(new Callback<ResponseBody>() {
    public void onResponse(Response<ResponseBody> response) {
        try {
        } catch (IOException e) {

    public void onFailure(Throwable t) {

Note The code above calls string() on the response object, which reads the entire response into a String. If you are passing the body off to something that can ingest streams, you can call charStream() instead. See the ResponseBody docs.

Mapping list in Yaml to list of objects in Spring Boot

I had much issues with this one too. I finally found out what's the final deal.

Referring to @Gokhan Oner answer, once you've got your Service class and the POJO representing your object, your YAML config file nice and lean, if you use the annotation @ConfigurationProperties, you have to explicitly get the object for being able to use it. Like :

@ConfigurationProperties(prefix = "available-payment-channels-list")
//@Configuration  <-  you don't specificly need this, instead you're doing something else
public class AvailableChannelsConfiguration {

    private String xyz;
    //initialize arraylist
    private List<ChannelConfiguration> channelConfigurations = new ArrayList<>();

    public AvailableChannelsConfiguration() {
        for(ChannelConfiguration current : this.getChannelConfigurations()) {
            System.out.println(current.getName()); //TADAAA

    public List<ChannelConfiguration> getChannelConfigurations() {
        return this.channelConfigurations;

    public static class ChannelConfiguration {
        private String name;
        private String companyBankAccount;


And then here you go. It's simple as hell, but we have to know that we must call the object getter. I was waiting at initialization, wishing the object was being built with the value but no. Hope it helps :)

READ_EXTERNAL_STORAGE permission for Android

Step1: add permission on android manifest.xml

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

Step2: onCreate() method

int permissionCheck = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);

    if (permissionCheck != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_MEDIA);
    } else {

Step3: override onRequestPermissionsResult method to get callback

public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
            if ((grantResults.length > 0) && (grantResults[0] == PackageManager.PERMISSION_GRANTED)) {


Note: readDataExternal() is method to get data from external storage.


Instagram API - How can I retrieve the list of people a user is following on Instagram

Here's a way to get the list of people a user is following with just a browser and some copy-paste (A pure javascript solution based on Deep Seeker's answer):

  1. Get the user's id (In a browser, navigate to and look for response -> graphql -> user -> id [from Deep Seeker's answer])

  2. Open another browser window

  3. Open the browser console and paste this in it

    options = {
        userId: your_user_id,
        list: 1 //1 for following, 2 for followers

  4. change to your user id and hit enter

  5. paste this in the console and hit enter

    `` + encodeURIComponent(JSON.stringify({
            "id": options.userId,
            "include_reel": true,
            "fetch_mutual": true,
            "first": 50

  6. Navigate to the outputted link

(This sets up the headers for the http request. If you try to run the script on a page where this isn't open, it won't work.)

  1. In the console for the page you just opened, paste this and hit enter
    let config = {
      followers: {
        hash: 'c76146de99bb02f6415203be841dd25a',
        path: 'edge_followed_by'
      following: {
        hash: 'd04b0a864b4b54837c0d870b0e77e076',
        path: 'edge_follow'
    var allUsers = [];
    function getUsernames(data) {
        var userBatch = => element.node.username);
    async function makeNextRequest(nextCurser, listConfig) {
        var params = {
            "id": options.userId,
            "include_reel": true,
            "fetch_mutual": true,
            "first": 50
        if (nextCurser) {
            params.after = nextCurser;
        var requestUrl = `` + listConfig.hash + `&variables=` + encodeURIComponent(JSON.stringify(params));
        var xhr = new XMLHttpRequest();
        xhr.onload = function(e) {
            var res = JSON.parse(xhr.response);
            var userData =[listConfig.path].edges;
            var curser = "";
            try {
                curser =[listConfig.path].page_info.end_cursor;
            } catch {
            var users = [];
            if (curser) {
                makeNextRequest(curser, listConfig);
            } else {
                var printString =""
                allUsers.forEach(item => printString = printString + item + "\n");
   "GET", requestUrl);
    if (options.list === 1) {
        makeNextRequest("", config.following);
    } else if (options.list === 2) {
        makeNextRequest("", config.followers);

After a few seconds it should output the list of users your user is following.

Ignore duplicates when producing map using streams

I have encountered such a problem when grouping object, i always resolved them by a simple way: perform a custom filter using a java.util.Set to remove duplicate object with whatever attribute of your choice as bellow

Set<String> uniqueNames = new HashSet<>();
Map<String, String> phoneBook = people
                  .filter(person -> person != null && !uniqueNames.add(person.getName()))
                  .collect(toMap(Person::getName, Person::getAddress));

Hope this helps anyone having the same problem !

Slack URL to open a channel from browser

Referencing a channel within a conversation

To create a clickable reference to a channel in a Slack conversation, just type # followed by the channel name. For example: #general.

# mention of a channel

To grab a link to a channel through the Slack UI

To share the channel URL externally, you can grab its link by control-clicking (Mac) or right-clicking (Windows) on the channel name:

grabbing a channel's URL

The link would look like this:

Note that this link doesn't change even if you change the name of the channel. So, it is better to use this link rather than the one based on channel's name.

To compose a URL for a channel based on channel name<channel_name>

Opening the above URL from a browser would launch the Slack client (if available) or open the slack channel on the browser itself.

To compose a URL for a direct message (DM) channel to a user<username>

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

@Query("SELECT DISTINCT name FROM people WHERE name NOT IN (:names)")
List<String> findNonReferencedNames(@Param("names") List<String> names);

Differences between arm64 and aarch64

It seems that ARM64 was created by Apple and AARCH64 by the others, most notably GNU/GCC guys.

After some googling I found this link:

The LLVM 64-bit ARM64/AArch64 Back-Ends Have Merged

So it makes sense, iPad calls itself ARM64, as Apple is using LLVM, and Edge uses AARCH64, as Android is using GNU GCC toolchain.

JsonParseException : Illegal unquoted character ((CTRL-CHAR, code 10)



See javadoc:

 * Feature that determines whether parser will allow
 * JSON Strings to contain unescaped control characters
 * (ASCII characters with value less than 32, including
 * tab and line feed characters) or not.
 * If feature is set false, an exception is thrown if such a
 * character is encountered.
 * Since JSON specification requires quoting for all control characters,
 * this is a non-standard feature, and as such disabled by default.

Old option JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS was deprecated since 2.10.

Please see also github thread.

YAML mapping values are not allowed in this context

This is valid YAML:

 - name: A
   schedule: "0 0/5 * 1/1 * ? *"
   type: mongodb.cluster
     host: mongodb://localhost:27017/admin?replicaSet=rs
     minSecondaries: 2
     minOplogHours: 100
     maxSecondaryDelay: 120
 - name: B
   schedule: "0 0/5 * 1/1 * ? *"
   type: mongodb.cluster
     host: mongodb://localhost:27017/admin?replicaSet=rs
     minSecondaries: 2
     minOplogHours: 100
     maxSecondaryDelay: 120

Note, that every '-' starts new element in the sequence. Also, indentation of keys in the map should be exactly same.

Simple line plots using seaborn

It's possible to get this done using seaborn.lineplot() but it involves some additional work of converting numpy arrays to pandas dataframe. Here's a complete example:

# imports
import seaborn as sns
import numpy as np
import pandas as pd

# inputs
In [41]: num = np.array([1, 2, 3, 4, 5])
In [42]: sqr = np.array([1, 4, 9, 16, 25])

# convert to pandas dataframe
In [43]: d = {'num': num, 'sqr': sqr}
In [44]: pdnumsqr = pd.DataFrame(d)

# plot using lineplot
In [45]: sns.set(style='darkgrid')
In [46]: sns.lineplot(x='num', y='sqr', data=pdnumsqr)
Out[46]: <matplotlib.axes._subplots.AxesSubplot at 0x7f583c05d0b8>

And we get the following plot:

square plot

Android Studio - Device is connected but 'offline'

  • Restart adb by issuing these commands in cmd

    adb kill-server to kill existing adb session

    followed by adb start-server to start a new adb session
  • Disable and re-enable USB debugging on the phone and accept RSA fingerprints if asked by phone
  • Rebooting the phone if it still doesn't work.

If all above don't solve your problem, you may try delete environment variable named "ANDROID_SDK_HOME". It really solved my problem. Hope it Help you!

Android Push Notifications: Icon not displaying in notification, white square shown instead

Finally I've got the solution for this issue.

This issue occurs only when the app is not at all running. (neither in the background nor in the foreground). When the app runs on either foreground or background the notification icon is displayed properly.(not the white square)

So what we've to set is the same configuration for notification icon in Backend APIs as that of Frontend.

In the frontend we've used React Native and for push notification we've used react-native-fcm npm package.

FCM.on("notification", notif => {
       body: notif.fcm.body,
       title: notif.fcm.title,
       big_text: notif.fcm.body,
       priority: "high",
       large_icon: "notification_icon", // notification icon
       icon: "notification_icon",
       show_in_foreground: true,
       color: '#8bc34b',
       vibrate: 300,
       lights: true,
       status: notif.status

We've used fcm-push npm package using Node.js as a backend for push notification and set the payload structure as follows.

  to: '/topics/user', // required
  data: {
    message: 'test message',
    title: 'test title'
  notification: {
    title: 'test title',
    body: 'test message',
    icon : 'notification_icon', // same name as mentioned in the front end
    color : '#8bc34b',
    click_action : "BROADCAST"

What it basically searches for the notification_icon image stored locally in our Android system.

How to inject a Map using the @Value Spring Annotation?

Here is how we did it. Two sample classes as follow:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.kafka.annotation.EnableKafka;
public class KafkaContainerConfig {

    protected KafkaConsumerProperties kafkaConsumerProperties;

    public ConsumerFactory<String, String> consumerFactory() {
        return new DefaultKafkaConsumerFactory<>(kafkaConsumerProperties.getKafkaConsumerConfig());

public class KafkaConsumerProperties {
    protected Map<String, Object> kafkaConsumerConfig = new HashMap<>();

    public Map<String, Object> getKafkaConsumerConfig() {
        return (kafkaConsumerConfig);

To provide the kafkaConsumer config from a properties file, you can use: mapname[key]=value

kafkaConsumerConfig[bootstrap.servers]=localhost:9092, localhost:9093, localhost:9094

To provide the kafkaConsumer config from a yaml file, you can use "[key]": value In application.yml file:

  "[bootstrap.servers]": localhost:9092, localhost:9093, localhost:9094
  "[]": test-consumer-group-local
  "[value.deserializer]": org.apache.kafka.common.serialization.StringDeserializer
  "[key.deserializer]": org.apache.kafka.common.serialization.StringDeserializer

Unknown URL content://downloads/my_downloads

I got the same issue and after a lot of time spent on the search I found the solution

Just change your method especially // DownloadsProvider part



@SuppressLint("NewApi") public static String getPath(final Context context, final Uri uri) {

    final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;

    // DocumentProvider
    if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
        // ExternalStorageProvider
        if (isExternalStorageDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            // This is for checking Main Memory
            if ("primary".equalsIgnoreCase(type)) {
                if (split.length > 1) {
                    return Environment.getExternalStorageDirectory() + "/" + split[1];
                } else {
                    return Environment.getExternalStorageDirectory() + "/";
                // This is for checking SD Card
            } else {
                return "storage" + "/" + docId.replace(":", "/");

        // DownloadsProvider
        else if (isDownloadsDocument(uri)) {
            String fileName = getFilePath(context, uri);
            if (fileName != null) {
                return Environment.getExternalStorageDirectory().toString() + "/Download/" + fileName;

            String id = DocumentsContract.getDocumentId(uri);
            if (id.startsWith("raw:")) {
                id = id.replaceFirst("raw:", "");
                File file = new File(id);
                if (file.exists())
                    return id;

            final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
            return getDataColumn(context, contentUri, null, null);
        // MediaProvider
        else if (isMediaDocument(uri)) {
            final String docId = DocumentsContract.getDocumentId(uri);
            final String[] split = docId.split(":");
            final String type = split[0];

            Uri contentUri = null;
            if ("image".equals(type)) {
                contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
            } else if ("video".equals(type)) {
                contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
            } else if ("audio".equals(type)) {
                contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;

            final String selection = "_id=?";
            final String[] selectionArgs = new String[]{

            return getDataColumn(context, contentUri, selection, selectionArgs);
    // MediaStore (and general)
    else if ("content".equalsIgnoreCase(uri.getScheme())) {

        // Return the remote address
        if (isGooglePhotosUri(uri))
            return uri.getLastPathSegment();

        return getDataColumn(context, uri, null, null);
    // File
    else if ("file".equalsIgnoreCase(uri.getScheme())) {
        return uri.getPath();

    return null;

For more solution click on the link here

I hope will do the same for you!

Send Post Request with params using Retrofit

The good way in my opinion is to send it in the POST Body this means you'll have a create a new POJO but some might like this implementation the most.

public interface APIInterface {
    List<LandingPageReport> getLandingPageReport(@Body Report report);

Then make your POJO with a constructor, getters and setters.

public static class Report {
    private String code;
    private String monthact;

    public Report(String code, String monthact) {
        this.code = code;
        this.monthact = monthact;  

    // Getters and Setters...

And just call it the normal way.

Call<List<Report>> request = apiInterface
    .getLandingPageReport(new Report(code, monthact));

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

IP Address

You can get network interfaces with NetworkInterface.getNetworkInterfaces(), then the IP addresses off the NetworkInterface objects returned with .getInetAddresses(), then the string representation of those addresses with .getHostAddress().


If you make a @Configuration class which implements ApplicationListener<EmbeddedServletContainerInitializedEvent>, you can override onApplicationEvent to get the port number once it's set.

public void onApplicationEvent(EmbeddedServletContainerInitializedEvent event) {
    int port = event.getEmbeddedServletContainer().getPort();

How to add an image to the emulator gallery in android studio?

It's a very old question but I will answer this for future references.

To add any file to emulator just drag and drop the file.

The file will be copied to downloads folder of internal storage.

To access the file

Go to settings

Click On Storage & USB

Click On Internal Storage

Click On Explore (at the end)

and you got it in the downloads folder

now you will get notification to setup virtual SD card, follow the setup. after the successful setup you will be able to see pictures in gallery.

changing kafka retention period during runtime

log.retention.hours is a property of a broker which is used as a default value when a topic is created. When you change configurations of currently running topic using, you should specify a topic-level property.

A topic-level property for log retention time is

From Topic-level configuration in Kafka 0.8.1 documentation:

  • Property:
  • Default: 7 days
  • Server Default Property: log.retention.minutes
  • Description: This configuration controls the maximum time we will retain a log before we will discard old log segments to free up space if we are using the "delete" retention policy. This represents an SLA on how soon consumers must read their data.

So the correct command depends on the version. Up to 0.8.2 (although docs still show its use up to 0.10.1) use --alter and after 0.10.2 (or perhaps from 0.9.0 going forward) use --alter

$ bin/ --zookeeper --alter --topic as-access --config

You can check whether the configuration is properly applied with the following command.

$ bin/ --describe --zookeeper --topic as-access

Then you will see something like below.

Topic:as-access  PartitionCount:3  ReplicationFactor:3

How to unlock android phone through ADB

Slightly modifying answer by @Yogeesh Seralathan. His answer works perfectly, just run these commands at once.

adb shell input keyevent 26 && adb shell input touchscreen swipe 930 880 930 380 && adb shell input text XXXX && adb shell input keyevent 66

Single selection in RecyclerView

Please try this... This works for me..

In adapter,take a sparse boolean array.

SparseBooleanArray sparseBooleanArray;

In constructor initialise this,

   sparseBooleanArray=new SparseBooleanArray();

In bind holder add,

public void onBindViewHolder(DispositionViewHolder holder, final int position) {


private void setClickListner(final DispositionViewHolder holder, final int position) {
    holder.rd_disp.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            sparseBooleanArray.put(position, true);


rd_disp is radio button in xml file.

So when the recycler view load the items,in bindView Holder it check whether the sparseBooleanArray contain the value "true" correspnding to its position.

If the value returned is true then we set the radio button selection true.Else we set the selection false. In onclickHolder I have cleared the sparseArray and set the value true corresponding to that position. When I call notify datasetChange it again call the onBindViewHolder and the condition are checked again. This makes our selection to only select particular radio.

java.lang.IllegalStateException: Fragment not attached to Activity

Sometimes this exception is caused by a bug in the support library implementation. Recently I had to downgrade from 26.1.0 to 25.4.0 to get rid of it.

Spring boot - Not a managed type

I have the same probblem, in version spring boot v1.3.x what i did is upgrade spring boot to version 1.5.7.RELEASE. Then the probblem gone.

Base64: java.lang.IllegalArgumentException: Illegal character

I encountered this error since my encoded image started with data:image/png;base64,iVBORw0....

This answer led me to the solution:

String partSeparator = ",";
if (data.contains(partSeparator)) {
  String encodedImg = data.split(partSeparator)[1];
  byte[] decodedImg = Base64.getDecoder().decode(encodedImg.getBytes(StandardCharsets.UTF_8));
  Path destinationFile = Paths.get("/path/to/imageDir", "myImage.jpg");
  Files.write(destinationFile, decodedImg);

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

@Service: It tells that particular class is a Service to the client. Service class contains mainly business Logic. If you have more Service classes in a package than provide @Qualifier otherwise it should not require @Qualifier.

Case 1:

public class EmployeeServiceImpl implements EmployeeService{


public class EmployeeServiceImpl implements EmployeeService{

both cases are working...

Google Chrome forcing download of "f.txt" file

This can occur on android too not just computers. Was browsing using Kiwi when the site I was on began to endlessly redirect so I cut net access to close it out and noticed my phone had DL'd something f.txt in my downloaded files.

Deleted it and didn't open.

"Expected BEGIN_OBJECT but was STRING at line 1 column 1"

I had a case where I read from a handwritten json file. The json is perfect. However, this error occurred. So I write from a java object to json file, then read from that json file. things are fine. I could not see any difference between the handwritten json and the one from java object. Tried beyondCompare it sees no difference. I finally noticed the two file sizes are slightly different, and I used winHex tool and detected extra stuff. So the solution for my situation is, make copy of the good json file, paste content into it and use.

enter image description here

Spring Could not Resolve placeholder

My solution was to add a space between the $ and the {.

For example:



@Value("$ {appclient.port:}")

Spring Maven clean error - The requested profile "pom.xml" could not be activated because it does not exist

The warning message

[WARNING] The requested profile "pom.xml" could not be activated because it does not exist.

means that you somehow passed -P pom.xml to Maven which means "there is a profile called pom.xml; find it and activate it". Check your environment and your settings.xml for this flag and also look at all <profile> elements inside the various XML files.

Usually, mvn help:effective-pom is also useful to see what the real POM would look like.

Now the error means that you tried to configure Maven to build Java 8 code but you're not using a Java 8 runtime. Solutions:

  1. Install Java 8
  2. Make sure Maven uses Java 8 if you have it installed. JAVA_HOME is your friend
  3. Configure the Java compiler in your pom.xml to a Java version which you actually have.


The specified child already has a parent. You must call removeView() on the child's parent first (Android)

You must first remove the child view from its parent.

If your project is in Kotlin, your solution will look slightly different than Java. Kotlin simplifies casting with as?, returning null if left side is null or cast fails.

(childView.parent as? ViewGroup)?.removeView(childView)

Kotlin Extension Solution

If you need to do this more than once, add this extension to make your code more readable.


fun View?.removeSelf() {
    this ?: return
    val parentView = parent as? ViewGroup ?: return

It will safely do nothing if this View is null, parent view is null, or parent view is not a ViewGroup

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

From the looks of things you haven't passed enough data to Spring Boot to configure the datasource

Create/In your existing add the following


making sure you append a value for each of properties.

File upload along with other object in Jersey restful web service

I used file upload example from,

in my resource class i have below method

    public Response  attachupload(@FormDataParam("file") byte[] is,
@FormDataParam("file") FormDataContentDisposition fileDetail,
@FormDataParam("fileName") String flename){

in my i have below method

 public void saveAttachment(String flename,  byte[] is) {
            // TODO Auto-generated method stub


in Dao i have


in my HBM mapping is like

<property name="data" type="binary" >
            <column name="data" />

This working for all type of files like .PDF,.TXT, .PNG etc.,

How to get the SHA-1 fingerprint certificate in Android Studio for debug mode?

  • Go to File > Project Structure Select app or mobile whatever you gave the name from Modules

  • Choose Signing tab.

  • You can add certificate clicking on the + button.

Debugging with Android Studio stuck at "Waiting For Debugger" forever

This solution works for me:

turning off the USB debugging from my device settings , and then turning it on again.

its Much quicker and easier than restart the device.

ORA-01653: unable to extend table by in tablespace ORA-06512

Just add a new datafile for the existing tablespace

ALTER TABLESPACE LEGAL_DATA ADD DATAFILE '/u01/oradata/userdata03.dbf' SIZE 200M;

To find out the location and size of your data files:


Why am I getting a " Traceback (most recent call last):" error?

At the beginning of your file you set raw_input to 0. Do not do this, at it modifies the built-in raw_input() function. Therefore, whenever you call raw_input(), it is essentially calling 0(), which raises the error. To remove the error, remove the first line of your code:

M = 1.6
# Miles to Kilometers 
# Celsius Celsius = (var1 - 32) * 5/9
# Gallons to liters Gallons = 3.6
# Pounds to kilograms Pounds = 0.45
# Inches to centimete Inches = 2.54

def intro():
    print("Welcome! This program will convert measures for you.")

def main():
    print("Select operation.")
    print("1.Miles to Kilometers")
    print("2.Fahrenheit to Celsius")
    print("3.Gallons to liters")
    print("4.Pounds to kilograms")
    print("5.Inches to centimeters")

    choice = input("Enter your choice by number: ")

    if choice == '1':

    elif choice == '2':

    elif choice == '3':

    elif choice == '4':

    elif choice == '5':


def convertMK():
    input_M = float(raw_input(("Miles: ")))
    M_conv = (M) * input_M
    print("Kilometers: %f\n" % M_conv)
    restart = str(input("Do you wish to make another conversion? [y]Yes or [n]no: "))
    if restart == 'y':
    elif restart == 'n':
        print("I didn't quite understand that answer. Terminating.")

def converCF():
    input_F = float(raw_input(("Fahrenheit: ")))
    F_conv = (input_F - 32) * 5/9
    print("Celcius: %f\n") % F_conv
    restart = str(input("Do you wish to make another conversion? [y]Yes or [n]no: "))
    if restart == 'y':
    elif restart == 'n':
        print("I didn't quite understand that answer. Terminating.")

def convertGL():
    input_G = float(raw_input(("Gallons: ")))
    G_conv = input_G * 3.6
    print("Centimeters: %f\n" % G_conv)
    restart = str(input("Do you wish to make another conversion? [y]Yes or [n]no: "))
    if restart == 'y':
    elif restart == 'n':
        print ("I didn't quite understand that answer. Terminating.")

def convertPK():
    input_P = float(raw_input(("Pounds: ")))
    P_conv = input_P * 0.45
    print("Centimeters: %f\n" % P_conv)
    restart = str(input("Do you wish to make another conversion? [y]Yes or [n]no: "))
    if restart == 'y':
    elif restart == 'n':
        print ("I didn't quite understand that answer. Terminating.")

def convertIC():
    input_cm = float(raw_input(("Inches: ")))
    inches_conv = input_cm * 2.54
    print("Centimeters: %f\n" % inches_conv)
    restart = str(input("Do you wish to make another conversion? [y]Yes or [n]no: "))
    if restart == 'y':
    elif restart == 'n':
        print ("I didn't quite understand that answer. Terminating.")

def end():
    print("This program will close.")


Tomcat 8 throwing - org.apache.catalina.webresources.Cache.getResource Unable to add the resource

You have more static resources that the cache has room for. You can do one of the following:

  • Increase the size of the cache
  • Decrease the TTL for the cache
  • Disable caching

For more details see the documentation for these configuration options.

Spring Boot yaml configuration for a list of strings

use comma separated values in application.yml

ignoreFilenames: .DS_Store, .hg

java code for access

String[] ignoreFilenames

It is working ;)

How do I get the position selected in a RecyclerView?

1. Create class Name

import android.content.Context;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;

public class RecyclerTouchListener implements RecyclerView.OnItemTouchListener 

private GestureDetector gestureDetector;
private ClickListener clickListener;

public RecyclerTouchListener(Context context, final RecyclerView recyclerView, final ClickListener clickListener) {
    this.clickListener = clickListener;
    gestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
        public boolean onSingleTapUp(MotionEvent e) {
            return true;

        public void onLongPress(MotionEvent e) {
            View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
            if (child != null && clickListener != null) {
                clickListener.onLongClick(child, recyclerView.getChildAdapterPosition(child));

public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {

    View child = rv.findChildViewUnder(e.getX(), e.getY());
    if (child != null && clickListener != null && gestureDetector.onTouchEvent(e)) {
        clickListener.onClick(child, rv.getChildAdapterPosition(child));
    return false;

public void onTouchEvent(RecyclerView rv, MotionEvent e) {

public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {


public interface ClickListener {
    void onClick(View view, int position);

    void onLongClick(View view, int position);

2. Call RecyclerTouchListener

recycleView.addOnItemTouchListener(new RecyclerTouchListener(this, recycleView, 
new RecyclerTouchListener.ClickListener() {
    public void onClick(View view, int position) {

    public void onLongClick(View view, int position) {


Android: making a fullscreen application

Add these to Activity of your application.

Android JAVA



Android Kotlin


This Activity already has an action bar supplied by the window decor

I had toolbar added in my xml. Then in my activity i was adding this statement:


Removing this worked for me. I hope it helps someone.

how to fix Cannot call sendRedirect() after the response has been committed?

you have already forwarded the response in catch block:

RequestDispatcher dd = request.getRequestDispatcher("error.jsp");

dd.forward(request, response);

so, you can not again call the :


because it is already forwarded (committed).

So what you can do is: keep a string to assign where you need to forward the response.

    String page = "";
    try {

    } catch (Exception e) {
      page = "error.jsp";
    } finally {
      page = "usertaskpage.jsp";

RequestDispatcher dd=request.getRequestDispatcher(page);
dd.forward(request, response);

How to solve ADB device unauthorized in Android ADB host device?

Check and uncheck the USB Debugging option in the device. If that doesn't work unplug and plug in the USB a couple of times.

At some point, the device should show a message box to ask you to authorize the computer. Click yes and then the device will be authorized.

Using tr to replace newline with space

Best guess is you are on windows and your line ending settings are set for windows. See this topic: How to change line-ending settings

or use:

tr '\r\n' ' '

How to allow user to pick the image with Swift?

XCODE 10.1 / SWIFT 4.2 :

  1. Add required permissions (others mentioned)

  2. Add this class to your view:

    import UIKit

    import Photos

    import Foundation

class UploadImageViewController: UIViewController, UIImagePickerControllerDelegate , UINavigationControllerDelegate {

        @IBOutlet weak var imgView: UIImageView!

        let imagePicker = UIImagePickerController()

        override func viewDidLoad() {



            imagePicker.delegate = self
            imagePicker.allowsEditing = false
            imagePicker.sourceType = .photoLibrary

        @IBAction func btnSetProfileImageClickedCamera(_ sender: UIButton) {

        @IBAction func btnSetProfileImageClickedFromGallery(_ sender: UIButton) {

        func selectPhotoFromGallery() {
            self.present(imagePicker, animated: true, completion: nil)

        func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {

            if let pickedImage = info[UIImagePickerController.InfoKey.originalImage] as? UIImage {
                    self.imgView.contentMode = .scaleAspectFit
                    self.imgView.image = pickedImage

            dismiss(animated: true, completion: nil)

        func imagePickerControllerDidCancel(_ picker: UIImagePickerController){
            print("cancel is clicked")

        func checkPermission() {
            let photoAuthorizationStatus = PHPhotoLibrary.authorizationStatus()
            switch photoAuthorizationStatus {
            case .authorized:
                print("Access is granted by user")
            case .notDetermined:
                    (newStatus) in
                    print("status is \(newStatus)")
                    if newStatus ==  PHAuthorizationStatus.authorized {
                        /* do stuff here */
                print("It is not determined until now")
            case .restricted:
                // same same
                print("User do not have access to photo album.")
            case .denied:
                // same same
                print("User has denied the permission.")

adb shell su works but adb root does not

I have a rooted Samsung Galaxy Trend Plus (GT-S7580).

Running 'adb root' gives me the same 'adbd cannot run as root in production builds' error.

For devices that have Developer Options -> Root access, choose "ADB only" to provide adb root access to the device (as suggested by NgaNguyenDuy).

Then try to run the command as per the solution at Launch a script as root through ADB. In my case, I just wanted to run the 'netcfg rndis0 dhcp' command, and I did it this way:

adb shell "su -c netcfg rndis0 dhcp"

Please check whether you are making any mistakes while running it this way.

If it still does not work, check whether you rooted the device correctly. If still no luck, try installing a custom ROM such as Cyanogen Mod in order for 'adb root' to work.

Spring Boot Remove Whitelabel Error Page

This depends on your spring boot version:

When SpringBootVersion <= 1.2 then use error.whitelabel.enabled = false

When SpringBootVersion >= 1.3 then use server.error.whitelabel.enabled = false

Android Studio doesn't recognize my device

LG Optimus Zone 2 pp415 d\n connect in mtp, but does work in internet connection mode. Lost lots of time messing with it. There's no doc for this, but I'd suggest trying all 4 of the connection options. Only 1 that works for me is Internet Connection->Ethernet, then win 8 auto-detects a driver and installs it. In MTP mode despite all drivers being registered with device manager, adb doesn't pick it up.

What is an AssertionError? In which case should I throw it from my own code?

Of course the "You shall not instantiate an item of this class" statement has been violated, but if this is the logic behind that, then we should all throw AssertionErrors everywhere, and that is obviously not what happens.

The code isn't saying the user shouldn't call the zero-args constructor. The assertion is there to say that as far as the programmer is aware, he/she has made it impossible to call the zero-args constructor (in this case by making it private and not calling it from within Example's code). And so if a call occurs, that assertion has been violated, and so AssertionError is appropriate.

Failed to load ApplicationContext from Unit Test: FileNotFound

The problem is insufficient memory to load context.

Try to set VM options:

-da -Xmx2048m -Xms1024m -XX:MaxPermSize=2048m

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

Here is a simple solution

try adding this dependency


Java Error: illegal start of expression

public static int [] locations={1,2,3};

public static test dot=new test();

Declare the above variables above the main method and the code compiles fine.

public static void main(String[] args){

python numpy ValueError: operands could not be broadcast together with shapes

Convert the arrays to matrices, and then perform the multiplication.

X = np.matrix(X)

y = np.matrix(y)


How to manually force a commit in a @Transactional method?

I know that due to this ugly anonymous inner class usage of TransactionTemplate doesn't look nice, but when for some reason we want to have a test method transactional IMHO it is the most flexible option.

In some cases (it depends on the application type) the best way to use transactions in Spring tests is a turned-off @Transactional on the test methods. Why? Because @Transactional may leads to many false-positive tests. You may look at this sample article to find out details. In such cases TransactionTemplate can be perfect for controlling transaction boundries when we want that control.

PowerShell The term is not recognized as cmdlet function script file or operable program

For the benefit of searchers, there is another way you can produce this error message - by missing the $ off the script block name when calling it.

e.g. I had a script block like so:

$qa = {
    param($question, $answer)
    Write-Host "Question = $question, Answer = $answer"

I tried calling it using:

&qa -question "Do you like powershell?" -answer "Yes!"

But that errored. The correct way was:

&$qa -question "Do you like powershell?" -answer "Yes!"

Deserialize JSON to Array or List with HTTPClient .ReadAsAsync using .NET 4.0 Task pattern

var response = taskwithresponse.Result;
          var jsonString = response.ReadAsAsync<List<Job>>().Result;

Retrofit and GET using parameters

@QueryMap worked for me instead of FieldMap

If you have a bunch of GET params, another way to pass them into your url is a HashMap.

class YourActivity extends Activity {

private static final String BASEPATH = "";

private interface API {
    void getMyThing(@QueryMap Map<String, String> params, new Callback<String> callback);

public void onCreate(Bundle savedInstanceState) {

   RestAdapter rest = new RestAdapter.Builder().setEndpoint(BASEPATH).build();
   API service = rest.create(API.class);

   Map<String, String> params = new HashMap<String, String>();
   params.put("key1", "val1");
   params.put("key2", "val2");
   // ... as much as you need.

   service.getMyThing(params, new Callback<String>() {
       // ... do some stuff here.

The URL called will be

Chrome's remote debugging (USB debugging) not working for Samsung Galaxy S3 running android 4.3

After looking around a little longer I came across this. Apparently, there isn't a solution to this issue yet, but there is a workaround - going back to the legacy workflow.

The legacy workflow did work for me, and the only additional thing I had to do was to go to the platform-tools folder from android SDK download, open a command window here and run command "adb devices". This caused the computer RSA key fingerprint panel to pop on my mobile screen, and after granting permission, the device showed up under Chrome's Inspect page.

Turns out that it was not an issue caused by mobile OS upgrade but by Chrome (I was thrown off by the fact that it worked on my Nexus4 somehow). In the older versions of Chrome there was't a need to download the 500 odd mb Android SDK, as it supported an ADB plugin. But with latest version of Chrome, I guess, going legacy is the only way to go.

What is the (best) way to manage permissions for Docker shared volumes?

This is arguably not the best way for most circumstances, but it's not been mentioned yet so perhaps it will help someone.

  1. Bind mount host volume

    Host folder FOOBAR is mounted in container /volume/FOOBAR

  2. Modify your container's startup script to find GID of the volume you're interested in

    $ TARGET_GID=$(stat -c "%g" /volume/FOOBAR)

  3. Ensure your user belongs to a group with this GID (you may have to create a new group). For this example I'll pretend my software runs as the nobody user when inside the container, so I want to ensure nobody belongs to a group with a group id equal to TARGET_GID

  EXISTS=$(cat /etc/group | grep $TARGET_GID | wc -l)

  # Create new group using target GID and add nobody user
  if [ $EXISTS == "0" ]; then
    groupadd -g $TARGET_GID tempgroup
    usermod -a -G tempgroup nobody
    # GID exists, find group name and add
    GROUP=$(getent group $TARGET_GID | cut -d: -f1)
    usermod -a -G $GROUP nobody

I like this because I can easily modify group permissions on my host volumes and know that those updated permissions apply inside the docker container. This happens without any permission or ownership modifications to my host folders/files, which makes me happy.

I don't like this because it assumes there's no danger in adding yourself to an arbitrary groups inside the container that happen to be using a GID you want. It cannot be used with a USER clause in a Dockerfile (unless that user has root privileges I suppose). Also, it screams hack job ;-)

If you want to be hardcore you can obviously extend this in many ways - e.g. search for all groups on any subfiles, multiple volumes, etc.

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?

When you really want to write an i-test for a spring data repository you can do it like this:

@EnableJpaRepositories(basePackageClasses = WebBookingRepository.class)
@EntityScan(basePackageClasses = WebBooking.class)
public class WebBookingRepositoryIntegrationTest {

    private WebBookingRepository repository;

    public void testSaveAndFindAll() {
        WebBooking webBooking = new WebBooking();
        webBooking.setUuid("some uuid");
        webBooking.setItems(Arrays.asList(new WebBookingItem()));;

        Iterable<WebBooking> findAll = repository.findAll();


To follow this example you have to use these dependencies:


ADB Android Device Unauthorized

Had similar issue on osx and Nexus 5 (A6.0.1). I did get the authorization pop-up and confirmed it, despite that Android Studio nor any other IDE could connect to device.

Turned out my Nexus (rooted) was missing key files.

  • Rebooted Android device into recovery
  • Ran code pasted below
  • Rebooted Android device, adb now identifies device

Push key from computer to Android device:

 cd ~/.android && adb push /data/misc/adb/adb_keys

Solution came from here

Open files in 'rt' and 'wt' modes

t refers to the text mode. There is no difference between r and rt or w and wt since text mode is the default.

Documented here:

Character   Meaning
'r'     open for reading (default)
'w'     open for writing, truncating the file first
'x'     open for exclusive creation, failing if the file already exists
'a'     open for writing, appending to the end of the file if it exists
'b'     binary mode
't'     text mode (default)
'+'     open a disk file for updating (reading and writing)
'U'     universal newlines mode (deprecated)

The default mode is 'r' (open for reading text, synonym of 'rt').

Bootstrap push div content to new line

If your your list is dynamically generated with unknown number and your target is to always have last div in a new line set last div class to "col-xl-12" and remove other classes so it will always take a full row.

This is a copy of your code corrected so that last div always occupy a full row (I although removed unnecessary classes).

<link href="" rel="stylesheet">_x000D_
<div class="grid">_x000D_
  <div class="row">_x000D_
    <div class="col-sm-3">Under me should be a DIV</div>_x000D_
    <div class="col-md-6 col-sm-5">Under me should be a DIV</div>_x000D_
    <div class="col-xl-12">I am the last DIV and I always take a full row for my self!!</div>_x000D_

View not attached to window manager crash

Override onConfigurationChanged and dismiss progress dialog. If progress dialog is created in portrait and dismisses in landscape then it will throw View not attached to window manager error.

Also stop the progress bar and stop the async task in onPause(), onBackPressed and onDestroy method.

if(asyncTaskObj !=null && asyncTaskObj.getStatus().equals(AsyncTask.Status.RUNNING)){



Couldn't load memtrack module Logcat Error

This error, as you can read on the question linked in comments above, results to be:

"[...] a problem with loading {some} hardware module. This could be something to do with GPU support, sdcard handling, basically anything."

The step 1 below should resolve this problem. Also as I can see, you have some strange package names inside your manifest:

  • package="com.example.hive" in <manifest> tag,
  • android:name="" for <application>
  • and android:name="com.sit.gems.activity" in <activity>

As you know, these things do not prevent your app to be displayed. But I think:

the Couldn't load memtrack module error could occur because of emulators configurations problems and, because your project contains many organization problems, it might help to give a fresh redesign.

For better using and with few things, this can be resolved by following these tips:

1. Try an other emulator...

And even a real device! The memtrack module error seems related to your emulator. So change it into Run configuration, don't forget to change the API too.

2. OpenGL error logs

For OpenGl errors, as called unimplemented OpenGL ES API, it's not an error but a statement! You should enable it in your manifest (you can read this answer if you're using GLSurfaceView inside, it might help you):

<uses-feature android:glEsVersion="0x00020000"></uses-feature>  
// or
<uses-feature android:glEsVersion="0x00010001" android:required="true" />

3. Use the same package

Don't declare different package names to all the tags in Manifest. You should have the same for Manifest, Activities, etc. Something like this looks right:

<!-- set the general package -->
<manifest xmlns:android=""
    android:versionName="1.0" >

    <!-- don't set a package name in <application> -->
    <application ... >

        <!-- then, declare the activities -->
            android:name="com.sit.gems.activity.SplashActivity" ... >
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
        <!-- same package here -->
            android:name="com.sit.gems.activity.HomeActivity" ... >

4. Don't get lost with layouts:

You should set another layout for because you're not using the TabHost for the splash screen and this is not a safe resource way. Declare a specific layout with something different, like the app name and the logo:

// inside SplashScreen class

// layout splash_screen.xml
<TextView xmlns:android=""
     android:text="@string/appname" />  

Avoid using a layout in activities which don't use it.

5. Splash Screen?

Finally, I don't understand clearly the purpose of your SplashScreenActivity. It sets a content view and directly finish. This is useless.

As its name is Splash Screen, I assume that you want to display a screen before launching your HomeActivity. Therefore, you should do this and don't use the TabHost layout ;):

// FragmentActivity is also useless here! You don't use a Fragment into it, so, use traditional Activity
public class SplashActivity extends Activity {
    protected void onCreate(Bundle savedInstanceState) {
        // set your splash_screen layout

        // create a new Thread
        new Thread(new Runnable() {
            public void run() {
                try {
                    // sleep during 800ms
                } catch (InterruptedException e) {
                // start HomeActivity
                startActivity(new Intent(SplashActivity.this, HomeActivity.class));

I hope this kind of tips help you to achieve what you want.
If it's not the case, let me know how can I help you.

illegal use of break statement; javascript

I have a function next() which will maybe inspire you.

function queue(target) {
        var array = Array.prototype;

        var queueing = [];

        target.queue = queue;
        target.queued = queued;

        return target;

        function queued(action) {
            return function () {
                var self = this;
                var args = arguments;

                queue(function (next) {
                    action.apply(self, array.concat.apply(next, args));

        function queue(action) {
            if (!action) {


            if (queueing.length === 1) {

        function next() {
            queueing[0](function (err) {
                if (err) {
                    throw err;

                queueing = queueing.slice(1);

                if (queueing.length) {

Cross-Origin Request Blocked

You need other headers, not only access-control-allow-origin. If your request have the "Access-Control-Allow-Origin" header, you must copy it into the response headers, If doesn't, you must check the "Origin" header and copy it into the response. If your request doesn't have Access-Control-Allow-Origin not Origin headers, you must return "*".

You can read the complete explanation here:

and this is the function I'm using to write cross domain headers:

func writeCrossDomainHeaders(w http.ResponseWriter, req *http.Request) {
    // Cross domain headers
    if acrh, ok := req.Header["Access-Control-Request-Headers"]; ok {
        w.Header().Set("Access-Control-Allow-Headers", acrh[0])
    w.Header().Set("Access-Control-Allow-Credentials", "True")
    if acao, ok := req.Header["Access-Control-Allow-Origin"]; ok {
        w.Header().Set("Access-Control-Allow-Origin", acao[0])
    } else {
        if _, oko := req.Header["Origin"]; oko {
            w.Header().Set("Access-Control-Allow-Origin", req.Header["Origin"][0])
        } else {
            w.Header().Set("Access-Control-Allow-Origin", "*")
    w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE")
    w.Header().Set("Connection", "Close")


How to fix Warning Illegal string offset in PHP

Please check that your key exists in the array or not, instead of simply trying to access it.


$myVar = $someArray['someKey']

With something like:

if (isset($someArray['someKey'])) {
    $myVar = $someArray['someKey']

or something like:

if(is_array($someArray['someKey'])) {
    $theme_img = 'recent_works_iso_thumbnail';
}else {
    $theme_img = 'recent_works_iso_thumbnail';
} no protocol on URL based on a string modified with URLEncoder

This code worked for me

public static void main(String[] args) {
    try { myUr = new"http://path");
        System.out.println("Instantiated new URL: " + connection_url);
    catch (MalformedURLException e) {

Instantiated new URL: http://path

Chrome DevTools Devices does not detect device when plugged in

Just adding this here for reference, I was trying to connect an LG G5 Android phone and Chrome dev tools did not recognize it until I downloaded the LG usb driver here.

Good luck, all!

You need to use a Theme.AppCompat theme (or descendant) with this activity

In Android Studio: Add support library to the gradle file and sync. Edit build.gradle(Module:app) to have dependencies as follows:

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    implementation ''
    implementation ''
    implementation ''

My support Library version is 23.1.1; use your support library version as applicable.

Uri content://media/external/file doesn't exist for some devices

Most probably it has to do with caching on the device. Catching the exception and ignoring is not nice but my problem was fixed and it seems to work.

ORA-01036: illegal variable name/number when running query through C#

I have faced same problem ... For the problem is like this, I am calling the PRC inside cpp program and my PRC taking 4 arguments but while calling I used only 1 arguments so this error came for me.

Begin Example_PRC(:1); End; // this cause the problem 
Begin Example_PRC(:1,:2,:3,:4); End; // this is the solution

Android ListView with onClick items

You start new activities with intents. One method to send data to an intent is to pass a class that implements parcelable in the intent. Take note you are passing a copy of the class.

Here I have an onItemClick. I create intent and putExtra an entire class into the intent. The class I'm sending has implemented parcelable. Tip: You only need implement the parseable over what is minimally needed to re-create the class. Ie maybe a filename or something simple like a string something that a constructor can use to create the class. The new activity can later getExtras and it is essentially creating a copy of the class with its constructor method.

Here I launch the kmlreader class of my app when I recieve an onclick in the listview.

Note: below summary is a list of the class that I am passing so get(position) returns the class infact it is the same list that populates the listview

List<KmlSummary> summary = null;

public final static String EXTRA_KMLSUMMARY = "com.gosylvester.bestrides.util.KmlSummary";


public void onItemClick(AdapterView<?> parent, View view, int position,
        long id) {
    lastshownitem = position;
    Intent intent = new Intent(context, KmlReader.class);

later in the new activity I pull out the parseable class with

kmlSummary = intent.getExtras().getParcelable(

//KmlSummary implements parcelable.
//there is a constructor method for parcel in
// and a overridden writetoparcel method
// these are really easy to setup.

public KmlSummary(Parcel in) {
    this._id = in.readInt();
    this._description = in.readString();
    this._name = in.readString();
    this.set_bounds(in.readDouble(), in.readDouble(), in.readDouble(),
    this._resrawid = in.readInt();
    this._resdrawableid = in.readInt();
     this._pathstring = in.readString();
    String s = in.readString();

public void writeToParcel(Parcel arg0, int arg1) {
    String s = Boolean.toString(this.isThumbCreated());

Good Luck Danny117

Scope 'session' is not active for the current thread; IllegalStateException: No thread-bound request found

You just need to define in your bean where you need a different scope than default singleton scope except prototype. For example:

<bean id="shoppingCart" 
   class="com.xxxxx.xxxx.ShoppingCartBean" scope="session">

Android Fragment onClick button Method

This is not an issue, this is a design of Android. See here:

You should design each fragment as a modular and reusable activity component. That is, because each fragment defines its own layout and its own behavior with its own lifecycle callbacks, you can include one fragment in multiple activities, so you should design for reuse and avoid directly manipulating one fragment from another fragment.

A possible workaround would be to do something like this in your MainActivity:

Fragment someFragment;    

...onCreate etc instantiating your fragments

public void myClickMethod(View v){

and then in your Fragment class:

public void myClickMethod(View v){
       // Your code here

SEVERE: ContainerBase.addChild: start:org.apache.catalina.LifecycleException: Failed to start error

Weird error, you can try methods given by james goooseling and also I have done it by following ways:

  • Remove all jars or libraries from build path and lib folders and add them again in lib folder or build path as you wish.

  • Check if you have servlet annotation @WebServlet for given servlet and if it has mapping in web.xml as well .. this is most common error due to which tomcat gets confused , that what url pattern must he use.

Is it possible to write data to file using only JavaScript?

Above answer is useful but, I found code which helps you to download text file directly on button click. In this code you can also change filename as you wish. It's pure javascript function with HTML5. Works for me!

function saveTextAsFile()
    var textToWrite = document.getElementById("inputTextToSave").value;
    var textFileAsBlob = new Blob([textToWrite], {type:'text/plain'});
    var fileNameToSaveAs = document.getElementById("inputFileNameToSaveAs").value;
      var downloadLink = document.createElement("a"); = fileNameToSaveAs;
    downloadLink.innerHTML = "Download File";
    if (window.webkitURL != null)
        // Chrome allows the link to be clicked
        // without actually adding it to the DOM.
        downloadLink.href = window.webkitURL.createObjectURL(textFileAsBlob);
        // Firefox requires the link to be added to the DOM
        // before it can be clicked.
        downloadLink.href = window.URL.createObjectURL(textFileAsBlob);
        downloadLink.onclick = destroyClickedElement; = "none";

Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2

Response you are getting is in object form i.e.

  "dstOffset" : 3600, 
  "rawOffset" : 36000, 
  "status" : "OK", 
  "timeZoneId" : "Australia/Hobart", 
  "timeZoneName" : "Australian Eastern Daylight Time" 

Replace below line of code :

List<Post> postsList = Arrays.asList(gson.fromJson(reader,Post.class))


Post post = gson.fromJson(reader, Post.class);

Launching Spring application Address already in use

You can resolve this following these steps:

  1. Right click on the project you are running.
  2. Click on Run as and Run Configurations from the option.
  3. A new run configuration will open. Under Spring Boot Tab see for Override properties.
  4. Add the property-value pair as server.port=8181, or any other port of your choice. This will override the default port which is 8080

Bootstrap 3 navbar active li not changing background-color

Well, I had a similar challenge. Using the inspect element tool in Firefox, I was able to trace the markup and the CSS used to style the link when clicked. On click, the list item (li) is given a class of .open and it's the anchor tag in the class that is formatted with the grey color background.

To fix this, just add this to your stylesheet.

.nav .open > a
    // Put in styling

JS Client-Side Exif Orientation: Rotate and Mirror JPEG Images

The github project JavaScript-Load-Image provides a complete solution to the EXIF orientation problem, correctly rotating/mirroring images for all 8 exif orientations. See the online demo of javascript exif orientation

The image is drawn onto an HTML5 canvas. Its correct rendering is implemented in js/load-image-orientation.js through canvas operations.

Hope this saves somebody else some time, and teaches the search engines about this open source gem :)

Reading a resource file from within jar

In my case I finally made it with

import java.lang.Thread;

final BufferedReader in = new BufferedReader(new InputStreamReader(
); // no initial slash in file.txt

adb doesn't show nexus 5 device

This simple steps worked for me, I debug on my Nexus 5 and 5X devices on Windows 8.1.

The steps to follow are these:

1) Enable from Developers Options the Debug USB Mode

2) Unplug the device from the computer

3.1) Go to Settings ? Storage, in the ActionBar, click the option menu and choose USB computer connection.

3.2) If you didn't find the 3.1) option then go to Settings ? Developers Options ? Select USB Configuration.

4) Select Camera (PTP) connection.

5) Plug the device and you should have a popup on the device allowing you to accept the computer's incoming connection, or something like that.

6) If it doesn't work try to toggle the Debug USB Mode in the Developers Options Finally, you should see it now in the DDMS and voilà.

@Autowired - No qualifying bean of type found for dependency

Can you try annotating only your concrete implementation with @Component? Maybe the following answer could help. It is kind of a similar problem. I usually put Spring annotations in the implementation classes.

Could not resolve placeholder in string value

I had the same problem, resolved it by adding


in pom.xml :

before (didn't work):


after(it worked):


After that you just run mvn clean install and deploy application.

What is IllegalStateException?

Illegal State Exception is an Unchecked exception.

It indicate that method has been invoked at wrong time.


Thread t = new Thread();


Runtime Excpetion: IllegalThreadStateException

We cant start the Thread again, it will throw IllegalStateException.

Clear and refresh jQuery Chosen dropdown list

If trigger("chosen:updated"); not working, use .trigger("liszt:updated"); of @Nhan Tran it is working fine.

BeanFactory not initialized or already closed - call 'refresh' before

In the spring framework inside the springframework initialization Repository or controller annotation, the same class name can only exist a default instance, you can set the value name

Get real path from URI, Android KitKat new storage access framework

This answer is based on your somewhat vague description. I assume that you fired an intent with action: Intent.ACTION_GET_CONTENT

And now you get content:// back instead of the previously media provider URI, correct?

On Android 4.4 (KitKat) the new DocumentsActivity gets opened when an Intent.ACTION_GET_CONTENT is fired thus leading to grid view (or list view) where you can pick an image, this will return the following URIs to calling context (example): content:// (these are the URIs to the new document provider, it abstracts away the underlying data by providing generic document provider URIs to clients).

You can however access both gallery and other activities responding to Intent.ACTION_GET_CONTENT by using the drawer in the DocumentsActivity (drag from left to right and you'll see a drawer UI with Gallery to choose from). Just as pre KitKat.

If you still which to pick in DocumentsActivity class and need the file URI, you should be able to do the following (warning this is hacky!) query (with contentresolver):content:// URI and read the _display_name value from the cursor. This is somewhat unique name (just the filename on local files) and use that in a selection (when querying) to mediaprovider to get the correct row corresponding to this selection from here you can fetch the file URI as well.

The recommended ways of accessing document provider can be found here (get an inputstream or file descriptor to read file/bitmap):

Examples of using documentprovider

Android Gallery on Android 4.4 (KitKat) returns different URI for Intent.ACTION_GET_CONTENT

Please try to avoid using takePersistableUriPermission method because it raised runtime exception for me. /** * Select from gallery. */

public void selectFromGallery() {
    if (Build.VERSION.SDK_INT < AppConstants.KITKAT_API_VERSION) {

        Intent intent = new Intent(); 

    } else {

        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        ((Activity)mCalledContext).startActivityForResult(intent, AppConstants.GALLERY_AFTER_KITKAT_INTENT_CALLED);

OnActivity for result to handle the image data:

@Override protected void onActivityResult(int requestCode, int resultCode, Intent data) {

    //gallery intent result handling before kit-kat version
            && resultCode == RESULT_OK) {

        Uri selectedImage = data.getData();
        String[] filePathColumn = {MediaStore.Images.Media.DATA};
        Cursor cursor = getContentResolver().query(selectedImage,filePathColumn, null, null, null);
        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        String filePath = cursor.getString(columnIndex);
        photoFile = new File(filePath);

    //gallery intent result handling after kit-kat version
    else if (requestCode == AppConstants.GALLERY_AFTER_KITKAT_INTENT_CALLED 
            && resultCode == RESULT_OK) {

        Uri selectedImage = data.getData();
        InputStream input = null;
        OutputStream output = null;

        try {
            //converting the input stream into file to crop the 
            //selected image from sd-card.
            input = getApplicationContext().getContentResolver().openInputStream(selectedImage);
            try {
                photoFile = mImgCropping.createImageFile();
            } catch (IOException e) {
            }catch(Exception e) {
            output = new FileOutputStream(photoFile);

            int read = 0;
            byte[] bytes = new byte[1024];

            while ((read = != -1) {
                try {
                    output.write(bytes, 0, read);
                } catch (IOException e) {
        } catch (FileNotFoundException e) {
        } catch (IOException e) {
        } catch (Exception e) {


How to append a jQuery variable value inside the .html tag

See this Link


<div id="products"></div>


var someone = {
"name":"Mahmoude Elghandour",
"price":"174 SR",
"desc":"WE Will BE WITH YOU"
 var name = $("<div/>",{"text","class":"name"

var price = $("<div/>",{"text":someone.price,"class":"price"});
var desc = $("<div />", {   
"text": someone.desc,
"class": "desc"

How to select option in drop down protractorjs e2e tests

To access a specific option you need to provide the nth-child() selector:

ptor.findElement(protractor.By.css('select option:nth-child(1)')).click();

Select multiple images from android gallery

For selecting multiple image from gallery


An Ultimate Solution for multiple image upload with camera option also for Android Lollipop to Android 10, SDK 30.

private static final int FILECHOOSER_RESULTCODE   = 1;
private ValueCallback<Uri> mUploadMessage;
private ValueCallback<Uri[]> mUploadMessages;
private Uri mCapturedImageURI = null;

Add this to OnCreate of MainActivity

mWebView.setWebChromeClient(new WebChromeClient() {

            // openFileChooser for Android 3.0+

            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType){
                mUploadMessage = uploadMsg;

            // For Lollipop 5.0+ Devices

            public boolean onShowFileChooser(WebView mWebView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams) {
                mUploadMessages = filePathCallback;
                return true;

            // openFileChooser for Android < 3.0

            public void openFileChooser(ValueCallback<Uri> uploadMsg){
                openFileChooser(uploadMsg, "");

            //openFileChooser for other Android versions

            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
                openFileChooser(uploadMsg, acceptType);

private void openImageChooser() {
    try {
        File imageStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES), "FolderName");
        if (!imageStorageDir.exists()) {
        File file = new File(imageStorageDir + File.separator + "IMG_" + String.valueOf(System.currentTimeMillis()) + ".jpg");
        mCapturedImageURI = Uri.fromFile(file);

        final Intent captureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        captureIntent.putExtra(MediaStore.EXTRA_OUTPUT, mCapturedImageURI);

        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        Intent chooserIntent = Intent.createChooser(i, "Image Chooser");
        chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, new Parcelable[]{captureIntent});

        startActivityForResult(chooserIntent, FILECHOOSER_RESULTCODE);
    } catch (Exception e) {



public void onActivityResult(final int requestCode, final int resultCode, final Intent data) {

        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == FILECHOOSER_RESULTCODE) {

            if (null == mUploadMessage && null == mUploadMessages) {

            if (null != mUploadMessage) {
                handleUploadMessage(requestCode, resultCode, data);

            } else if (mUploadMessages != null) {
                handleUploadMessages(requestCode, resultCode, data);


    private void handleUploadMessage(final int requestCode, final int resultCode, final Intent data) {
        Uri result = null;
        try {
            if (resultCode != RESULT_OK) {
                result = null;
            } else {
                // retrieve from the private variable if the intent is null

                result = data == null ? mCapturedImageURI : data.getData();
        } catch (Exception e) {
        mUploadMessage = null;

        // code for all versions except of Lollipop

                result = null;

                try {
                    if (resultCode != RESULT_OK) {
                        result = null;
                    } else {
                        // retrieve from the private variable if the intent is null
                        result = data == null ? mCapturedImageURI : data.getData();
                } catch (Exception e) {
                    Toast.makeText(getApplicationContext(), "activity :" + e, Toast.LENGTH_LONG).show();

                mUploadMessage = null;

        } // end of code for all versions except of Lollipop

    private void handleUploadMessages(final int requestCode, final int resultCode, final Intent data) {
        Uri[] results = null;
        try {
            if (resultCode != RESULT_OK) {
                results = null;
            } else {
                if (data != null) {
                    String dataString = data.getDataString();
                    ClipData clipData = data.getClipData();
                    if (clipData != null) {
                        results = new Uri[clipData.getItemCount()];
                        for (int i = 0; i < clipData.getItemCount(); i++) {
                            ClipData.Item item = clipData.getItemAt(i);
                            results[i] = item.getUri();
                    if (dataString != null) {
                        results = new Uri[]{Uri.parse(dataString)};
                } else {
                    results = new Uri[]{mCapturedImageURI};
        } catch (Exception e) {
        mUploadMessages = null;

Android: how to hide ActionBar on certain activities

For selectively hiding Actionbar in activities:

Add the following code to onCreate (preferably on the last line of the function)





Open a selected file (image, pdf, ...) programmatically from my Android Application?

You can get any file mime type with getContentResolver().getType(uri):

protected static void openFile(Context context, Uri localUri){
        Intent i = new Intent(Intent.ACTION_VIEW);
        i.setDataAndType(localUri, context.getContentResolver().getType(localUri));

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

You're mapping this JSON

    "id": 2,
    "socket": "0c317829-69bf-43d6-b598-7c0c550635bb",
    "type": "getDashboard",
    "data": {
        "workstationUuid": "ddec1caa-a97f-4922-833f-632da07ffc11"
    "reply": true

that contains an element named data that has a JSON object as its value. You are trying to deserialize the element named workstationUuid from that JSON object into this setter.

public void setWorkstation(String workstationUUID) {

This won't work directly because Jackson sees a JSON_OBJECT, not a String.

Try creating a class Data

public class Data { // the name doesn't matter 
    private String workstationUuid;
    // getter and setter

the switch up your method

public void setWorkstation(Data data) {
    // use getter to retrieve it

HTTP Status 500 - org.apache.jasper.JasperException: java.lang.NullPointerException

In Tomcat a .java and .class file will be created for every jsp files with in the application and the same can be found from the path below, Apache-Tomcat\work\Catalina\localhost\'ApplicationName'\org\apache\jsp\

In your case the jsp name is error.jsp so the path should be something like below Apache-Tomcat\work\Catalina\localhost\'ApplicationName'\org\apache\jsp\ in line no 124 you are trying to access a null object which results in null pointer exception.

RE error: illegal byte sequence on Mac OS X

A sample command that exhibits the symptom: sed 's/./@/' <<<$'\xfc' fails, because byte 0xfc is not a valid UTF-8 char.
Note that, by contrast, GNU sed (Linux, but also installable on macOS) simply passes the invalid byte through, without reporting an error.

Using the formerly accepted answer is an option if you don't mind losing support for your true locale (if you're on a US system and you never need to deal with foreign characters, that may be fine.)

However, the same effect can be had ad-hoc for a single command only:

LC_ALL=C sed -i "" 's|"iphoneos-cross","llvm-gcc:-O3|"iphoneos-cross","clang:-Os|g' Configure

Note: What matters is an effective LC_CTYPE setting of C, so LC_CTYPE=C sed ... would normally also work, but if LC_ALL happens to be set (to something other than C), it will override individual LC_*-category variables such as LC_CTYPE. Thus, the most robust approach is to set LC_ALL.

However, (effectively) setting LC_CTYPE to C treats strings as if each byte were its own character (no interpretation based on encoding rules is performed), with no regard for the - multibyte-on-demand - UTF-8 encoding that OS X employs by default, where foreign characters have multibyte encodings.

In a nutshell: setting LC_CTYPE to C causes the shell and utilities to only recognize basic English letters as letters (the ones in the 7-bit ASCII range), so that foreign chars. will not be treated as letters, causing, for instance, upper-/lowercase conversions to fail.

Again, this may be fine if you needn't match multibyte-encoded characters such as é, and simply want to pass such characters through.

If this is insufficient and/or you want to understand the cause of the original error (including determining what input bytes caused the problem) and perform encoding conversions on demand, read on below.

The problem is that the input file's encoding does not match the shell's.
More specifically, the input file contains characters encoded in a way that is not valid in UTF-8 (as @Klas Lindbäck stated in a comment) - that's what the sed error message is trying to say by invalid byte sequence.

Most likely, your input file uses a single-byte 8-bit encoding such as ISO-8859-1, frequently used to encode "Western European" languages.


The accented letter à has Unicode codepoint 0xE0 (224) - the same as in ISO-8859-1. However, due to the nature of UTF-8 encoding, this single codepoint is represented as 2 bytes - 0xC3 0xA0, whereas trying to pass the single byte 0xE0 is invalid under UTF-8.

Here's a demonstration of the problem using the string voilà encoded as ISO-8859-1, with the à represented as one byte (via an ANSI-C-quoted bash string ($'...') that uses \x{e0} to create the byte):

Note that the sed command is effectively a no-op that simply passes the input through, but we need it to provoke the error:

  # -> 'illegal byte sequence': byte 0xE0 is not a valid char.
sed 's/.*/&/' <<<$'voil\x{e0}'

To simply ignore the problem, the above LCTYPE=C approach can be used:

  # No error, bytes are passed through ('á' will render as '?', though).
LC_CTYPE=C sed 's/.*/&/' <<<$'voil\x{e0}'

If you want to determine which parts of the input cause the problem, try the following:

  # Convert bytes in the 8-bit range (high bit set) to hex. representation.
  # -> 'voil\x{e0}'
iconv -f ASCII --byte-subst='\x{%02x}' <<<$'voil\x{e0}'

The output will show you all bytes that have the high bit set (bytes that exceed the 7-bit ASCII range) in hexadecimal form. (Note, however, that that also includes correctly encoded UTF-8 multibyte sequences - a more sophisticated approach would be needed to specifically identify invalid-in-UTF-8 bytes.)

Performing encoding conversions on demand:

Standard utility iconv can be used to convert to (-t) and/or from (-f) encodings; iconv -l lists all supported ones.


Convert FROM ISO-8859-1 to the encoding in effect in the shell (based on LC_CTYPE, which is UTF-8-based by default), building on the above example:

  # Converts to UTF-8; output renders correctly as 'voilà'
sed 's/.*/&/' <<<"$(iconv -f ISO-8859-1 <<<$'voil\x{e0}')"

Note that this conversion allows you to properly match foreign characters:

  # Correctly matches 'à' and replaces it with 'ü': -> 'voilü'
sed 's/à/ü/' <<<"$(iconv -f ISO-8859-1 <<<$'voil\x{e0}')"

To convert the input BACK to ISO-8859-1 after processing, simply pipe the result to another iconv command:

sed 's/à/ü/' <<<"$(iconv -f ISO-8859-1 <<<$'voil\x{e0}')" | iconv -t ISO-8859-1

Bootstrap 3.0 Sliding Menu from left

Probably late but here is a plugin that can do the job :

Also v2 can use mobile gesture such as swipe ;)

How do I toggle an element's class in pure JavaScript?

don't need regex just use classlist

var id=document.getElementById('myButton');

function toggle(el,classname){




<button id="myButton">Switch</button>

Simple Usage above Example

var id=document.getElementById('myButton');

function toggle(el,classname){




<button id="myButton">Switch</button>

JavaScript array to CSV

for a simple csv one map() and a join() are enough:

var csv ={
    return d.join();

/* Results in 

This method also allows you to specify column separator other than a comma in the inner join. for example a tab: d.join('\t')

On the other hand if you want to do it properly and enclose strings in quotes "", then you can use some JSON magic:

var csv ={
   return JSON.stringify(d);
.replace(/(^\[)|(\]$)/mg, ''); // remove opening [ and closing ] brackets from each line 

/* would produce

if you have array of objects like :

var data = [
  {"title": "Book title 1", "author": "Name1 Surname1"},
  {"title": "Book title 2", "author": "Name2 Surname2"},
  {"title": "Book title 3", "author": "Name3 Surname3"},
  {"title": "Book title 4", "author": "Name4 Surname4"}

// use
var csv ={
    return JSON.stringify(Object.values(d));
.replace(/(^\[)|(\]$)/mg, '');

Check if list contains element that contains a string and get that element

The basic answer is: you need to iterate through loop and check any element contains the specified string. So, let's say the code is:

foreach(string item in myList)
       return item;

The equivalent, but terse, code is:

mylist.Where(x => x.Contains(myString)).FirstOrDefault();

Here, x is a parameter that acts like "item" in the above code.

IOException: read failed, socket might closed - Bluetooth on Android 4.3

First, if you need to talk to a bluetooth 2.x device, this documentation states that :

Hint: If you are connecting to a Bluetooth serial board then try using the well-known SPP UUID 00001101-0000-1000-8000-00805F9B34FB. However if you are connecting to an Android peer then please generate your own unique UUID.

I didn't think that it would work, but only by replacing the UUID with 00001101-0000-1000-8000-00805F9B34FB it works. However, this code seems to handle the problem of SDK version, and you can just replace the function device.createRfcommSocketToServiceRecord(mMyUuid); with tmp = createBluetoothSocket(mmDevice); after defining the following method :

private BluetoothSocket createBluetoothSocket(BluetoothDevice device)
    throws IOException {
    if(Build.VERSION.SDK_INT >= 10){
        try {
            final Method m = device.getClass().getMethod("createInsecureRfcommSocketToServiceRecord", new Class[] { UUID.class });
            return (BluetoothSocket) m.invoke(device, mMyUuid);
        } catch (Exception e) {
            Log.e(TAG, "Could not create Insecure RFComm Connection",e);
    return  device.createRfcommSocketToServiceRecord(mMyUuid);

The source code isn't mine, but comes from this website.

How to implement HorizontalScrollView like Gallery?

Here is a good tutorial with code. Let me know if it works for you! This is also a good tutorial.


In This example, all you need to do is add this line:


after setting the adapter to gallery object, that is this line:

gallery.setAdapter(new ImageAdapter(this));


Alright, I got your problem. This open source library is your solution. I also have used it for one of my projects. Hope this will solve your problem finally.


I would suggest you to go through this tutorial. You might get idea. I think I got your problem, you want the horizontal scrollview with snap. Try to search with that keyword on google or out here, you might get your solution.

Using setDate in PreparedStatement

Not sure, but what I think you're looking for is to create a java.util.Date from a String, then convert that java.util.Date to a java.sql.Date.

try this:

private static java.sql.Date getCurrentDate(String date) {

    java.util.Date today;
    java.sql.Date rv = null;
    try {

        SimpleDateFormat format = new SimpleDateFormat("dd-MM-yyyy");
        today = format.parse(date);
        rv = new java.sql.Date(today.getTime());

    } catch (Exception e) {
        System.out.println("Exception: " + e.getMessage());
    } finally {
        return rv;


Will return a java.sql.Date object for setDate();

The function above will print out a long value:


Check number of arguments passed to a Bash script

A simple one liner that works can be done using:

[ "$#" -ne 1 ] && ( usage && exit 1 ) || main

This breaks down to:

  1. test the bash variable for size of parameters $# not equals 1 (our number of sub commands)
  2. if true then call usage() function and exit with status 1
  3. else call main() function

Things to note:

  • usage() can just be simple echo "$0: params"
  • main can be one long script

Pass variable to function in jquery AJAX success callback

Just to share a similar problem I had in case it might help some one, I was using:

var NextSlidePage = $("bottomcontent" + Slide + ".html");

to make the variable for the load function, But I should have used:

var NextSlidePage = "bottomcontent" + Slide + ".html";

without the $( )

Don't know why but now it works! Thanks, finally i saw what was going wrong from this post!

Adding Table rows Dynamically in Android

You also can, as Fredigato said, declare a RelativeLayout in a separate Layout file. Then instantiate it using:

for(int i = 0; i < 6; i ++){
LayoutInflater inflater = (LayoutInflater)getApplicationContext().getSystemService
RelativeLayout row = (RelativeLayout) inflater.inflate(R.layout.table_view,null);

In this approach you can easily design one custom row using XML and reuse it.

Now, to be able to change the children views in the instantiated RelativeLayout. You can call row.childAt(index).

So lets say you have a TextView in the RelativeLayout, you can use:

TextView tv = (TextView) row.childAt(0);

ActionBarCompat: java.lang.IllegalStateException: You need to use a Theme.AppCompat

To simply add ActionBar Compat your activity or application should use @style/Theme.AppCompat theme in AndroidManifest.xml like this:

        android:theme="@style/Theme.AppCompat" />

This will add actionbar in activty(or all activities if you added this theme to application)

But usually you need to customize you actionbar. To do this you need to create two styles with Theme.AppCompat parent, for example, "@style/Theme.AppCompat.Light". First one will be for api 11>= (versions of android with build in android actionbar), second one for api 7-10 (no build in actionbar).

Let's look at first style. It will be located in res/values-v11/styles.xml . It will look like this:

<style name="Theme.Styled" parent="@style/Theme.AppCompat.Light">
    <!-- Setting values in the android namespace affects API levels 11+ -->
    <item name="android:actionBarStyle">@style/Widget.Styled.ActionBar</item>

<style name="Widget.Styled.ActionBar" parent="@style/Widget.AppCompat.Light.ActionBar">
    <!-- Setting values in the android namespace affects API levels 11+ -->
    <item name="android:background">@drawable/ab_custom_solid_styled</item>
    <item name="android:backgroundStacked"
    <item name="android:backgroundSplit"

And you need to have same style for api 7-10. It will be located in res/values/styles.xml, BUT because that api levels don't yet know about original android actionbar style items, we should use one, provided by support library. ActionBar Compat items are defined just like original android, but without "android:" part in the front:

<style name="Theme.Styled" parent="@style/Theme.AppCompat.Light">
    <!-- Setting values in the default namespace affects API levels 7-11 -->
    <item name="actionBarStyle">@style/Widget.Styled.ActionBar</item>

<style name="Widget.Styled.ActionBar" parent="@style/Widget.AppCompat.Light.ActionBar">
    <!-- Setting values in the default namespace affects API levels 7-11 -->
    <item name="background">@drawable/ab_custom_solid_styled</item>
    <item name="backgroundStacked">@drawable/ab_custom_stacked_solid_styled</item>
    <item name="backgroundSplit">@drawable/ab_custom_bottom_solid_styled</item>

Please mark that, even if api levels higher than 10 already have actionbar you should still use AppCompat styles. If you don't, you will have this error on launch of Acitvity on devices with android 3.0 and higher:

java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.

Here is link this original article written by Chris Banes.

P.S. Sorry for my English

PHP parse/syntax errors; and how to solve them

An error message that begins Parse error: syntax error, unexpected ':' can be caused by mistakenly writing a class static reference Class::$Variable as Class:$Variable.

sendUserActionEvent() is null

I also encuntered the same in S4. I've tested the app in Galaxy Grand , HTC , Sony Experia but got only in s4. You can ignore it as its not related to your app.

Git push results in "Authentication Failed"

If you enabled two-factor authentication in your Github account you won't be able to push via HTTPS using your accounts password. Instead you need to generate a personal access token. This can be done in the application settings of your Github account. Using this token as your password should allow you to push to your remote repository via HTTPS. Use your username as usual.

You may also need to update the origin for your repository if set to https:

git remote -v 
git remote remove origin 
git remote add origin [email protected]:user/repo.git  

How to display count of notifications in app launcher icon

I have figured out how this is done for Sony devices.

I've blogged about it here. I've also posted a seperate SO question about this here.

Sony devices use a class named BadgeReciever.

  1. Declare the com.sonyericsson.home.permission.BROADCAST_BADGE permission in your manifest file:

  2. Broadcast an Intent to the BadgeReceiver:

    Intent intent = new Intent();
    intent.putExtra("com.sonyericsson.home.intent.extra.badge.ACTIVITY_NAME", "com.yourdomain.yourapp.MainActivity");
    intent.putExtra("com.sonyericsson.home.intent.extra.badge.SHOW_MESSAGE", true);
    intent.putExtra("com.sonyericsson.home.intent.extra.badge.MESSAGE", "99");
    intent.putExtra("com.sonyericsson.home.intent.extra.badge.PACKAGE_NAME", "com.yourdomain.yourapp");
  3. Done. Once this Intent is broadcast the launcher should show a badge on your application icon.

  4. To remove the badge again, simply send a new broadcast, this time with SHOW_MESSAGE set to false:

    intent.putExtra("com.sonyericsson.home.intent.extra.badge.SHOW_MESSAGE", false);

I've excluded details on how I found this to keep the answer short, but it's all available in the blog. Might be an interesting read for someone.

How to get the path of running java program

    ClassLoader cl = ClassLoader.getSystemClassLoader();

    URL[] urls = ((URLClassLoader)cl).getURLs();

    for(URL url: urls){

How to edit/save a file through Ubuntu Terminal

Within Nano use Ctrl+O to save and Ctrl+X to exit if you were wondering

Javadoc link to method in other class

For the Javadoc tag @see, you don't need to use @link; Javadoc will create a link for you. Try


Here's more info about @see.

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver in Eclipse

It seems the mysql connectivity library is not included in the project. Solve the problem following one of the proposed solutions:


Add the mysql-connector dependency to the pom.xml project file:


Here you are all the versions:


Add the jar library manually to the project.

Right Click the project -- > build path -- > configure build path

In Libraries Tab press Add External Jar and Select your jar.

You can find zip for mysql-connector here

  • Explanation:

When building the project, java throws you an exception because a file (the com.mysql.jdbc.Driver class) from the mysql connectivity library is not found. The solution is adding the library to the project, and java will find the com.mysql.jdbc.Driver

Android open pdf file

The problem is that there is no app installed to handle opening the PDF. You should use the Intent Chooser, like so:

File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath() +"/"+ filename);
Intent target = new Intent(Intent.ACTION_VIEW);

Intent intent = Intent.createChooser(target, "Open File");
try {
} catch (ActivityNotFoundException e) {
    // Instruct the user to install a PDF reader here, or something

javax.crypto.IllegalBlockSizeException : Input length must be multiple of 16 when decrypting with padded cipher

Well that is Because of

you are only able to encrypt data in blocks of 128 bits or 16 bytes. That's why you are getting that IllegalBlockSizeException exception. and the one way is to encrypt that data Directly into the String.

look this. Try and u will be able to resolve this

public static String decrypt(String encryptedData) throws Exception {

    Key key = generateKey();
    Cipher c = Cipher.getInstance(ALGO);
    c.init(Cipher.DECRYPT_MODE, key);
    String decordedValue = new BASE64Decoder().decodeBuffer(encryptedData).toString().trim();
    System.out.println("This is Data to be Decrypted" + decordedValue);
    return decordedValue;

hope that will help.

JavaFX Location is not set error message

The answer below by CsPeitch and others is on the right track. Just make sure that the fxml file is being copied over to your class output target, or the runtime will not see it. Check the generated class file directory and see if the fxml is there

Failed to load ApplicationContext for JUnit test of Spring controller

Solved by adding the following dependency into pom.xml file :


WhatsApp API (java/python)

WhatsApp Inc. does not provide an open API but a reverse-engineered library is made available on GitHub by the team Venomous on the GitHub. This however according to my knowledge is made possible in PHP. You can check the link here:

Hope this helps

Embed Youtube video inside an Android app

there is an official YouTube Android Player API wich you can use. This is a bit more complicated but it is working better than other solutions using webclients.

First you must register your app in Googles API Console. This is completely free until your app gets over 25k request a month (or something like that). There are complete anf great tutorials under the link. I hope you can understand them. If not, ask! :)

Change background color of selected item on a ListView

If you want to have the item remain highlighted after you have clicked it, you need to manually set it as being selected in the onItemClick listener

Android ListView selected item stay highlighted:

myList.setOnItemClickListener(new OnItemClickListener() {
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {   
        view.setSelected(true); // <== Will cause the highlight to remain
        //... do more stuff                          

This assumes you have a state_selected item in your selector:

<?xml version="1.0" encoding="utf-8"?>
  <selector xmlns:android="">  
  <item android:state_enabled="true" android:state_pressed="true" android:drawable="@color/red" />
  <item android:state_enabled="true" android:state_focused="true" android:drawable="@color/red" />
  <item android:state_enabled="true" android:state_selected="true" android:drawable="@color/red" />
  <item android:drawable="@color/white" />

Selenium WebDriver findElement(By.xpath()) not working for me

Correct Xpath syntax is like:


So you should write something like this:


OnClickListener in Android Studio

Button button= (Button) findViewById(;
button.setOnClickListener(new View.OnClickListener() {
    public void onClick(View v) {
        startActivity(new Intent(MainActivity.this,StandingsActivity.class));

This code is not in any method. If you want to use it, it must be within a method like OnCreate()

protected void onCreate(Bundle savedInstanceState) {

    Button button= (Button) findViewById(;
    button.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            startActivity(new Intent(MainActivity.this,StandingsActivity.class));

"Insufficient Storage Available" even there is lot of free space in device memory

The same problem was coming for my phone and this resolved the problem:

  • Go to Application Manager/ Apps from Settings.

  • Select Google Play Services.

Enter image description here

  • Click Uninstall Updates button to the right of the Force Stop button.

  • Once the updates are uninstalled, you should see Disable button which means you are done.

Enter image description here

You will see lots of free space available now.

Angularjs Template Default Value if Binding Null / Undefined (With Filter)

I made the following filter:

angular.module('app').filter('ifEmpty', function() {
    return function(input, defaultValue) {
        if (angular.isUndefined(input) || input === null || input === '') {
            return defaultValue;

        return input;

To be used like this:

<span>{{aPrice | currency | ifEmpty:'N/A'}}</span>
<span>{{aNum | number:3 | ifEmpty:0}}</span>

python 3.2 UnicodeEncodeError: 'charmap' codec can't encode character '\u2013' in position 9629: character maps to <undefined>

While Python 3 deals in Unicode, the Windows console or POSIX tty that you're running inside does not. So, whenever you print, or otherwise send Unicode strings to stdout, and it's attached to a console/tty, Python has to encode it.

The error message indirectly tells you what character set Python was trying to use:

  File "C:\Python32\lib\encodings\", line 19, in encode

This means the charset is cp850.

You can test or yourself that this charset doesn't have the appropriate character just by doing '\u2013'.encode('cp850'). Or you can look up cp850 online (e.g., at Wikipedia).

It's possible that Python is guessing wrong, and your console is really set for, say UTF-8. (In that case, just manually set sys.stdout.encoding='utf-8'.) It's also possible that you intended your console to be set for UTF-8 but did something wrong. (In that case, you probably want to follow up at

But if nothing is wrong, you just can't print that character. You will have to manually encode it with one of the non-strict error-handlers. For example:

>>> '\u2013'.encode('cp850')
UnicodeEncodeError: 'charmap' codec can't encode character '\u2013' in position 0: character maps to <undefined>
>>> '\u2013'.encode('cp850', errors='replace')

So, how do you print a string that won't print on your console?

You can replace every print function with something like this:

>>> print(r['body'].encode('cp850', errors='replace').decode('cp850'))

… but that's going to get pretty tedious pretty fast.

The simple thing to do is to just set the error handler on sys.stdout:

>>> sys.stdout.errors = 'replace'
>>> print(r['body'])

For printing to a file, things are pretty much the same, except that you don't have to set f.errors after the fact, you can set it at construction time. Instead of this:

with open('path', 'w', encoding='cp850') as f:

Do this:

with open('path', 'w', encoding='cp850', errors='replace') as f:

… Or, of course, if you can use UTF-8 files, just do that, as Mark Ransom's answer shows:

with open('path', 'w', encoding='utf-8') as f:

Junit test case for database insert method with DAO and web service

The design of your classes will make it hard to test them. Using hardcoded connection strings or instantiating collaborators in your methods with new can be considered as test-antipatterns. Have a look at the DependencyInjection pattern. Frameworks like Spring might be of help here.

To have your DAO tested you need to have control over your database connection in your unit tests. So the first thing you would want to do is extract it out of your DAO into a class that you can either mock or point to a specific test database, which you can setup and inspect before and after your tests run.

A technical solution for testing db/DAO code might be dbunit. You can define your test data in a schema-less XML and let dbunit populate it in your test database. But you still have to wire everything up yourself. With Spring however you could use something like spring-test-dbunit which gives you lots of leverage and additional tooling.

As you call yourself a total beginner I suspect this is all very daunting. You should ask yourself if you really need to test your database code. If not you should at least refactor your code, so you can easily mock out all database access. For mocking in general, have a look at Mockito.

Dependency injection with Jersey 2.0

If you prefer to use Guice and you don't want to declare all the bindings, you can also try this adapter:


Syntax error: Illegal return statement in JavaScript

If you want to return some value then wrap your statement in function

function my_function(){ 

 return my_thing; 

Problem is with the statement on the 1st line if you are trying to use PHP

var ask = confirm ('".$message."'); 

IF you are trying to use PHP you should use

 var ask = confirm (<?php echo "'".$message."'" ?>); //now message with be the javascript string!!

How can I make a JUnit test wait?

There is a general problem: it's hard to mock time. Also, it's really bad practice to place long running/waiting code in a unit test.

So, for making a scheduling API testable, I used an interface with a real and a mock implementation like this:

public interface Clock {
    public long getCurrentMillis();
    public void sleep(long millis) throws InterruptedException;

public static class SystemClock implements Clock {

    public long getCurrentMillis() {
        return System.currentTimeMillis();

    public void sleep(long millis) throws InterruptedException {

public static class MockClock implements Clock {

    private final AtomicLong currentTime = new AtomicLong(0);

    public MockClock() {
    public MockClock(long currentTime) {

    public long getCurrentMillis() {
        return currentTime.addAndGet(5);

    public void sleep(long millis) {

With this, you could imitate time in your test:

public void testExpiration() {
    MockClock clock = new MockClock();
    SomeCacheObject sco = new SomeCacheObject();
    sco.putWithExpiration("foo", 1000);
    clock.sleep(2000) // wait for 2 seconds

An advanced multi-threading mock for Clock is much more complex, of course, but you can make it with ThreadLocal references and a good time synchronization strategy, for example.

Using HTML data-attribute to set CSS background-image url

How about using some Sass? Here's what I did to achieve something like this (although note that you have to create a Sass list for each of the data-attributes).

  Iterate over list and use "data-social" to put in the appropriate background-image.
$social: "fb", "twitter", "youtube";

@each $i in $social {
  [data-social="#{$i}"] {
    background: url('#{$image-path}/icons/#{$i}.svg') no-repeat 0 0;
    background-size: cover; // Only seems to work if placed below background property

Essentially, you list all of your data attribute values. Then use Sass @each to iterate through and select all the data-attributes in the HTML. Then, bring in the iterator variable and have it match up to a filename.

Anyway, as I said, you have to list all of the values, then make sure that your filenames incorporate the values in your list.

Changing image sizes proportionally using CSS?

transform: scale(0.5);


<div class="scaled">Scaled</div>
div {
  width: 80px;
  height: 80px;
  background-color: skyblue;

.scaled {
  transform: scale(0.7); /* Equal to scaleX(0.7) scaleY(0.7) */
  background-color: pink;


fatal: 'origin' does not appear to be a git repository

I faced the same problem when I renamed my repository on GitHub. I tried to push at which point I got the error

fatal: 'origin' does not appear to be a git repository
fatal: The remote end hung up unexpectedly

I had to change the URL using

git remote set-url origin ssh://[email protected]/username/newRepoName.git

After this all commands started working fine. You can check the change by using

git remote -v

In my case after successfull change it showed correct renamed repo in URL

[aniket@alok Android]$ git remote -v
origin  ssh://[email protected]/aniket91/TicTacToe.git (fetch)
origin  ssh://[email protected]/aniket91/TicTacToe.git (push)

Git push error: "origin does not appear to be a git repository"

I had this problem cause i had already origin remote defined locally. So just change "origin" into another name:

git remote add originNew

git push -u originNew

or u can remove your local origin. to check your remote name type:

git remote

to remove remote - log in your clone repository and type:

git remote remove origin(depending on your remote's name)

How to convert ActiveRecord results into an array of hashes

May be?

If you need symbols keys: { |r| r.attributes.symbolize_keys }

How do I correct this Illegal String Offset?

I get the same error in WP when I use php ver 7.1.6 - just take your php version back to 7.0.20 and the error will disappear.

When should an IllegalArgumentException be thrown?

The API doc for IllegalArgumentException:

Thrown to indicate that a method has been passed an illegal or inappropriate argument.

From looking at how it is used in the JDK libraries, I would say:

  • It seems like a defensive measure to complain about obviously bad input before the input can get into the works and cause something to fail halfway through with a nonsensical error message.

  • It's used for cases where it would be too annoying to throw a checked exception (although it makes an appearance in the java.lang.reflect code, where concern about ridiculous levels of checked-exception-throwing is not otherwise apparent).

I would use IllegalArgumentException to do last ditch defensive argument checking for common utilities (trying to stay consistent with the JDK usage). Or where the expectation is that a bad argument is a programmer error, similar to an NullPointerException. I wouldn't use it to implement validation in business code. I certainly wouldn't use it for the email example.

Getting the error "Java.lang.IllegalStateException Activity has been destroyed" when using tabs with ViewPager

I had this problem and I couldn't find the solution here, so I want to share my solution in case someone else has this problem again.

I had this code:

public void finishAction() {

and solved the problem by deleting the line "onDestroy();"

public void finishAction() {

The reason I wrote the initial code: I know that when you execute "finish()" the activity calls "onDestroy()", but I'm using threads and I wanted to ensure that all the threads are destroyed before starting the next activity, and it looks like "finish()" is not always immediate. I need to process/reduce a lot of “Bitmap” and display big “bitmaps” and I’m working on improving the use of the memory in my app

Now I will kill the threads using a different method and I’ll execute this method from "onDestroy();" and when I think I need to kill all the threads.

public void finishAction() {

Understanding Bootstrap's clearfix class

The :before pseudo element isn't needed for the clearfix hack itself.

It's just an additional nice feature helping to prevent margin-collapsing of the first child element. Thus the top margin of an child block element of the "clearfixed" element is guaranteed to be positioned below the top border of the clearfixed element.

display:table is being used because display:block doesn't do the trick. Using display:block margins will collapse even with a :before element.

There is one caveat: if vertical-align:baseline is used in table cells with clearfixed <div> elements, Firefox won't align well. Then you might prefer using display:block despite loosing the anti-collapsing feature. In case of further interest read this article: Clearfix interfering with vertical-align.

OpenVPN failed connection / All TAP-Win32 adapters on this system are currently in use

It seems to me you are using the wrong version...

TAP-Win32 should not be installed on the 64bit version. Download the right one and try again!

Uri not Absolute exception getting while calling Restful Webservice

An absolute URI specifies a scheme; a URI that is not absolute is said to be relative.

So, perhaps your URLEncoder isn't working as you're expecting (the https bit)?


Can't access Eclipse marketplace

in my case: i got a new pc and I had to download and install a brand new eclipse. by default the proxy was set to native. I was getting that error at first. I then changed it to active. And still it didn't work. And then i put it back to "native" and it worked.

How can I perform an inspect element in Chrome on my Galaxy S3 Android device?

Keep in mind that if you want to use the chrome inspect in Windows, besides enabling usb debugging on you mobile, you should also install the usb driver for Windows.

You can find the drivers you need from the list here:

Furthermore, you should use a newer version of Chrome mobile than the one in your Desktop.

Why Git is not allowing me to commit even after configuration?

Do you have a local or that's overriding the global one?

git config --list --global | grep user NAME
git config --list --local | grep user NAME

If so, remove them

git config --unset --local
git config --unset --local

The local settings are per-clone, so you'll have to unset the local and for each of the repos on your machine.

capture div into image using html2canvas didn't work for me... just a blank page rendered... but I was able to make the png appear on the page by replacing the src attribute of a pre-existing img element created as the target.

     element_to_png("container", "testhtmltocanvasimg");_x000D_
function element_to_png(srcElementID, targetIMGid){_x000D_
    console.log("element_to_png called for element id " + srcElementID);_x000D_
    html2canvas($("#"+srcElementID)[0]).then( function (canvas) {_x000D_
        var myImage = canvas.toDataURL("image/png");_x000D_
        $("#"+targetIMGid).attr("src", myImage);_x000D_
  console.log("html2canvas completed.  png rendered to " + targetIMGid);_x000D_
<div id="testhtmltocanvasdiv" class="mt-3">_x000D_
   <img src="" id="testhtmltocanvasimg">_x000D_

I can then right-click on the rendered png and "save as". May be just as easy to use the "snipping tool" to capture the element, but html2canvas is an certainly an interesting bit of code!

DLL Load Library - Error Code 126

This can also happen when you're trying to load a DLL and that in turn needs another DLL which cannot be not found.

Passing data through intent using Serializable

I extended ??s???? K's answer to make the code full and workable. So, when you finish filling your 'all_thumbs' list, you should put its content one by one into the bundle and then into the intent:

Bundle bundle = new Bundle();

for (int i = 0; i<all_thumbs.size(); i++)
bundle.putSerializable("extras"+i, all_thumbs.get(i));


In order to get the extras from the intent, you need:

Bundle bundle = new Bundle();
List<Thumbnail> thumbnailObjects = new ArrayList<Thumbnail>();

// collect your Thumbnail objects
for (String key : bundle.keySet()) {
thumbnailObjects.add((Thumbnail) bundle.getSerializable(key));

// for example, in order to get a value of the 3-rd object you need to:
String label = thumbnailObjects.get(2).get_label();

Advantage of Serializable is its simplicity. However, I would recommend you to consider using Parcelable method when you need transfer many data, because Parcelable is specifically designed for Android and it is more efficient than Serializable. You can create Parcelable class using:

  1. an online tool - parcelabler
  2. a plugin for Android Studion - Android Parcelable code generator

Responsive web design is working on desktop but not on mobile device

You are probably missing the viewport meta tag in the html head:

 <meta name="viewport" content="width=device-width, initial-scale=1">

Without it the device assumes and sets the viewport to full size.

More info here.

What is the "Illegal Instruction: 4" error and why does "-mmacosx-version-min=10.x" fix it?

I got this error when attempting to build with Xcode 10. It appears to be a bug in the Swift compiler. Building with Whole Module Optimization on, resolves the issue:

This is not an ideal solution, I will continue to use Xcode 9.4.1 until this issue is resolved.

java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState

My app has a fragment to loading in 3 secs, but when the fist screen is preparing to show, I press home button and resume run it, it show the same error, so It edit my code and it ran very smooth:

new Handler().post(new Runnable() {
        public void run() {
            if (saveIns == null) {
                mFragment = new Fragment_S1_loading();
                        .replace(, mFragment).commit();
            // Loading screen in 3 secs:
            mCountDownTimerLoading = new CountDownTimer(3000, 1000) {

                public void onTick(long millisUntilFinished) {


                public void onFinish() {
                    if (saveIns == null) {// TODO bug when start app and press home
                                            // button
                                        new Fragment_S2_sesstion1()).commitAllowingStateLoss();

NOTE: add commitAllowingStateLoss() instead of commit()

Duplicate ID, tag null, or parent id with another fragment for

For those who are still running into this issue, the best way to make sure you don't get this error with a Map in a Tab is to make the Fragment extend SupportMapFragment instead of nesting a SupportMapFragment inside the Fragment used for the Tab.

I just got this working using a ViewPager with a FragmentPagerAdapter, with the SupportMapFragment in the third Tab.

Here is the general structure, note there is no need to override the onCreateView() method, and there is no need to inflate any layout xml:

public class MapTabFragment extends SupportMapFragment 
                                    implements OnMapReadyCallback {

    private GoogleMap mMap;
    private Marker marker;

    public MapTabFragment() {

    public void onResume() {


    private void setUpMapIfNeeded() {

        if (mMap == null) {


    public void onMapReady(GoogleMap googleMap) {

        mMap = googleMap;

    private void setUpMap() {


        mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {

            public void onMapClick(LatLng point) {

                //remove previously placed Marker
                if (marker != null) {

                //place marker where user just clicked
                marker = mMap.addMarker(new MarkerOptions().position(point).title("Marker")





enter image description here

Here is the full class code that I used to test with, which includes the placeholder Fragment used for the first two Tabs, and the Map Fragment used for the third Tab:

public class MainActivity extends AppCompatActivity implements ActionBar.TabListener{

    SectionsPagerAdapter mSectionsPagerAdapter;

    ViewPager mViewPager;

    protected void onCreate(Bundle savedInstanceState) {

        mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());

        // Set up the ViewPager with the sections adapter.
        mViewPager = (ViewPager) findViewById(;

        final ActionBar actionBar = getSupportActionBar();

        mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
            public void onPageSelected(int position) {

        for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {


    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(, menu);
        return true;

    public boolean onOptionsItemSelected(MenuItem item) {

        int id = item.getItemId();

        if (id == {
            return true;

        return super.onOptionsItemSelected(item);

    public void onTabSelected(ActionBar.Tab tab, FragmentTransaction ft) {

    public void onTabUnselected(ActionBar.Tab tab, FragmentTransaction ft) {


    public void onTabReselected(ActionBar.Tab tab, FragmentTransaction ft) {


    public class SectionsPagerAdapter extends FragmentPagerAdapter {

        public SectionsPagerAdapter(FragmentManager fm) {

        public Fragment getItem(int position) {

            switch (position) {
                case 0:
                    return PlaceholderFragment.newInstance(position + 1);
                case 1:
                    return PlaceholderFragment.newInstance(position + 1);
                case 2:
                    return MapTabFragment.newInstance(position + 1);

            return null;

        public int getCount() {
            // Show 3 total pages.
            return 3;

        public CharSequence getPageTitle(int position) {
            Locale l = Locale.getDefault();

            switch (position) {
                case 0:
                    return getString(R.string.title_section1).toUpperCase(l);
                case 1:
                    return getString(R.string.title_section2).toUpperCase(l);
                case 2:
                    return getString(R.string.title_section3).toUpperCase(l);
            return null;

    public static class PlaceholderFragment extends Fragment {

        private static final String ARG_SECTION_NUMBER = "section_number";

        TextView text;

        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            return fragment;

        public PlaceholderFragment() {

        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);

            text = (TextView) rootView.findViewById(;

            return rootView;

    public static class MapTabFragment extends SupportMapFragment implements
            OnMapReadyCallback {

        private static final String ARG_SECTION_NUMBER = "section_number";

        private GoogleMap mMap;
        private Marker marker;

        public static MapTabFragment newInstance(int sectionNumber) {
            MapTabFragment fragment = new MapTabFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            return fragment;

        public MapTabFragment() {

        public void onResume() {

            Log.d("MyMap", "onResume");

        private void setUpMapIfNeeded() {

            if (mMap == null) {

                Log.d("MyMap", "setUpMapIfNeeded");


        public void onMapReady(GoogleMap googleMap) {
            Log.d("MyMap", "onMapReady");
            mMap = googleMap;

        private void setUpMap() {


            mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {

                public void onMapClick(LatLng point) {

                    Log.d("MyMap", "MapClick");

                    //remove previously placed Marker
                    if (marker != null) {

                    //place marker where user just clicked
                    marker = mMap.addMarker(new MarkerOptions().position(point).title("Marker")

                    Log.d("MyMap", "MapClick After Add Marker");



Autowiring fails: Not an managed Type

For me the error was quite simple based on what @alfred_m said..... tomcat had 2 jars conflicting having same set of Class names and configuration.

What happened was ..............I copied my existing project to make a new project out of the existing project. but without making required changes, I started working on other project. Henec 2 projects had same classes and configuration files, resulting into conflict.

Deleted the copied project and things started working!!!!

Android: How do bluetooth UUIDs work?

It usually represents some common service (protocol) that bluetooth device supports.

When creating your own rfcomm server (with listenUsingRfcommWithServiceRecord), you should specify your own UUID so that the clients connecting to it could identify it; it is one of the reasons why createRfcommSocketToServiceRecord requires an UUID parameter.

Otherwise, some common services have the same UUID, just find one you need and use it.

See here

jQuery: Check if special characters exists in string

If you really want to check for all those special characters, it's easier to use a regular expression:

var str = $('#Search').val();
if(/^[a-zA-Z0-9- ]*$/.test(str) == false) {
    alert('Your search string contains illegal characters.');

The above will only allow strings consisting entirely of characters on the ranges a-z, A-Z, 0-9, plus the hyphen an space characters. A string containing any other character will cause the alert.

React Native fixed footer

Simple stuff here:

Incase you don't need a ScrollView for this approach you can go with the below code to achieve Something like this :

Something like this

<View style={{flex: 1, backgroundColor:'grey'}}>
    <View style={{flex: 1, backgroundColor: 'red'}} />
    <View style={{height: 100, backgroundColor: 'green'}} />

Removing spaces from a variable input using PowerShell 4.0

The Replace operator means Replace something with something else; do not be confused with removal functionality.

Also you should send the result processed by the operator to a variable or to another operator. Neither .Replace(), nor -replace modifies the original variable.

To remove all spaces, use 'Replace any space symbol with empty string'

$string = $string -replace '\s',''

To remove all spaces at the beginning and end of the line, and replace all double-and-more-spaces or tab symbols to spacebar symbol, use

$string = $string -replace '(^\s+|\s+$)','' -replace '\s+',' '

or the more native System.String method

$string = $string.Trim()

Regexp is preferred, because ' ' means only 'spacebar' symbol, and '\s' means 'spacebar, tab and other space symbols'. Note that $string.Replace() does 'Normal' replace, and $string -replace does RegEx replace, which is more heavy but more functional.

Note that RegEx have some special symbols like dot (.), braces ([]()), slashes (\), hats (^), mathematical signs (+-) or dollar signs ($) that need do be escaped. ( '' -replace '\.','-' => 'my-space-com'. A dollar sign with a number (ex $1) must be used on a right part with care

'2033' -replace '(\d+)',$( 'Data: $1')
Data: 2033

UPDATE: You can also use $str = $str.Trim(), along with TrimEnd() and TrimStart(). Read more at System.String MSDN page.

How to solve : SQL Error: ORA-00604: error occurred at recursive SQL level 1

One possible explanation is a database trigger that fires for each DROP TABLE statement. To find the trigger, query the _TRIGGERS dictionary views:

select * from all_triggers
where trigger_type in ('AFTER EVENT', 'BEFORE EVENT')

disable any suspicious trigger with

   alter trigger <trigger_name> disable;

and try re-running your DROP TABLE statement

Unix epoch time to Java Date object

How about just:

Date expiry = new Date(Long.parseLong(date));

EDIT: as per rde6173's answer and taking a closer look at the input specified in the question , "1081157732" appears to be a seconds-based epoch value so you'd want to multiply the long from parseLong() by 1000 to convert to milliseconds, which is what Java's Date constructor uses, so:

Date expiry = new Date(Long.parseLong(date) * 1000);

Python syntax for "if a or b or c but not all of them"

If you mean a minimal form, go with this:

if (not a or not b or not c) and (a or b or c):

Which translates the title of your question.

UPDATE: as correctly said by Volatility and Supr, you can apply De Morgan's law and obtain equivalent:

if (a or b or c) and not (a and b and c):

My advice is to use whichever form is more significant to you and to other programmers. The first means "there is something false, but also something true", the second "There is something true, but not everything". If I were to optimize or do this in hardware, I would choose the second, here just choose the most readable (also taking in consideration the conditions you will be testing and their names). I picked the first.

How to get the <html> tag HTML with JavaScript / jQuery?

In jQuery:

var html_string = $('html').outerHTML()

In plain Javascript:

var html_string = document.documentElement.outerHTML

How do you find the current user in a Windows environment?

In a standard context, each connected user holds an explorer.exe process: The command [tasklist /V|find "explorer"] returns a line that contains the explorer.exe process owner's, with an adapted regex it is possible to obtain the required value. This also runs perfectly under Windows 7.

In rare cases explorer.exe is replaced by another program, the find filter can be adapted to match this case. If the command return an empty line then it is likely that no user is logged on. With Windows 7 it is also possible to run [query session|find ">"].

Generic Property in C#

You just declare the property the normal way using a generic type:

public MyType<string> PropertyName { get; set; }

If you want to call predefined methods to do something in the get or set, implement the property getter/setter to call those methods.

xlrd.biffh.XLRDError: Excel xlsx file; not supported

As noted in the release email, linked to from the release tweet and noted in large orange warning that appears on the front page of the documentation, and less orange, but still present, in the readme on the repository and the release on pypi:

xlrd has explicitly removed support for anything other than xls files.

In your case, the solution is to:

  • make sure you are on a recent version of Pandas, at least 1.0.1, and preferably the latest release. 1.2 will make his even clearer.
  • install openpyxl:
  • change your Pandas code to be:
    df1 = pd.read_excel(
         os.path.join(APP_PATH, "Data", "aug_latest.xlsm"),

Why doesn't Git ignore my specified file?

Another possible reasona few instances of git clients running at the same time. For example "git shell" + "GitHub Desktop", etc.

This happened to me, I was using "GitHub Desktop" as the main client and it was ignoring some new .gitignore settings: commit after commit:

  1. You commit something.
  2. Next, commit: it ignores .gitignore settings. Commit includes lots of temp files mentioned in the .gitignore.
  3. Clear git cache; check whether .gitignore is UTF8; remove files -> commit -> move files back; skip 1 commit – nothing helped.

Reason: the Visual Studio Code editor was running in the background with the same opened repository. VS Code has built-in git control, and this makes some conflicts.

Solution: double-check multiple, hidden git clients and use only one git client at once, especially while clearing git cache.

Make a Bash alias that takes a parameter?

Both functions and aliases can use parameters as others have shown here. Additionally, I would like to point out a couple of other aspects:

1. function runs in its own scope, alias shares scope

It may be useful to know this difference in cases you need to hide or expose something. It also suggests that a function is the better choice for encapsulation.

function tfunc(){
    GlobalFromFunc="Global From Func" # Function set global variable by default
    local FromFunc="onetwothree from func" # Set a local variable


alias talias='local LocalFromAlias="Local from Alias";  GlobalFromAlias="Global From Alias" # Cant hide a variable with local here '
# Test variables set by tfunc
tfunc # call tfunc
echo $GlobalFromFunc # This is visible
echo $LocalFromFunc # This is not visible
# Test variables set by talias
# call talias
echo $GlobalFromAlias # This is invisible
echo $LocalFromAlias # This variable is unset and unusable 


bash-3.2$     # Test variables set by tfunc
bash-3.2$     tfunc # call tfunc
bash-3.2$     echo $GlobalFromFunc # This is visible
Global From Func
bash-3.2$     echo $LocalFromFunc # This is not visible

bash-3.2$     # Test variables set by talias
bash-3.2$     # call talias
bash-3.2$     talias
bash: local: can only be used in a function
bash-3.2$     echo $GlobalFromAlias # This is invisible
Global From Alias
bash-3.2$ echo $LocalFromAlias # This variable is unset and unusable

2. wrapper script is a better choice

It has happened to me several times that an alias or function can not be found when logging in via ssh or involving switching usernames or multi-user environment. There are tips and tricks with sourcing dot files, or this interesting one with alias: alias sd='sudo ' lets this subsequent alias alias install='sd apt-get install' work as expect (notice the extra space in sd='sudo '). However, a wrapper script works better than a function or alias in cases like this. The main advantage with a wrapper script is that it is visible/executable for under intended path (i.e. /usr/loca/bin/) where as a function/alias needs to be sourced before it is usable. For example, you put a function in a ~/.bash_profile or ~/.bashrc for bash, but later switch to another shell (i.e. zsh) then the function is not visible anymore. So, when you are in doubt, a wrapper script is always the most reliable and portable solution.

Android adding simple animations while setvisibility(view.Gone)

Find the below code to make visible the view in Circuler reveal, if you send true, it'll get Invisible/Gone. If you send false, it'll get visible. anyView is the view you're going to visible/hide, it could be any view (Layouts, Buttons etc)

 private fun toggle(flag: Boolean, anyView: View) {
    if (flag) {
        val cx = anyView.width / 2
        val cy = anyView.height / 2
        val initialRadius = Math.hypot(cx.toDouble(), cy.toDouble()).toFloat()
        val anim = ViewAnimationUtils.createCircularReveal(anyView, cx, cy, initialRadius, 0f)
        anim.addListener(object : AnimatorListenerAdapter() {
            override fun onAnimationEnd(animation: Animator) {
                anyView.visibility = View.INVISIBLE
    } else {
        val cx = anyView.width / 2
        val cy = anyView.height / 2
        val finalRadius = Math.hypot(cx.toDouble(), cy.toDouble()).toFloat()
        val anim = ViewAnimationUtils.createCircularReveal(anyView, cx, cy, 0f, finalRadius)
        anyView.visibility = View.VISIBLE

How do I use CSS with a ruby on rails application?

Put the CSS files in public/stylesheets and then use:

<%= stylesheet_link_tag "filename" %>

to link to the stylesheet in your layouts or erb files in your views.

Similarly you put images in public/images and javascript files in public/javascripts.

Get the position of a spinner in Android

    final int[] positions=new int[2]; 
    Spinner sp=findViewByID(;

    sp.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {

        public void onItemSelected(AdapterView<?> arg0, View arg1,
                int arg2, long arg3) {
            // TODO Auto-generated method stub
            Toast.makeText( arg2....);

        public void onNothingSelected(AdapterView<?> arg0) {
            // TODO Auto-generated method stub


'this' vs $scope in AngularJS controllers

The reason 'addPane' is assigned to this is because of the <pane> directive.

The pane directive does require: '^tabs', which puts the tabs controller object from a parent directive, into the link function.

addPane is assigned to this so that the pane link function can see it. Then in the pane link function, addPane is just a property of the tabs controller, and it's just tabsControllerObject.addPane. So the pane directive's linking function can access the tabs controller object and therefore access the addPane method.

I hope my explanation is clear enough.. it's kind of hard to explain.

Get last 30 day records from today date in SQL Server

you can use this to get the data of the last 30 days based on a column.


SQL Server Insert if not exists

instead of below Code

   INSERT INTO EmailsRecebidos (De, Assunto, Data)
   WHERE NOT EXISTS ( SELECT * FROM EmailsRecebidos 
                   WHERE De = @_DE
                   AND Assunto = @_ASSUNTO
                   AND Data = @_DATA);

replace with

   IF NOT EXISTS (SELECT * FROM EmailsRecebidos 
                   WHERE De = @_DE
                   AND Assunto = @_ASSUNTO
                   AND Data = @_DATA)
       INSERT INTO EmailsRecebidos (De, Assunto, Data)
       VALUES (@_DE, @_ASSUNTO, @_DATA)

Updated : (thanks to @Marc Durdin for pointing)

Note that under high load, this will still sometimes fail, because a second connection can pass the IF NOT EXISTS test before the first connection executes the INSERT, i.e. a race condition. See for a good answer on why even wrapping in a transaction doesn't solve this.

changing visibility using javascript

Use display instead of visibility. display: none for invisible and no setting for visible.

Vertically aligning text next to a radio button

You may try something like;

<p><input type="radio" id="oddsPref" name="oddsPref" value="decimal" /><span>Decimal</span></p>

and give the span a margin top like;

    margin-top: 4px;

here is the fiddle

Random shuffling of an array

Look at the Collections class, specifically shuffle(...).

Changing cell color using apache poi

To create your cell styles see:

Custom colors


HSSFWorkbook wb = new HSSFWorkbook();
HSSFSheet sheet = wb.createSheet();
HSSFRow row = sheet.createRow((short) 0);
HSSFCell cell = row.createCell((short) 0);
cell.setCellValue("Default Palette");

//apply some colors from the standard palette,
// as in the previous examples.
//we'll use red text on a lime background

HSSFCellStyle style = wb.createCellStyle();

HSSFFont font = wb.createFont();


//save with the default palette
FileOutputStream out = new FileOutputStream("default_palette.xls");

//now, let's replace RED and LIME in the palette
// with a more attractive combination
// (lovingly borrowed from

cell.setCellValue("Modified Palette");

//creating a custom palette for the workbook
HSSFPalette palette = wb.getCustomPalette();

//replacing the standard red with red
        (byte) 153,  //RGB red (0-255)
        (byte) 0,    //RGB green
        (byte) 0     //RGB blue
//replacing lime with gold
palette.setColorAtIndex(HSSFColor.LIME.index, (byte) 255, (byte) 204, (byte) 102);

//save with the modified palette
// note that wherever we have previously used RED or LIME, the
// new colors magically appear
out = new FileOutputStream("modified_palette.xls");


 XSSFWorkbook wb = new XSSFWorkbook();
    XSSFSheet sheet = wb.createSheet();
    XSSFRow row = sheet.createRow(0);
    XSSFCell cell = row.createCell( 0);
    cell.setCellValue("custom XSSF colors");

    XSSFCellStyle style1 = wb.createCellStyle();
    style1.setFillForegroundColor(new XSSFColor(new java.awt.Color(128, 0, 128)));

Python None comparison: should I use "is" or ==?


Use is when you want to check against an object's identity (e.g. checking to see if var is None). Use == when you want to check equality (e.g. Is var equal to 3?).


You can have custom classes where my_var == None will return True


class Negator(object):
    def __eq__(self,other):
        return not other

thing = Negator()
print thing == None    #True
print thing is None    #False

is checks for object identity. There is only 1 object None, so when you do my_var is None, you're checking whether they actually are the same object (not just equivalent objects)

In other words, == is a check for equivalence (which is defined from object to object) whereas is checks for object identity:

lst = [1,2,3]
lst == lst[:]  # This is True since the lists are "equivalent"
lst is lst[:]  # This is False since they're actually different objects

Writing a dict to txt file and reading it back?

Your code is almost right! You are right, you are just missing one step. When you read in the file, you are reading it as a string; but you want to turn the string back into a dictionary.

The error message you saw was because self.whip was a string, not a dictionary.

I first wrote that you could just feed the string into dict() but that doesn't work! You need to do something else.


Here is the simplest way: feed the string into eval(). Like so:

def reading(self):
    s = open('deed.txt', 'r').read()
    self.whip = eval(s)

You can do it in one line, but I think it looks messy this way:

def reading(self):
    self.whip = eval(open('deed.txt', 'r').read())

But eval() is sometimes not recommended. The problem is that eval() will evaluate any string, and if someone tricked you into running a really tricky string, something bad might happen. In this case, you are just running eval() on your own file, so it should be okay.

But because eval() is useful, someone made an alternative to it that is safer. This is called literal_eval and you get it from a Python module called ast.

import ast

def reading(self):
    s = open('deed.txt', 'r').read()
    self.whip = ast.literal_eval(s)

ast.literal_eval() will only evaluate strings that turn into the basic Python types, so there is no way that a tricky string can do something bad on your computer.


Actually, best practice in Python is to use a with statement to make sure the file gets properly closed. Rewriting the above to use a with statement:

import ast

def reading(self):
    with open('deed.txt', 'r') as f:
        s =
        self.whip = ast.literal_eval(s)

In the most popular Python, known as "CPython", you usually don't need the with statement as the built-in "garbage collection" features will figure out that you are done with the file and will close it for you. But other Python implementations, like "Jython" (Python for the Java VM) or "PyPy" (a really cool experimental system with just-in-time code optimization) might not figure out to close the file for you. It's good to get in the habit of using with, and I think it makes the code pretty easy to understand.

Formatting html email for Outlook

I used VML(Vector Markup Language) based formatting in my email template. In VML Based you have write your code within comment I took help from this site.

How do I see active SQL Server connections?

Below is my script to find all the sessions connected to a database and you can check if those sessions are doing any I/O and there is an option to kill them.

The script shows also the status of each session.

Have a look below.

-- See who is connected to the database.
-- Analyse what each spid is doing, reads and writes.
-- If safe you can copy and paste the killcommand - last column.
-- Marcelo Miorelli
-- 18-july-2017 - London (UK)
-- Tested on SQL Server 2016.
USE master


    ,KillCommand  = 'Kill '+ CAST(sdes.session_id  AS VARCHAR)
FROM sys.dm_exec_sessions AS sdes

INNER JOIN sys.dm_exec_connections AS sdec
        ON sdec.session_id = sdes.session_id


    SELECT DB_NAME(dbid) AS DatabaseName
        ,OBJECT_NAME(objectid) AS ObjName
            SELECT TEXT AS [processing-instruction(definition)]
            FROM sys.dm_exec_sql_text(sdec.most_recent_sql_handle)
            FOR XML PATH('')
            ), '') AS Query

    FROM sys.dm_exec_sql_text(sdec.most_recent_sql_handle)

) sdest
WHERE sdes.session_id <> @@SPID
  AND sdest.DatabaseName ='yourdatabasename'
--ORDER BY sdes.last_request_start_time DESC


Why, Fatal error: Class 'PHPUnit_Framework_TestCase' not found in ...?

For higher version of phpunit such as 6.4 You must use the namespace PHPUnit\Framework\TestCase

use TestCase instead PHPUnit_Framework_TestCase

// use the following namespace
use PHPUnit\Framework\TestCase;

// extend using TestCase instead PHPUnit_Framework_TestCase
class SampleTest extends TestCase {


Delete rows with blank values in one particular column

An easy approach would be making all the blank cells NA and only keeping complete cases. You might also look for na.omit examples. It is a widely discussed topic.


Java: String - add character n-times

Keep in mind that if the "n" is large, it might not be such a great idea to use +=, since every time you add another String through +=, the JVM will create a brand new object (plenty of info on this around).

Something like:

StringBuilder b = new StringBuilder(existing_string);
for(int i = 0; i<n; i++){
return b.toString();

Not actually coding this in an IDE, so minor flaws may occur, but this is the basic idea.

PreparedStatement with Statement.RETURN_GENERATED_KEYS

You mean something like this?

long key = -1L;

PreparedStatement preparedStatement = connection.prepareStatement(YOUR_SQL_HERE, PreparedStatement.RETURN_GENERATED_KEYS);
preparedStatement.setXXX(index, VALUE);

ResultSet rs = preparedStatement.getGeneratedKeys();

if ( {
    key = rs.getLong(1);

How to match, but not capture, part of a regex?



That will match apple, banana, or a blank string, and following it there will be a 0 or 1 hyphens. I was wrong about not having a need for a capturing group. Silly me.

How do I compare two strings in Perl?

See perldoc perlop. Use lt, gt, eq, ne, and cmp as appropriate for string comparisons:

Binary eq returns true if the left argument is stringwise equal to the right argument.

Binary ne returns true if the left argument is stringwise not equal to the right argument.

Binary cmp returns -1, 0, or 1 depending on whether the left argument is stringwise less than, equal to, or greater than the right argument.

Binary ~~ does a smartmatch between its arguments. ...

lt, le, ge, gt and cmp use the collation (sort) order specified by the current locale if a legacy use locale (but not use locale ':not_characters') is in effect. See perllocale. Do not mix these with Unicode, only with legacy binary encodings. The standard Unicode::Collate and Unicode::Collate::Locale modules offer much more powerful solutions to collation issues.

Remote Connections Mysql Ubuntu

MySQL only listens to localhost, if we want to enable the remote access to it, then we need to made some changes in my.cnf file:

sudo nano /etc/mysql/my.cnf

We need to comment out the bind-address and skip-external-locking lines:

#bind-address =
# skip-external-locking

After making these changes, we need to restart the mysql service:

sudo service mysql restart

Changing Fonts Size in Matlab Plots

To change the default property for your entire MATLAB session, see the documentation on how default properties are handled.

As an example:

x=1:200; y=sin(x);
title('hello'); xlabel('x'); ylabel('sin(x)')

fatal: git-write-tree: error building trees

This worked for me:


$ git status

And check if you have Unmerged paths

# Unmerged paths:
#   (use "git reset HEAD <file>..." to unstage)
#   (use "git add <file>..." to mark resolution)
#   both modified:      app/assets/images/logo.png
#   both modified:      app/models/laundry.rb

Fix them with git add to each of them and try git stash again.

git add app/assets/images/logo.png

PHP: Show yes/no confirmation dialog

You can handle the attribute onClick for both i.e. 'ok' & 'cancel' condition like ternary operator

Scenario: Here is the scenario that I wants to show confirm box which will ask for 'ok' or 'cancel' while performing a delete action. In that I want if user click on 'ok' then the form action will redirect to page location and on cancel page will not respond.

Adding further explanation i'm having one button with type="submit" which is originally use default form action of form tag. and I want above scenario on delete button with same input type.

So below code is working properly for me

onClick="return confirm('Are you sure you want to Delete ?')?this.form.action='<?php echo $_SERVER['PHP_SELF'] ?>':false;"

Full code

<input type="submit" name="action" id="Delete" value="Delete" onClick="return confirm('Are you sure you want to Delete ?')?this.form.action='<?php echo $_SERVER['PHP_SELF'] ?>':false;">

And by the way I'm implementing this code as inline in html element using PHP. so that's why I used 'echo $_SERVER['PHP_SELF']'.

I hope it will work for you also. Thank You

How to compute precision, recall, accuracy and f1-score for the multiclass case with scikit learn?

Posed question

Responding to the question 'what metric should be used for multi-class classification with imbalanced data': Macro-F1-measure. Macro Precision and Macro Recall can be also used, but they are not so easily interpretable as for binary classificaion, they are already incorporated into F-measure, and excess metrics complicate methods comparison, parameters tuning, and so on.

Micro averaging are sensitive to class imbalance: if your method, for example, works good for the most common labels and totally messes others, micro-averaged metrics show good results.

Weighting averaging isn't well suited for imbalanced data, because it weights by counts of labels. Moreover, it is too hardly interpretable and unpopular: for instance, there is no mention of such an averaging in the following very detailed survey I strongly recommend to look through:

Sokolova, Marina, and Guy Lapalme. "A systematic analysis of performance measures for classification tasks." Information Processing & Management 45.4 (2009): 427-437.

Application-specific question

However, returning to your task, I'd research 2 topics:

  1. metrics commonly used for your specific task - it lets (a) to compare your method with others and understand if you do something wrong, and (b) to not explore this by yourself and reuse someone else's findings;
  2. cost of different errors of your methods - for example, use-case of your application may rely on 4- and 5-star reviewes only - in this case, good metric should count only these 2 labels.

Commonly used metrics. As I can infer after looking through literature, there are 2 main evaluation metrics:

  1. Accuracy, which is used, e.g. in

Yu, April, and Daryl Chang. "Multiclass Sentiment Prediction using Yelp Business."

(link) - note that the authors work with almost the same distribution of ratings, see Figure 5.

Pang, Bo, and Lillian Lee. "Seeing stars: Exploiting class relationships for sentiment categorization with respect to rating scales." Proceedings of the 43rd Annual Meeting on Association for Computational Linguistics. Association for Computational Linguistics, 2005.


  1. MSE (or, less often, Mean Absolute Error - MAE) - see, for example,

Lee, Moontae, and R. Grafe. "Multiclass sentiment analysis with restaurant reviews." Final Projects from CS N 224 (2010).

(link) - they explore both accuracy and MSE, considering the latter to be better

Pappas, Nikolaos, Rue Marconi, and Andrei Popescu-Belis. "Explaining the Stars: Weighted Multiple-Instance Learning for Aspect-Based Sentiment Analysis." Proceedings of the 2014 Conference on Empirical Methods In Natural Language Processing. No. EPFL-CONF-200899. 2014.

(link) - they utilize scikit-learn for evaluation and baseline approaches and state that their code is available; however, I can't find it, so if you need it, write a letter to the authors, the work is pretty new and seems to be written in Python.

Cost of different errors. If you care more about avoiding gross blunders, e.g. assinging 1-star to 5-star review or something like that, look at MSE; if difference matters, but not so much, try MAE, since it doesn't square diff; otherwise stay with Accuracy.

About approaches, not metrics

Try regression approaches, e.g. SVR, since they generally outperforms Multiclass classifiers like SVC or OVA SVM.

Find objects between two dates MongoDB

i tried in this model as per my requirements i need to store a date when ever a object is created later i want to retrieve all the records (documents ) between two dates in my html file i was using the following format mm/dd/yyyy

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">


    $("#select_date").click(function() { 
    type: "post",
    url: "xxx", 
    datatype: "html",
    data: $("#period").serialize(),  
    success: function(data){
    } ,//success

    }); //event triggered



    <form id="period" name='period'>
        from <input id="selecteddate" name="selecteddate1" type="text"> to 
        <input id="select_date" type="button" value="selected">

in my py (python) file i converted it into "iso fomate" in following way

date_str1   = request.POST["SelectedDate1"] 
SelectedDate1   = datetime.datetime.strptime(date_str1, '%m/%d/%Y').isoformat()

and saved in my dbmongo collection with "SelectedDate" as field in my collection

to retrieve data or documents between to 2 dates i used following query

db.collection.find( "SelectedDate": {'$gte': SelectedDate1,'$lt': SelectedDate2}})

How to tell if a connection is dead in python

Short answer:

use a non-blocking recv(), or a blocking recv() / select() with a very short timeout.

Long answer:

The way to handle socket connections is to read or write as you need to, and be prepared to handle connection errors.

TCP distinguishes between 3 forms of "dropping" a connection: timeout, reset, close.

Of these, the timeout can not really be detected, TCP might only tell you the time has not expired yet. But even if it told you that, the time might still expire right after.

Also remember that using shutdown() either you or your peer (the other end of the connection) may close only the incoming byte stream, and keep the outgoing byte stream running, or close the outgoing stream and keep the incoming one running.

So strictly speaking, you want to check if the read stream is closed, or if the write stream is closed, or if both are closed.

Even if the connection was "dropped", you should still be able to read any data that is still in the network buffer. Only after the buffer is empty will you receive a disconnect from recv().

Checking if the connection was dropped is like asking "what will I receive after reading all data that is currently buffered ?" To find that out, you just have to read all data that is currently bufferred.

I can see how "reading all buffered data", to get to the end of it, might be a problem for some people, that still think of recv() as a blocking function. With a blocking recv(), "checking" for a read when the buffer is already empty will block, which defeats the purpose of "checking".

In my opinion any function that is documented to potentially block the entire process indefinitely is a design flaw, but I guess it is still there for historical reasons, from when using a socket just like a regular file descriptor was a cool idea.

What you can do is:

  • set the socket to non-blocking mode, but than you get a system-depended error to indicate the receive buffer is empty, or the send buffer is full
  • stick to blocking mode but set a very short socket timeout. This will allow you to "ping" or "check" the socket with recv(), pretty much what you want to do
  • use select() call or asyncore module with a very short timeout. Error reporting is still system-specific.

For the write part of the problem, keeping the read buffers empty pretty much covers it. You will discover a connection "dropped" after a non-blocking read attempt, and you may choose to stop sending anything after a read returns a closed channel.

I guess the only way to be sure your sent data has reached the other end (and is not still in the send buffer) is either:

  • receive a proper response on the same socket for the exact message that you sent. Basically you are using the higher level protocol to provide confirmation.
  • perform a successful shutdow() and close() on the socket

The python socket howto says send() will return 0 bytes written if channel is closed. You may use a non-blocking or a timeout socket.send() and if it returns 0 you can no longer send data on that socket. But if it returns non-zero, you have already sent something, good luck with that :)

Also here I have not considered OOB (out-of-band) socket data here as a means to approach your problem, but I think OOB was not what you meant.

How to generate a random number in C++?

Using modulo may introduce bias into the random numbers, depending on the random number generator. See this question for more info. Of course, it's perfectly possible to get repeating numbers in a random sequence.

Try some C++11 features for better distribution:

#include <random>
#include <iostream>

int main()
    std::random_device dev;
    std::mt19937 rng(dev());
    std::uniform_int_distribution<std::mt19937::result_type> dist6(1,6); // distribution in range [1, 6]

    std::cout << dist6(rng) << std::endl;

See this question/answer for more info on C++11 random numbers. The above isn't the only way to do this, but is one way.

How to change visibility of layout programmatically

TextView view = (TextView) findViewById(;
view.setText("Add your text here");

When use getOne and findOne methods Spring Data JPA

1. Why does the getOne(id) method fail?

See this section in the docs. You overriding the already in place transaction might be causing the issue. However, without more info this one is difficult to answer.

2. When I should use the getOne(id) method?

Without digging into the internals of Spring Data JPA, the difference seems to be in the mechanism used to retrieve the entity.

If you look at the JavaDoc for getOne(ID) under See Also:

See Also:
EntityManager.getReference(Class, Object)

it seems that this method just delegates to the JPA entity manager's implementation.

However, the docs for findOne(ID) do not mention this.

The clue is also in the names of the repositories. JpaRepository is JPA specific and therefore can delegate calls to the entity manager if so needed. CrudRepository is agnostic of the persistence technology used. Look here. It's used as a marker interface for multiple persistence technologies like JPA, Neo4J etc.

So there's not really a 'difference' in the two methods for your use cases, it's just that findOne(ID) is more generic than the more specialised getOne(ID). Which one you use is up to you and your project but I would personally stick to the findOne(ID) as it makes your code less implementation specific and opens the doors to move to things like MongoDB etc. in the future without too much refactoring :)

Official reasons for "Software caused connection abort: socket write error"

My server was throwing this exception in the pass 2 days and I solved it by moving the disconnecting function with:


To the end of the listing thread. if it will helped anyone.

Execute SQLite script

In order to execute simple queries and return to my shell script, I think this works well:

$ sqlite3 example.db 'SELECT * FROM some_table;'

Trigger a button click with JavaScript on the Enter key in a text box

To trigger a search every time the enter key is pressed, use this:

$(document).keypress(function(event) {
    var keycode = (event.keyCode ? event.keyCode : event.which);
    if (keycode == '13') {

Correct way to use Modernizr to detect IE?

Modernizr doesn't detect browsers as such, it detects which feature and capability are present and this is the whole jist of what it's trying to do.

You could try hooking in a simple detection script like this and then using it to make your choice. I've included Version Detection as well just in case that's needed. If you only want to check of any version of IE you could just look for the navigator.userAgent having a value of "MSIE".

var BrowserDetect = {_x000D_
        init: function () {_x000D_
            this.browser = this.searchString(this.dataBrowser) || "Other";_x000D_
            this.version = this.searchVersion(navigator.userAgent) || this.searchVersion(navigator.appVersion) || "Unknown";_x000D_
        searchString: function (data) {_x000D_
            for (var i = 0; i < data.length; i++) {_x000D_
                var dataString = data[i].string;_x000D_
                this.versionSearchString = data[i].subString;_x000D_
                if (dataString.indexOf(data[i].subString) !== -1) {_x000D_
                    return data[i].identity;_x000D_
        searchVersion: function (dataString) {_x000D_
            var index = dataString.indexOf(this.versionSearchString);_x000D_
            if (index === -1) {_x000D_
            var rv = dataString.indexOf("rv:");_x000D_
            if (this.versionSearchString === "Trident" && rv !== -1) {_x000D_
                return parseFloat(dataString.substring(rv + 3));_x000D_
            } else {_x000D_
                return parseFloat(dataString.substring(index + this.versionSearchString.length + 1));_x000D_
        dataBrowser: [_x000D_
            {string: navigator.userAgent, subString: "Edge", identity: "MS Edge"},_x000D_
            {string: navigator.userAgent, subString: "MSIE", identity: "Explorer"},_x000D_
            {string: navigator.userAgent, subString: "Trident", identity: "Explorer"},_x000D_
            {string: navigator.userAgent, subString: "Firefox", identity: "Firefox"},_x000D_
            {string: navigator.userAgent, subString: "Opera", identity: "Opera"},  _x000D_
            {string: navigator.userAgent, subString: "OPR", identity: "Opera"},  _x000D_
            {string: navigator.userAgent, subString: "Chrome", identity: "Chrome"}, _x000D_
            {string: navigator.userAgent, subString: "Safari", identity: "Safari"}       _x000D_
    document.write("You are using <b>" + BrowserDetect.browser + "</b> with version <b>" + BrowserDetect.version + "</b>");

You can then simply check for:

BrowserDetect.browser == 'Explorer';
BrowserDetect.version <= 9;

How to use zIndex in react-native

I finally solved this by creating a second object that imitates B.

My schema now looks like this:

enter image description here

I now have B1 (within parent of A) and B2 outside of it.

B1 and B2 are right next to one another, so to the naked eye it looks as if it's just 1 object.

Is there a way to specify a default property value in Spring XML? points out that "local properties" defined on the bean itself will be considered defaults to be overridden by values read from files:

<bean id="propertyConfigurer"class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">  
  <property name="location"><value></value></property>  
  <property name="properties">  
      <prop key="entry.1">123</prop>  

assign value using linq

It can be done this way as well

foreach (Company company in listofCompany.Where(d => d.Id = 1)).ToList())
                    //do your stuff here
                    company.Id= 2;
                    company.Name= "Sample"

What is meant by Ems? (Android TextView)

em is basically CSS property for font sizes.

The em and ex units depend on the font and may be different for each element in the document. The em is simply the font size. In an element with a 2in font, 1em thus means 2in. Expressing sizes, such as margins and paddings, in em means they are related to the font size, and if the user has a big font (e.g., on a big screen) or a small font (e.g., on a handheld device), the sizes will be in proportion. Declarations such as text-indent: 1.5em and margin: 1em are extremely common in CSS.


Copy Image from Remote Server Over HTTP

Here's the most basic way:

$url = "http://other-site/image.png";
$dir = "/my/local/dir/";

$rfile = fopen($url, "r");
$lfile = fopen($dir . basename($url), "w");

while(!feof($url)) fwrite($lfile, fread($rfile, 1), 1);


But if you're doing lots and lots of this (or your host blocks file access to remote systems), consider using CURL, which is more efficient, mildly faster and available on more shared hosts.

You can also spoof the user agent to look like a desktop rather than a bot!

$url = "http://other-site/image.png";
$dir = "/my/local/dir/";
$lfile = fopen($dir . basename($url), "w");

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)');
curl_setopt($ch, CURLOPT_FILE, $lfile);


With both instances, you might want to pass it through GD to make sure it really is an image.

Escape @ character in razor view engine

Actually @ should be used with the Razor syntax Keywords or to the variable/model to bind a Value.

For Eg: if test is assigned with value i.e @ { var test = "ABC" } then you can get the value by settings as @test anywhere is cshtml page in html part. otherwise, simple use as @Html.DisplayName("test")

How to get key names from JSON using jq

To get the keys on a deeper node in an JSON:

echo '{"data": "1", "user": { "name": 2, "phone": 3 } }' | jq '.user | keys[]'

How can I run a PHP script inside a HTML file?

thanks for the ideas but none works here. So i did that... I am using xampp last version on 2014. go to \xampp\apache\conf\extra\httpd-xampp.conf.

we will find this bit of code:

<IfModule php5_module>
    **<FilesMatch "\.php$">**
        SetHandler application/x-httpd-php
    <FilesMatch "\.phps$">
        SetHandler application/x-httpd-php-source

    PHPINIDir "C:/xampp/php"

Focus on second line, so we must to change to:

<IfModule php5_module>
    **<FilesMatch "\.(php|html)$">**
        SetHandler application/x-httpd-php
    <FilesMatch "\.phps$">
        SetHandler application/x-httpd-php-source

    PHPINIDir "C:/xampp/php"

And that is it. Works good!

When is the @JsonProperty property used and what is it used for?

Here's a good example. I use it to rename the variable because the JSON is coming from a .Net environment where properties start with an upper-case letter.

public class Parameter {
  public String name;
  public String value; 

This correctly parses to/from the JSON:


How to delete a cookie?

Try this:

function delete_cookie( name, path, domain ) {
  if( get_cookie( name ) ) {
    document.cookie = name + "=" +
      ((path) ? ";path="+path:"")+
      ((domain)?";domain="+domain:"") +
      ";expires=Thu, 01 Jan 1970 00:00:01 GMT";

You can define get_cookie() like this:

function get_cookie(name){
    return document.cookie.split(';').some(c => {
        return c.trim().startsWith(name + '=');

How do I do top 1 in Oracle?

If you want just a first selected row, you can:

select fname from MyTbl where rownum = 1

You can also use analytic functions to order and take the top x:

select max(fname) over (rank() order by some_factor) from MyTbl

SQL Inner Join On Null Values

I'm pretty sure that the join doesn't even do what you want. If there are 100 records in table a with a null qid and 100 records in table b with a null qid, then the join as written should make a cross join and give 10,000 results for those records. If you look at the following code and run the examples, I think that the last one is probably more the result set you intended:

create table #test1 (id int identity, qid int)
create table #test2 (id int identity, qid int)

Insert #test1 (qid)
select null
union all
select null
union all
select 1
union all
select 2
union all
select null

Insert #test2 (qid)
select null
union all
select null
union all
select 1
union all
select 3
union all
select null

select * from #test2 t2
join #test1 t1 on t2.qid = t1.qid

select * from #test2 t2
join #test1 t1 on isnull(t2.qid, 0) = isnull(t1.qid, 0)

select * from #test2 t2
join #test1 t1 on 
 t1.qid = t2.qid OR ( t1.qid IS NULL AND t2.qid IS NULL )

select, t2.qid,, t1.qid from #test2 t2
join #test1 t1 on t2.qid = t1.qid
union all
select null, null,id, qid from #test1 where qid is null
union all
select id, qid, null, null from #test2  where qid is null

Get filename and path from URI from mediastore

Try This

Still, if you are getting the problem to get the real path, you can try my answers. Above answers didn't help me.

Explanation:- This method gets the URI and then check the API level of your Android device after that according to API level it will generate the Real path. Code for generating real path method is different according to API levels.

  1. method to get the Real path from URI

    public String getPathFromURI(Uri uri){
        String realPath="";
    // SDK < API11
        if (Build.VERSION.SDK_INT < 11) {
            String[] proj = { MediaStore.Images.Media.DATA };
            @SuppressLint("Recycle") Cursor cursor = getContentResolver().query(uri, proj, null, null, null);
            int column_index = 0;
            String result="";
            if (cursor != null) {
                column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
        // SDK >= 11 && SDK < 19
        else if (Build.VERSION.SDK_INT < 19){
            String[] proj = { MediaStore.Images.Media.DATA };
            CursorLoader cursorLoader = new CursorLoader(this, uri, proj, null, null, null);
            Cursor cursor = cursorLoader.loadInBackground();
            if(cursor != null){
                int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                realPath = cursor.getString(column_index);
        // SDK > 19 (Android 4.4)
            String wholeID = DocumentsContract.getDocumentId(uri);
            // Split at colon, use second item in the array
            String id = wholeID.split(":")[1];
            String[] column = { MediaStore.Images.Media.DATA };
            // where id is equal to
            String sel = MediaStore.Images.Media._ID + "=?";
            Cursor cursor = getContentResolver().query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, column, sel, new String[]{ id }, null);
            int columnIndex = 0;
            if (cursor != null) {
                columnIndex = cursor.getColumnIndex(column[0]);
                if (cursor.moveToFirst()) {
                    realPath = cursor.getString(columnIndex);
        return realPath;
  2. Use this method like this

    Log.e(TAG, "getRealPathFromURI: "+getPathFromURI(your_selected_uri) );


04-06 12:39:46.993 6138-6138/ E/tag: getRealPathFromURI: /storage/emulated/0/Video/avengers_infinity_war_4k_8k-7680x4320.jpg

getaddrinfo: nodename nor servname provided, or not known

The error occurs when the DNS resolution fails. Check if you can wget (or curl) the api url from the command line. Changing the DNS server and testing it might help.

What is the difference between a stored procedure and a view?

@Patrick is correct with what he said, but to answer your other questions a View will create itself in Memory, and depending on the type of Joins, Data and if there is any aggregation done, it could be a quite memory hungry View.

Stored procedures do all their processing either using Temp Hash Table e.g #tmpTable1 or in memory using @tmpTable1. Depending on what you want to tell it to do.

A Stored Procedure is like a Function, but is called Directly by its name. instead of Functions which are actually used inside a query itself.

Obviously most of the time Memory tables are faster, if you are not retrieveing alot of data.

How to list the tables in a SQLite database file that was opened with ATTACH?

There are a few steps to see the tables in an SQLite database:

  1. List the tables in your database:

  2. List how the table looks:

    .schema tablename
  3. Print the entire table:

    SELECT * FROM tablename;
  4. List all of the available SQLite prompt commands:


How do I merge a git tag onto a branch

I'm late to the game here, but another approach could be:

1) create a branch from the tag ($ git checkout -b [new branch name] [tag name])

2) create a pull-request to merge with your new branch into the destination branch

How do I merge my local uncommitted changes into another Git branch?

WARNING: Not for git newbies.

This comes up enough in my workflow that I've almost tried to write a new git command for it. The usual git stash flow is the way to go but is a little awkward. I usually make a new commit first since if I have been looking at the changes, all the information is fresh in my mind and it's better to just start git commit-ing what I found (usually a bugfix belonging on master that I discover while working on a feature branch) right away.

It is also helpful—if you run into situations like this a lot—to have another working directory alongside your current one that always have the master branch checked out.

So how I achieve this goes like this:

  1. git commit the changes right away with a good commit message.
  2. git reset HEAD~1 to undo the commit from current branch.
  3. (optional) continue working on the feature.

Sometimes later (asynchronously), or immediately in another terminal window:

  1. cd my-project-master which is another WD sharing the same .git
  2. git reflog to find the bugfix I've just made.
  3. git cherry-pick SHA1 of the commit.

Optionally (still asynchronous) you can then rebase (or merge) your feature branch to get the bugfix, usually when you are about to submit a PR and have cleaned your feature branch and WD already:

  1. cd my-project which is the main WD I'm working on.
  2. git rebase master to get the bugfixes.

This way I can keep working on the feature uninterrupted and not have to worry about git stash-ing anything or having to clean my WD before a git checkout (and then having the check the feature branch backout again.) and still have all my bugfixes goes to master instead of hidden in my feature branch.

IMO git stash and git checkout is a real PIA when you are in the middle of working on some big feature.

Python - Dimension of Data Frame

Summary of all ways to get info on dimensions of DataFrame or Series

There are a number of ways to get information on the attributes of your DataFrame or Series.

Create Sample DataFrame and Series

df = pd.DataFrame({'a':[5, 2, np.nan], 'b':[ 9, 2, 4]})

     a  b
0  5.0  9
1  2.0  2
2  NaN  4

s = df['a']

0    5.0
1    2.0
2    NaN
Name: a, dtype: float64

shape Attribute

The shape attribute returns a two-item tuple of the number of rows and the number of columns in the DataFrame. For a Series, it returns a one-item tuple.

(3, 2)


len function

To get the number of rows of a DataFrame or get the length of a Series, use the len function. An integer will be returned.



size attribute

To get the total number of elements in the DataFrame or Series, use the size attribute. For DataFrames, this is the product of the number of rows and the number of columns. For a Series, this will be equivalent to the len function:



ndim attribute

The ndim attribute returns the number of dimensions of your DataFrame or Series. It will always be 2 for DataFrames and 1 for Series:



The tricky count method

The count method can be used to return the number of non-missing values for each column/row of the DataFrame. This can be very confusing, because most people normally think of count as just the length of each row, which it is not. When called on a DataFrame, a Series is returned with the column names in the index and the number of non-missing values as the values.

df.count() # by default, get the count of each column

a    2
b    3
dtype: int64

df.count(axis='columns') # change direction to get count of each row

0    2
1    2
2    1
dtype: int64

For a Series, there is only one axis for computation and so it just returns a scalar:


Use the info method for retrieving metadata

The info method returns the number of non-missing values and data types of each column

<class 'pandas.core.frame.DataFrame'>
RangeIndex: 3 entries, 0 to 2
Data columns (total 2 columns):
a    2 non-null float64
b    3 non-null int64
dtypes: float64(1), int64(1)
memory usage: 128.0 bytes

TypeError: 'float' object is not callable

You have forgotten a * between -3.7 and (prof[x]).


for x in range(len(prof)):
    PB = 2.25 * (1 - math.pow(math.e, (-3.7 * (prof[x])/2.25))) * (math.e, (0/2.25)))

Also, there seems to be missing an ( as I count 6 times ( and 7 times ), and I think (math.e, (0/2.25)) is missing a function call (probably math.pow, but thats just a wild guess).

Convert numpy array to tuple

I was not satisfied, so I finally used this:

>>> a=numpy.array([[1,2,3],[4,5,6]])
>>> a
array([[1, 2, 3],
       [4, 5, 6]])

>>> tuple(a.reshape(1, -1)[0])
(1, 2, 3, 4, 5, 6)

I don't know if it's quicker, but it looks more effective ;)

How do you specify a byte literal in Java?

What about overriding the method with

void f(int value)

this will allow for f(0)

Select statement to find duplicates on certain fields

This is a fun solution with SQL Server 2005 that I like. I'm going to assume that by "for every record except for the first one", you mean that there is another "id" column that we can use to identify which row is "first".

    , field1
    , field2
    , field3
    SELECT id
        , field1
        , field2
        , field3
        , RANK() OVER (PARTITION BY field1, field2, field3 ORDER BY id ASC) AS [rank]
    FROM table_name
) a
WHERE [rank] > 1

Passing references to pointers in C++

&s produces temporary pointer to string and you can't make reference to temporary object.

Git is not working after macOS Update (xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools)

I got some errors that the software was unavailable from the update server when trying

xcode-select --install

What fixed it for me was going here and downloading Command Line Tools (macOS 10.14) for Xcode 10 and then installing it manually.

After that, the errors should be gone when you open up a new terminal.

How to combine results of two queries into a single dataset

Old question, but where others use JOIN to combine unrelated queries to rows in one table, this is my solution to combine unrelated queries to one row, e.g:

  (select count(*) c from v$session where program = 'w3wp.exe') w3wp,
  (select count(*) c from v$session) total,
from dual;

which gives the following one-row output:

-----  -----  -------------------
   14    290  2020/02/18 10:45:07

(which tells me that our web server currently uses 14 Oracle sessions out of the total of 290 sessions; I log this output without headers in an sqlplus script that runs every so many minutes)

How to add a “readonly” attribute to an <input>?

.attr('readonly', 'readonly') should do the trick. Your .attr('readonly') only returns the value, it doesn't set one.

Clearing an HTML file upload field via JavaScript

They don't get focus events, so you'll have to use a trick like this: only way to clear it is to clear the entire form

<script type="text/javascript">
    $(function() {
        $("#wrapper").bind("mouseover", function() {

<div id="wrapper">
    <input type=file value="" />

How to search a string in String array

Why the prohibition "I don't want to use any looping"? That's the most obvious solution. When given the chance to be obvious, take it!

Note that calls like arr.Contains(...) are still going to loop, it just won't be you who has written the loop.

Have you considered an alternate representation that's more amenable to searching?

  • A good Set implementation would perform well. (HashSet, TreeSet or the local equivalent).
  • If you can be sure that arr is sorted, you could use binary search (which would need to recurse or loop, but not as often as a straight linear search).

When to throw an exception?

Exception classes are like "normal" classes. You create a new class when it "is" a different type of object, with different fields and different operations.

As a rule of thumb, you should try balance between the number of exceptions and the granularity of the exceptions. If your method throws more than 4-5 different exceptions, you can probably merge some of them into more "general" exceptions, (e.g. in your case "AuthenticationFailedException"), and using the exception message to detail what went wrong. Unless your code handles each of them differently, you needn't creates many exception classes. And if it does, may you should just return an enum with the error that occured. It's a bit cleaner this way.

Joining Spark dataframes on the key

From, use join:

Inner equi-join with another DataFrame using the given column.



PersonDf.join(ProfileDf,PersonDf("personId") === ProfileDf("personId"))


You can also save the DFs as temp table using df.registerTempTable("tableName") and you can write sql queries using sqlContext.

What is Java EE?

J(2)EE, strictly speaking, is a set of APIs (as the current top answer has it) which enable a programmer to build distributed, transactional systems. The idea was to abstract away the complicated distributed, transactional bits (which would be implemented by a Container such as WebSphere or Weblogic), leaving the programmer to develop business logic free from worries about storage mechanisms and synchronization.

In reality, it was a cobbled-together, design-by-committee mish-mash, which was pushed pretty much for the benefit of vendors like IBM, Oracle and BEA so they could sell ridicously over-complicated, over-engineered, over-useless products. Which didn't have the most basic features (such as scheduling)!

J2EE was a marketing construct.

How to enable file upload on React's Material UI simple input?

If you're using React function components, and you don't like to work with labels or IDs, you can also use a reference.

const uploadInputRef = useRef(null);

return (
      style={{ display: "none" }}
      onClick={() => uploadInputRef.current &&}

UITableView with fixed section headers

You can also set the tableview's bounces property to NO. This will keep the section headers non-floating/static, but then you also lose the bounce property of the tableview.

How does functools partial do what it does?

Roughly, partial does something like this (apart from keyword args support etc):

def partial(func, *part_args):
    def wrapper(*extra_args):
        args = list(part_args)
        return func(*args)

    return wrapper

So, by calling partial(sum2, 4) you create a new function (a callable, to be precise) that behaves like sum2, but has one positional argument less. That missing argument is always substituted by 4, so that partial(sum2, 4)(2) == sum2(4, 2)

As for why it's needed, there's a variety of cases. Just for one, suppose you have to pass a function somewhere where it's expected to have 2 arguments:

class EventNotifier(object):
    def __init__(self):
        self._listeners = []

    def add_listener(self, callback):
        ''' callback should accept two positional arguments, event and params '''
        # ...

    def notify(self, event, *params):
        for f in self._listeners:
            f(event, params)

But a function you already have needs access to some third context object to do its job:

def log_event(context, event, params):
    context.log_event("Something happened %s, %s", event, params)

So, there are several solutions:

A custom object:

class Listener(object):
   def __init__(self, context):
       self._context = context

   def __call__(self, event, params):
       self._context.log_event("Something happened %s, %s", event, params)



log_listener = lambda event, params: log_event(context, event, params)

With partials:

context = get_context()  # whatever
notifier.add_listener(partial(log_event, context))

Of those three, partial is the shortest and the fastest. (For a more complex case you might want a custom object though).

PHP Get name of current directory




or (PHP5)


You can use basename() to get the trailing part of the path :)

In your case, I'd say you are most likely looking to use getcwd(), dirname(__FILE__) is more useful when you have a file that needs to include another library and is included in another library.



In your common.php you need to use functions in editor.php, so you use


require_once dirname(__FILE__) . '/images/editor.php';


require_once libs/common.php

That way when common.php is require'd in main.php, the call of require_once in common.php will correctly includes editor.php in images/editor.php instead of trying to look in current directory where main.php is run.

React Js conditionally applying class attributes

As others have commented, classnames utility is the currently recommended approach to handle conditional CSS class names in ReactJs.

In your case, the solution will look like:

var btnGroupClasses = classNames(
    'show': this.props.showBulkActions,
    'hidden': !this.props.showBulkActions


<div className={btnGroupClasses}>...</div>

As a side note, I would suggest you to try to avoid using both show and hidden classes, so the code could be simpler. Most likely you don't need to set a class for something to be shown by default.

Performing Breadth First Search recursively

Here's a python implementation:

graph = {'A': ['B', 'C'],
         'B': ['C', 'D'],
         'C': ['D'],
         'D': ['C'],
         'E': ['F'],
         'F': ['C']}

def bfs(paths, goal):
    if not paths:
        raise StopIteration

    new_paths = []
    for path in paths:
        if path[-1] == goal:
            yield path

        last = path[-1]
        for neighbor in graph[last]:
            if neighbor not in path:
                new_paths.append(path + [neighbor])
    yield from bfs(new_paths, goal)

for path in bfs([['A']], 'D'):

Why does intellisense and code suggestion stop working when Visual Studio is open?

I had the same issue, it turned out to be that nuget packages were not automatically downloaded for a solution i downloaded from the repository freshly, thus intellisense was not available since none of the required packages to show the right suggestions were available.

How to override the properties of a CSS class using another CSS class

LIFO is the way browser parses CSS properties..If you are using Sass declare a variable called as

"$header-background: red;"

use it instead of directly assigning values like red or blue. When you want to override just reassign the value to




it should smoothly override. Using "!important" is not always the right choice..Its just a hotfix

python re.split() to split by spaces, commas, and periods, but not in cases like 1,000 or 1.50

Use a negative lookahead and a negative lookbehind:

> s = "one two 3.4 5,6 seven.eight nine,ten"
> parts = re.split('\s|(?<!\d)[,.](?!\d)', s)
['one', 'two', '3.4', '5,6', 'seven', 'eight', 'nine', 'ten']

In other words, you always split by \s (whitespace), and only split by commas and periods if they are not followed (?!\d) or preceded (?<!\d) by a digit.


EDIT: As per @verdesmarald comment, you may want to use the following instead:

> s = "one two 3.4 5,6 seven.eight nine,ten,1.2,a,5"
> print re.split('\s|(?<!\d)[,.]|[,.](?!\d)', s)
['one', 'two', '3.4', '5,6', 'seven', 'eight', 'nine', 'ten', '1.2', 'a', '5']

This will split "1.2,a,5" into ["1.2", "a", "5"].


Right Align button in horizontal LinearLayout

try this one

 <?xml version="1.0" encoding="utf-8"?>
    android:orientation="horizontal"  >

  <RelativeLayout xmlns:android=""
   android:orientation="horizontal" >

    android:textSize="20sp" />

    android:text="add" />


Pycharm does not show plot

My env: macOS & anaconda3

This works for me:


or interactive mode:


DataTable: Hide the Show Entries dropdown but keep the Search box

You can try this also.

simply hide it from CSS by using,

 .dataTables_length {
        display: none;

Both will work.

How can you check for a #hash in a URL using JavaScript?

Most people are aware of the URL properties in document.location. That's great if you're only interested in the current page. But the question was about being able to parse anchors on a page not the page itself.

What most people seem to miss is that those same URL properties are also available to anchor elements:

// To process anchors on click    
jQuery('a').click(function () {
   if (this.hash) {
      // Clicked anchor has a hash
   } else {
      // Clicked anchor does not have a hash

// To process anchors without waiting for an event
jQuery('a').each(function () {
   if (this.hash) {
      // Current anchor has a hash
   } else {
      // Current anchor does not have a hash

Install php-mcrypt on CentOS 6


yum clean all
yum remove epel-release
yum install epel-release

and finally

yum install php-mcrypt

Sort hash by key, return hash in Ruby

You gave the best answer to yourself in the OP: Hash[h.sort] If you crave for more possibilities, here is in-place modification of the original hash to make it sorted:

h.keys.sort.each { |k| h[k] = h.delete k }

How to change value of a request parameter in laravel

If you need to customize the request

$data = $request->all();

you can pass the name of the field and the value

$data['product_ref_code'] = 1650;

and finally pass the new request

$last = Product::create($data);

Cannot deserialize the JSON array (e.g. [1,2,3]) into type ' ' because type requires JSON object (e.g. {"name":"value"}) to deserialize correctly

var objResponse1 = 


What is bootstrapping?

Alex, it's pretty much what your computer does when it boots up. ('Booting' a computer actually comes from the word bootstrapping)

Initially, the small program in your BIOS runs. That contains enough machine code to load and run a larger, more complex program.

That second program is probably something like NTLDR (in Windows) or LILO (in Linux), which then executes and is able to load, then run, the rest of the operating system.

Expansion of variables inside single quotes in a command in Bash

just use printf

instead of

repo forall -c '....$variable'

use printf to replace the variable token with the expanded variable.

For example:

template='.... %s'

repo forall -c $(printf "${template}" "${variable}")

JDK on OSX 10.7 Lion

For Mountain Lion, Apple's java is up to 1.6.0_35-b10-428.jdk as of today.
It is indeed located under /Library/Java/JavaVirtualMachines .

You just download
"Java for OS X 2012-005 Developer Package" (Sept 6, 2012)

In my view, Apple's naming is at least a bit confusing; why "-005" - is this the fifth version, or the fifth of five installers one needs?

And then run the installer; then follow the above steps inside Eclipse.

Centering the image in Bootstrap

Update 2018

Bootstrap 2.x

You could create a new CSS class such as:

.img-center {margin:0 auto;}

And then, add this to each IMG:

 <img src="images/2.png" class="img-responsive img-center">

OR, just override the .img-responsive if you're going to center all images..

 .img-responsive {margin:0 auto;}


Bootstrap 3.x

EDIT - With the release of Bootstrap 3.0.1, the center-block class can now be used without any additional CSS..

 <img src="images/2.png" class="img-responsive center-block">

Bootstrap 4

In Bootstrap 4, the mx-auto class (auto x-axis margins) can be used to center images that are display:block. However, img is display:inline by default so text-center can be used on the parent.

<div class="container">
    <div class="row">
        <div class="col-12">
            <img class="mx-auto d-block" src="//">  
    <div class="row">
        <div class="col-12 text-center">
            <img src="//">  

Bootsrap 4 - center image demo

What is the most effective way to get the index of an iterator of an std::vector?

I would prefer it - vec.begin() precisely for the opposite reason given by Naveen: so it wouldn't compile if you change the vector into a list. If you do this during every iteration, you could easily end up turning an O(n) algorithm into an O(n^2) algorithm.

Another option, if you don't jump around in the container during iteration, would be to keep the index as a second loop counter.

Note: it is a common name for a container iterator,std::container_type::iterator it;.

Catch multiple exceptions at once?

With C# 7 the answer from Michael Stum can be improved while keeping the readability of a switch statement:

catch (Exception ex)
    switch (ex)
        case FormatException _:
        case OverflowException _:
            WebId = Guid.Empty;

And with C# 8 as switch expression:

catch (Exception ex)
    WebId = ex switch
        _ when ex is FormatException || ex is OverflowException => Guid.Empty,
        _ => throw ex

Open files in 'rt' and 'wt' modes

The t indicates text mode, meaning that \n characters will be translated to the host OS line endings when writing to a file, and back again when reading. The flag is basically just noise, since text mode is the default.

Other than U, those mode flags come directly from the standard C library's fopen() function, a fact that is documented in the sixth paragraph of the python2 documentation for open().

As far as I know, t is not and has never been part of the C standard, so although many implementations of the C library accept it anyway, there's no guarantee that they all will, and therefore no guarantee that it will work on every build of python. That explains why the python2 docs didn't list it, and why it generally worked anyway. The python3 docs make it official.

How to remove an unpushed outgoing commit in Visual Studio?

Go to the Team Explorer tab then click Branches. In the branches select your branch from remotes/origin. For example, you want to reset your master branch. Right-click at the master branch in remotes/origin then select Reset then click Delete changes. This will reset your local branch and removes all locally committed changes.

Can HTML be embedded inside PHP "if" statement?

So if condition equals the value you want then the php document will run "include" and include will add that document to the current window for example:


$isARequest = true;
if ($isARequest){include('request.html');}/*So because $isARequest is true then it will include request.html but if its not a request then it will insert isNotARequest;*/
else if (!$isARequest) {include('isNotARequest.html')}


Proper way to exit iPhone application?

In addition to the above, good, answer I just wanted to add, think about cleaning up your memory.

After your application exits, the iPhone OS will automatically clean up anything your application left behind, so freeing all memory manually can just increase the amount of time it takes your application to exit.

Redirect within component Angular 2

    .subscribe(data => {
        this.getstud=data as string[];
        if(this.getstud.length!==0) {
            this.route.navigate(['home']);// used for routing after importing Router    

how does array[100] = {0} set the entire array to 0?

If your compiler is GCC you can also use following syntax:

int array[256] = {[0 ... 255] = 0};

Please look at, and note that this is a compiler-specific feature.

c - warning: implicit declaration of function ‘printf’

the warning or error of kind IMPLICIT DECLARATION is that the compiler is expecting a Function Declaration/Prototype..

It might either be a header file or your own function Declaration..

Make page to tell browser not to cache/preserve input values

Another approach would be to reset the form using JavaScript right after the form in the HTML:

<form id="myForm">
  <input type="text" value="" name="myTextInput" />

<script type="text/javascript">

How to check the function's return value if true or false

You don't need to call ValidateForm() twice, as you are above. You can just do

} else ...

I think that will solve the issue as above it looks like your comparing true/false to the string equivalent 'false'.

Excel: the Incredible Shrinking and Expanding Controls

After searching the net, it seams the best solution is saving the file as .xlsb (binary) rather than .xlsm

How to style a checkbox using CSS

I'd follow the advice of SW4's answer – to hide the checkbox and to cover it with a custom span, suggesting this HTML:

  <input type="checkbox">
  <span>send newsletter</span>

The wrap in label neatly allows clicking the text without the need of "for-id" attribute linking. However,

Do not hide it using visibility: hidden or display: none

It works by clicking or tapping, but that is a lame way to use checkboxes. Some people still use much more effective Tab to move focus, Space to activate, and hiding with that method disables it. If the form is long, one will save someone's wrists to use tabindex or accesskey attributes. And if you observe the system checkbox behavior, there is a decent shadow on hover. The well styled checkbox should follow this behavior.

cobberboy's answer recommends Font Awesome which is usually better than bitmap since fonts are scalable vectors. Working with the HTML above, I'd suggest these CSS rules:

  1. Hide checkboxes

     input[type="checkbox"] {
       position: absolute;
       opacity: 0;
       z-index: -1;

    I use just negative z-index since my example uses big enough checkbox skin to cover it fully. I don't recommend left: -999px since it is not reusable in every layout. Bushan wagh's answer provides a bulletproof way to hide it and convince the browser to use tabindex, so it is a good alternative. Anyway, both is just a hack. The proper way today is appearance: none, see Joost's answer:

     input[type="checkbox"] {
       appearance: none;
       -webkit-appearance: none;
       -moz-appearance: none;
  2. Style checkbox label

     input[type="checkbox"] + span {
       font: 16pt sans-serif;
       color: #000;
  3. Add checkbox skin

     input[type="checkbox"] + span:before {
       font: 16pt FontAwesome;
       content: '\00f096';
       display: inline-block;
       width: 16pt;
       padding: 2px 0 0 3px;
       margin-right: 0.5em;

\00f096 is Font Awesome's square-o, padding is adjusted to provide even dotted outline on focus (see below).

  1. Add checkbox checked skin

     input[type="checkbox"]:checked + span:before {
       content: '\00f046';

\00f046 is Font Awesome's check-square-o, which is not the same width as square-o, which is the reason for the width style above.

  1. Add focus outline

     input[type="checkbox"]:focus + span:before {
       outline: 1px dotted #aaa;

    Safari doesn't provide this feature (see @Jason Sankey's comment), see this answer for Safari-only CSS

  2. Set gray color for disabled checkbox

     input[type="checkbox"]:disabled + span {
       color: #999;
  3. Set hover shadow on non-disabled checkbox

     input[type="checkbox"]:not(:disabled) + span:hover:before {
       text-shadow: 0 1px 2px #77F;

Test it on JS Fiddle

Try to hover the mouse over the checkboxes and use Tab and Shift+Tab to move and Space to toggle.

What is the difference between vmalloc and kmalloc?

Short answer: download Linux Device Drivers and read the chapter on memory management.

Seriously, there are a lot of subtle issues related to kernel memory management that you need to understand - I spend a lot of my time debugging problems with it.

vmalloc() is very rarely used, because the kernel rarely uses virtual memory. kmalloc() is what is typically used, but you have to know what the consequences of the different flags are and you need a strategy for dealing with what happens when it fails - particularly if you're in an interrupt handler, like you suggested.

How update the _id of one MongoDB Document?

To do it for your whole collection you can also use a loop (based on Niels example):

    doc._id=doc.UserId; db.status_new.insert(doc);
db.status_new.renameCollection("status", true);

In this case UserId was the new ID I wanted to use

How can I read a text file from the SD card in Android?

You should have READ_EXTERNAL_STORAGE permission for reading sdcard. Add permission in manifest.xml

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

From android 6.0 or higher, your app must ask user to grant the dangerous permissions at runtime. Please refer this link Permissions overview

    if (checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 0);

List changes unexpectedly after assignment. How do I clone or copy it to prevent this?

I've been told that Python 3.3+ adds list.copy() method, which should be as fast as slicing:

newlist = old_list.copy()

How to enable mod_rewrite for Apache 2.2

New apache version has change in some way. If your apache version is 2.4 then you have to go to /etc/apache2/. There will be a file named apache2.conf. You have to edit that one(you should have root permission). Change directory text like this

<Directory /var/www/>
    Options Indexes FollowSymLinks
    AllowOverride All
    Require all granted

Now restart apache.

service apache2 reload

Hope it works.

PHP7 : install ext-dom issue

simply run

sudo apt install php-xml

its worked for me

Editing specific line in text file in Python

If your text contains only one individual:

import re

# creation
with open('pers.txt','wb') as g:
    g.write('Dan \n Warrior \n 500 \r\n 1 \r 0 ')

with open('pers.txt','rb') as h:
    print 'exact content of pers.txt before treatment:\n',repr(
with open('pers.txt','rU') as h:
    print '\nrU-display of pers.txt before treatment:\n',

# treatment
def roplo(file_name,what):
    patR = re.compile('^([^\r\n]+[\r\n]+)[^\r\n]+')
    with open(file_name,'rb+') as f:
        ch =

# after treatment
with open('pers.txt','rb') as h:
    print '\nexact content of pers.txt after treatment:\n',repr(
with open('pers.txt','rU') as h:
    print '\nrU-display of pers.txt after treatment:\n',

If your text contains several individuals:

import re

# creation
with open('pers.txt','wb') as g:
    g.write('Dan \n Warrior \n 500 \r\n 1 \r 0 \n Jim  \n  dragonfly\r300\r2\n10\r\nSomo\ncosmonaut\n490\r\n3\r65')

with open('pers.txt','rb') as h:
    print 'exact content of pers.txt before treatment:\n',repr(
with open('pers.txt','rU') as h:
    print '\nrU-display of pers.txt before treatment:\n',

# treatment
def ripli(file_name,who,what):
    with open(file_name,'rb+') as f:
        ch =
        x,y ='^\s*'+who+'\s*[\r\n]+([^\r\n]+)',ch,re.MULTILINE).span(1)

# after treatment
with open('pers.txt','rb') as h:
    print 'exact content of pers.txt after treatment:\n',repr(
with open('pers.txt','rU') as h:
    print '\nrU-display of pers.txt after treatment:\n',

If the “job“ of an individual was of a constant length in the texte, you could change only the portion of texte corresponding to the “job“ the desired individual: that’s the same idea as senderle’s one.

But according to me, better would be to put the characteristics of individuals in a dictionnary recorded in file with cPickle:

from cPickle import dump, load

with open('cards','wb') as f:

with open('cards','rb') as g:
    id_cards = load(g)
print 'id_cards before change==',id_cards

id_cards['Jim'][0] = 'Wizard'

with open('cards','w') as h:

with open('cards') as e:
    id_cards = load(e)
print '\nid_cards after change==',id_cards

vba error handling in loop

The problem is probably that you haven't resumed from the first error. You can't throw an error from within an error handler. You should add in a resume statement, something like the following, so VBA no longer thinks you are inside the error handler:

For Each oSheet In ActiveWorkbook.Sheets
    On Error GoTo NextSheet:
     Set qry = oSheet.ListObjects(1).QueryTable
     oCmbBox.AddItem oSheet.Name
    Resume NextSheet2
Next oSheet

Getting request payload from POST request in Java servlet

If you are able to send the payload in JSON, this is a most convenient way to read the playload:

Example data class:

public class Person {
    String firstName;
    String lastName;
    // Getters and setters ...

Example payload (request body):

{ "firstName" : "John", "lastName" : "Doe" }

Code to read payload in servlet (requires*):

Person person = new Gson().fromJson(request.getReader(), Person.class);

That's all. Nice, easy and clean. Don't forget to set the content-type header to application/json.

Replace contents of factor column in R dataframe

In case you have to replace multiple values and if you don't mind "refactoring" your variable with as.factor(as.character(...)) you could try the following:

replace.values <- function(search, replace, x){
  stopifnot(length(search) == length(replace))
  xnew <- replace[ match(x, search) ]
  takeOld <- & !
  xnew[takeOld] <- x[takeOld]

iris$Species <- as.factor(search=c("oldValue1","oldValue2"),

Using CookieContainer with WebClient class

The HttpWebRequest modifies the CookieContainer assigned to it. There is no need to process returned cookies. Simply assign your cookie container to every web request.

public class CookieAwareWebClient : WebClient
    public CookieContainer CookieContainer { get; set; } = new CookieContainer();

    protected override WebRequest GetWebRequest(Uri uri)
        WebRequest request = base.GetWebRequest(uri);
        if (request is HttpWebRequest)
            (request as HttpWebRequest).CookieContainer = CookieContainer;
        return request;

How to handle the new window in Selenium WebDriver using Java?

Set<String> windows = driver.getWindowHandles();
Iterator<String> itr = windows.iterator();

//patName will provide you parent window
String patName =;

//chldName will provide you child window
String chldName =;

//Switch to child window

//Do normal selenium code for performing action in child window

//To come back to parent window

What is the `data-target` attribute in Bootstrap 3?

The toggle tells Bootstrap what to do and the target tells Bootstrap which element is going to open. So whenever a link like that is clicked, a modal with an id of “basicModal” will appear.

Automatically resize images with browser size using CSS

image container

Scaling images using the above trick only works if the container the images are in changes size.

The #icons container uses px values for the width and height. px values don't scale when the browser is resized.


Use one of the following approaches:

  1. Define the width and/or height using % values.
  2. Use a series of @media queries to set the width and height to different values based on the current screen size.

Python: how to capture image from webcam on click using OpenCV

Here is a simple programe to capture a image from using laptop default camera.I hope that this will be very easy method for all.

import cv2

# 1.creating a video object
video = cv2.VideoCapture(0) 
# 2. Variable
a = 0
# 3. While loop
while True:
    a = a + 1
    # 4.Create a frame object
    check, frame =
    # Converting to grayscale
    #gray = cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)
    # the frame!
    # 6.for playing 
    key = cv2.waitKey(1)
    if key == ord('q'):
# 7. image saving
showPic = cv2.imwrite("filename.jpg",frame)
# 8. shutdown the camera

You can see my github code here

Get characters after last / in url

You could explode based on "/", and return the last entry:

print end( explode( "/", "" ) );

That's based on blowing the string apart, something that isn't necessary if you know the pattern of the string itself will not soon be changing. You could, alternatively, use a regular expression to locate that value at the end of the string:

$url = "";

if ( preg_match( "/\d+$/", $url, $matches ) ) {
    print $matches[0];

How to concatenate string variables in Bash

foo="${foo} World"
echo "${foo}"
> Hello World

In general to concatenate two variables you can just write them one after another:

c="${a} ${b}"
echo "${c}"
> Hello World

JS. How to replace html element with another element/text, represented in string?

If you need to actually replace the td you are selecting from the DOM, then you need to first go to the parentNode, then replace the contents replace the innerHTML with a new html string representing what you want. The trick is converting the first-table-cell to a string so you can then use it in a string replace method.

I added a fiddle example:

<table><tr><td id="first-table-cell">0</td><td>END</td></tr></table>

  var firstTableCell = document.getElementById('first-table-cell');
  var tableRow = firstTableCell.parentNode;
  // Create a separate node used to convert node into string.
  var renderingNode = document.createElement('tr');
  // Do a simple string replace on the html
  var stringVersionOfFirstTableCell = renderingNode.innerHTML;
  tableRow.innerHTML = tableRow.innerHTML.replace(stringVersionOfFirstTableCell,

A lot of the complexity here is that you are mixing DOM methods with string methods. If DOM methods work for your application, it would be much bette to use those. You can also do this with pure DOM methods (document.createElement, removeChild, appendChild), but it takes more lines of code and your question explicitly said you wanted to use a string.

How do I implement a callback in PHP?

For those who don't care about breaking compatibility with PHP < 5.4, I'd suggest using type hinting to make a cleaner implementation.

function call_with_hello_and_append_world( callable $callback )
     // No need to check $closure because of the type hint
     return $callback( "hello" )."world";

function append_space( $string )
     return $string." ";

$output1 = call_with_hello_and_append_world( function( $string ) { return $string." "; } );
var_dump( $output1 ); // string(11) "hello world"

$output2 = call_with_hello_and_append_world( "append_space" );
var_dump( $output2 ); // string(11) "hello world"

$old_lambda = create_function( '$string', 'return $string." ";' );
$output3 = call_with_hello_and_append_world( $old_lambda );
var_dump( $output3 ); // string(11) "hello world"

MySQL my.ini location

it is there at C:\Program Files\MySQL\MySQL Server 5.5 there are various .ini files with small, medium & large names. generally medium is used or it depends on your requirement.

Jquery $.ajax fails in IE on cross domain calls

Note, adding

$.support.cors = true;

was sufficient to force $.ajax calls to work on IE8

Already defined in .obj - no double inclusions

This is one of the method to overcome this issue.

  • Just put the prototype in the header files and include the header files in the .cpp files as shown below.


#include <boost/asio.hpp>

class SocketClient // Or whatever the name is... {

// ...

    bool read(int, char*); // Or whatever the name is...

//  ... };



bool SocketClient::read(int, char*)
    // Implementation  goes here...


#include <iostream>
#include <string>
#include <sstream>
#include <boost/asio.hpp>
#include <boost/thread/thread.hpp>
#include "client.h"
//              ^^ Notice this!


int main()

make div's height expand with its content

add a float property to the #main_content div - it will then expand to contain its floated contents

Execute write on doc: It isn't possible to write into a document from an asynchronously-loaded external script unless it is explicitly opened.

In case this is useful to anyone I had this same issue. I was bringing in a footer into a web page via jQuery. Inside that footer were some Google scripts for ads and retargeting. I had to move those scripts from the footer and place them directly in the page and that eliminated the notice.

How do I convert strings in a Pandas data frame to a 'date' data type?

I imagine a lot of data comes into Pandas from CSV files, in which case you can simply convert the date during the initial CSV read:

dfcsv = pd.read_csv('xyz.csv', parse_dates=[0]) where the 0 refers to the column the date is in.
You could also add , index_col=0 in there if you want the date to be your index.


font size in html code

There are a couple of answers posted here that will give you the text effects you want, but...

The thing about tables is that they are organized collections of labels and data. Having both a label ("Datum") and the value that it labels in the same cell is oh so very wrong. The label should be in a <th> element, with the value in a <td> either in the same row or the same column (depending on the data arrangement you are trying to achieve). You can have <th> elements running either vertically or horizontally or both, but if you don't have heading cells (which is what <th> means), you don't have a table, you just have a meaningless grid of text. It would be preferable, too, to have a <caption> element to label the table as a whole (you don't have to display the caption, but it should be there for accessibility) and have a summary="blah blah blah" attribute in the table tag, again for accessibility. So your HTML should probably look a lot more like this:

    <title>Test page with Table<title>
    <style type="text/css">
      th {
        font-size: 35px;
        font-weight: bold;
        padding-left: 5px;
        padding-bottom: 3px;
    <table id="table_1" summary="This table has both labels and values">
      <caption>Table of Stuff</caption>
        <td>November 2010</td>

That may not be exactly what you want -- it's hard to tell whether November 2010 is a data point or a label from what you've posted, and "Datum" isn't a helpful label in any case. Play with it a bit, but make sure that when your table is finished it actually has some kind of semantic meaning. If it's not a real table of data, then don't use a <table> to lay it out.

How can I change the font size using seaborn FacetGrid?

You can scale up the fonts in your call to sns.set().

import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
x = np.random.normal(size=37)
y = np.random.lognormal(size=37)

# defaults
fig, ax = plt.subplots()
ax.plot(x, y, marker='s', linestyle='none', label='small')
ax.legend(loc='upper left', bbox_to_anchor=(0, 1.1))

enter image description here

sns.set(font_scale=5)  # crazy big
fig, ax = plt.subplots()
ax.plot(x, y, marker='s', linestyle='none', label='big')
ax.legend(loc='upper left', bbox_to_anchor=(0, 1.3))

enter image description here

Refresh (reload) a page once using jQuery?

For refreshing page with javascript, you can simply use:


Meaning of 'const' last in a function declaration of a class?

These const mean that compiler will Error if the method 'with const' changes internal data.

class A

    int hashGetter() const
        state_ = 1;
        return member_;
    int goodGetter() const
        return member_;
    int getter() const
        //member_ = 2; // error
        return member_;
    int badGetter()
        return member_;
    mutable int state_;
    int member_;

The test

int main()
    const A a1;
    a1.badGetter(); // doesn't work
    a1.goodGetter(); // works
    a1.hashGetter(); // works

    A a2;
    a2.badGetter(); // works
    a2.goodGetter(); // works
    a2.hashGetter(); // works

Read this for more information

Link to add to Google calendar

I've also been successful with this URL structure:

Base URL:

And let's say this is my event details:

Title: Event Title
Description: Example of some description. See more at
Location: 123 Some Place
Date: February 22, 2020
Start Time: 10:00am
End Time: 11:30am
Timezone: America/New York (GMT -5)

I'd convert my details into these parameters (URL encoded):


Example link:

Please note that since I've specified a timezone with the "ctz" parameter, I used the local times for the start and end dates. Alternatively, you can use UTC dates and exclude the timezone parameter, like this:


Example link:

How to remove all duplicate items from a list

Use set():

woduplicates = set(lseparatedOrblist)

Returns a set without duplicates. If you, for some reason, need a list back:

woduplicates = list(set(lseperatedOrblist))

This will, however, have a different order than your original list.

Delaying AngularJS route change until model loaded to prevent flicker

I have had a complex multi-level sliding panel interface, with disabled screen layer. Creating directive on disable screen layer that would create click event to execute the state like


were producing a flicking effect. history.back() instead of it worked ok, however its not always back in history in my case. SO what I find out is that if I simply create attribute href on my disable screen instead of state.go , worked like a charm.

<a class="disable-screen" back></a>

Directive 'back'

app.directive('back', [ '$rootScope', function($rootScope) {

    return {
        restrict : 'A',
        link : function(scope, element, attrs) {
            element.attr('href', $rootScope.previousState.replace(/\./gi, '/'));

} ]);

app.js I just save previous state$rootScope, $state) {      

    $rootScope.$on("$stateChangeStart", function(event, toState, toParams, fromState, fromParams) {         

        $rootScope.previousState =;
        $rootScope.currentState =;


Creating a triangle with for loops

  for (int i=0; i<6; i++)
     for (int k=0; k<6-i; k++)
        System.out.print(" ");
     for (int j=0; j<i*2+1; j++)

How do I get the color from a hexadecimal color code using .NET?

There is also this neat little extension method:

static class ExtensionMethods
    public static Color ToColor(this uint argb)
        return Color.FromArgb((byte)((argb & -16777216)>> 0x18),      
                              (byte)((argb & 0xff0000)>> 0x10),   
                              (byte)((argb & 0xff00) >> 8),
                              (byte)(argb & 0xff));

In use:

Color color = 0xFFDFD991.ToColor();

Twitter Bootstrap tabs not working: when I click on them nothing happens

Had a problem with Bootstrap tabs recently following their online guidelines, but there's currently an error in their markup example data-tabs="tabs" is missing on <ul> element. Without it using data-toggle on links doesn't work.

Adding an assets folder in Android Studio

According to new Gradle based build system. We have to put assets under main folder.

Or simply right click on your project and create it like

File > New > folder > assets Folder

How To Convert A Number To an ASCII Character?

I was googling about how to convert an int to char, that got me here. But my question was to convert for example int of 6 to char of '6'. For those who came here like me, this is how to do it:

int num = 6;

Java web start - Unable to load resource

I've changed the java proxy settings to direct connection - and it works.

Test if remote TCP port is open from a shell script

nmap-ncat to test for local port that is not already in use

availabletobindon() {
  nc -w 2 -i 1 localhost "$port" 2>&1 | grep -v -q 'Idle timeout expired'
  return "$?"

How to force HTTPS using a web.config file

For those using ASP.NET MVC. You can use the RequireHttpsAttribute to force all responses to be HTTPS:

GlobalFilters.Filters.Add(new RequireHttpsAttribute());

Other things you may also want to do to help secure your site:

  1. Force Anti-Forgery tokens to use SSL/TLS:

    AntiForgeryConfig.RequireSsl = true;
  2. Require Cookies to require HTTPS by default by changing the Web.config file:

        <httpCookies httpOnlyCookies="true" requireSSL="true" />
  3. Use the NWebSec.Owin NuGet package and add the following line of code to enable Strict Transport Security (HSTS) across the site. Don't forget to add the Preload directive below and submit your site to the HSTS Preload site. More information here and here. Note that if you are not using OWIN, there is a Web.config method you can read up on on the NWebSec site.

    // app is your OWIN IAppBuilder app in Startup.cs
    app.UseHsts(options => options.MaxAge(days: 720).Preload());
  4. Use the NWebSec.Owin NuGet package and add the following line of code to enable Public Key Pinning (HPKP) across the site. More information here and here.

    // app is your OWIN IAppBuilder app in Startup.cs
    app.UseHpkp(options => options
            "Base64 encoded SHA-256 hash of your first certificate e.g. cUPcTAZWKaASuYWhhneDttWpY3oBAkE3h2+soZS7sWs=",
            "Base64 encoded SHA-256 hash of your second backup certificate e.g. M8HztCzM3elUxkcjR2S5P4hhyBNf6lHkmjAHKhpGPWE=")
        .MaxAge(days: 30));
  5. Include the https scheme in any URL's used. Content Security Policy (CSP) HTTP header and Subresource Integrity (SRI) do not play nice when you imit the scheme in some browsers. It is better to be explicit about HTTPS. e.g.

    <script src="">
  6. Use the ASP.NET MVC Boilerplate Visual Studio project template to generate a project with all of this and much more built in. You can also view the code on GitHub.

Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2

You state in the comments that the returned JSON is this:

  "dstOffset" : 3600, 
  "rawOffset" : 36000, 
  "status" : "OK", 
  "timeZoneId" : "Australia/Hobart", 
  "timeZoneName" : "Australian Eastern Daylight Time" 

You're telling Gson that you have an array of Post objects:

List<Post> postsList = Arrays.asList(gson.fromJson(reader,

You don't. The JSON represents exactly one Post object, and Gson is telling you that.

Change your code to be:

Post post = gson.fromJson(reader, Post.class);

How to decrypt an encrypted Apple iTunes iPhone backup?

Haven't tried it, but Elcomsoft released a product they claim is capable of decrypting backups, for forensics purposes. Maybe not as cool as engineering a solution yourself, but it might be faster.

Program to find prime numbers

It may just be my opinion, but there's another serious error in your program (setting aside the given 'prime number' question, which has been thoroughly answered).

Like the rest of the responders, I'm assuming this is homework, which indicates you want to become a developer (presumably).

You need to learn to compartmentalize your code. It's not something you'll always need to do in a project, but it's good to know how to do it.

Your method prime_num(long num) could stand a better, more descriptive name. And if it is supposed to find all prime numbers less than a given number, it should return them as a list. This makes it easier to seperate your display and your functionality.

If it simply returned an IList containing prime numbers you could then display them in your main function (perhaps calling another outside function to pretty print them) or use them in further calculations down the line.

So my best recommendation to you is to do something like this:

public void main(string args[])
    //Get the number you want to use as input
    long x = number;//'number' can be hard coded or retrieved from ReadLine() or from the given arguments

    IList<long> primes = FindSmallerPrimes(number);


public IList<long> FindSmallerPrimes(long largestNumber)
    List<long> returnList = new List<long>();
    //Find the primes, using a method as described by another answer, add them to returnList
    return returnList;

public void DisplayPrimes(IList<long> primes)
    foreach(long l in primes)
        Console.WriteLine ( "Prime:" + l.ToString() );

Even if you end up working somewhere where speration like this isn't needed, it's good to know how to do it.

AngularJS - add HTML element to dom in directive without jQuery

Why not to try simple (but powerful) html() method:

iElement.html('<svg width="600" height="100" class="svg"></svg>');

Or append as an alternative:

iElement.append('<svg width="600" height="100" class="svg"></svg>');

And , of course , more cleaner way:

 var svg = angular.element('<svg width="600" height="100" class="svg"></svg>');


Writing sqlplus output to a file

Also note that the SPOOL output is driven by a few SQLPlus settings:

  • SET LINESIZE nn - maximum line width; if the output is longer it will wrap to display the contents of each result row.

  • SET TRIMSPOOL OFF|ON - if set OFF (the default), every output line will be padded to LINESIZE. If set ON, every output line will be trimmed.

  • SET PAGESIZE nn - number of lines to output for each repetition of the header. If set to zero, no header is output; just the detail.

Those are the biggies, but there are some others to consider if you just want the output without all the SQLPlus chatter.

How to store a list in a column of a database table

you can store it as text that looks like a list and create a function that can return its data as an actual list. example:


|  word  | letters    |
|   me   | '[m, e]'   |
|  you   |'[y, o, u]' |  note that the letters column is of type 'TEXT'
|  for   |'[f, o, r]' |
|___in___|_'[i, n]'___|

And the list compiler function (written in python, but it should be easily translatable to most other programming languages). TEXT represents the text loaded from the sql table. returns list of strings from string containing list. if you want it to return ints instead of strings, make mode equal to 'int'. Likewise with 'string', 'bool', or 'float'.

def string_to_list(string, mode):
    items = []
    item = ""
    itemExpected = True
    for char in string[1:]:
        if itemExpected and char not in [']', ',', '[']:
            item += char
        elif char in [',', '[', ']']:
            itemExpected = True
            item = ""
    newItems = []
    if mode == "int":
        for i in items:

    elif mode == "float":
        for i in items:

    elif mode == "boolean":
        for i in items:
            if i in ["true", "True"]:
            elif i in ["false", "False"]:
    elif mode == "string":
        return items
        raise Exception("the 'mode'/second parameter of string_to_list() must be one of: 'int', 'string', 'bool', or 'float'")
    return newItems

Also here is a list-to-string function in case you need it.

def list_to_string(lst):
    string = "["
    for i in lst:
        string += str(i) + ","
    if string[-1] == ',':
        string = string[:-1] + "]"
        string += "]"
    return string

regular expression to validate datetime format (MM/DD/YYYY)

based on this


I modified the original to this:


test the regex here

Get current date in DD-Mon-YYY format in JavaScript/Jquery

Here's a simple solution, using TypeScript:

  convertDateStringToDate(dateStr) {
    //  Convert a string like '2020-10-04T00:00:00' into '4/Oct/2020'
    let months = ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'];
    let date = new Date(dateStr);
    let str = date.getDate()
                + '/' + months[date.getMonth()]
                + '/' + date.getFullYear()
    return str;

(Yeah, I know the question was about JavaScript, but I'm sure I won't be the only Angular developer coming across this article !)

Question mark characters displaying within text, why is this?

I usually curse MS word and then run the following Wscript.

// replace with path to a file that needs cleaning
PATH = "test.html"

var go=WScript.CreateObject("Scripting.FileSystemObject");
var content=go.GetFile(PATH).OpenAsTextStream().ReadAll();
var out=go.CreateTextFile("clean-"+PATH, true);

// symbols


How do I cancel an HTTP fetch() request?

As of Feb 2018, fetch() can be cancelled with the code below on Chrome (read Using Readable Streams to enable Firefox support). No error is thrown for catch() to pick up, and this is a temporary solution until AbortController is fully adopted.

.then(response => {
  if (!response.body) {
    console.warn("ReadableStream is not yet supported in this browser.  See")
    return response;

  // get reference to ReadableStream so we can cancel/abort this fetch request.
  const responseReader = response.body.getReader();

  // Return a new Response object that implements a custom reader.
  return new Response(new ReadableStream(new ReadableStreamConfig(responseReader)));
.then(response => response.blob())
.then(data => console.log('Download ended. Bytes downloaded:', data.size))
.catch(error => console.error('Error during fetch()', error))

// Here's an example of how to abort request once fetch() starts
function startAbortSimulation(responseReader) {
  // abort fetch() after 50ms
  setTimeout(function() {
    console.log('aborting fetch()...');
    .then(function() {
      console.log('fetch() aborted');

// ReadableStream constructor requires custom implementation of start() method
function ReadableStreamConfig(reader) {
  return {
    start(controller) {
      function read() {{done,value}) => {
          if (done) {

Listview Scroll to the end of the list after updating the list

To get this in a ListFragment:


Added this answer because if someone do a google search for same problem with ListFragment he just finds this..


Convert line endings

Doing this with POSIX is tricky:

  • POSIX Sed does not support \r or \15. Even if it did, the in place option -i is not POSIX

  • POSIX Awk does support \r and \15, however the -i inplace option is not POSIX

  • d2u and dos2unix are not POSIX utilities, but ex is

  • POSIX ex does not support \r, \15, \n or \12

To remove carriage returns:

awk 'BEGIN{RS="^$";ORS="";getline;gsub("\r","");print>ARGV[1]}' file

To add carriage returns:

awk 'BEGIN{RS="^$";ORS="";getline;gsub("\n","\r&");print>ARGV[1]}' file

Stacking DIVs on top of each other?

Position the outer div however you want, then position the inner divs using absolute. They'll all stack up.

.inner {_x000D_
  position: absolute;_x000D_
<div class="outer">_x000D_
   <div class="inner">1</div>_x000D_
   <div class="inner">2</div>_x000D_
   <div class="inner">3</div>_x000D_
   <div class="inner">4</div>_x000D_

How to disable the ability to select in a DataGridView?

I liked user4101525's answer best in theory but it doesn't actually work. Selection is not an overlay so you see whatever is under the control

Ramgy Borja's answer doesn't deal with the fact that default style is not actually a color at all so applying it doesn't help. This handles the default style and works if applying your own colors (which may be what edhubbell refers to as nasty results)

dgv.RowsDefaultCellStyle.SelectionBackColor = dgv.RowsDefaultCellStyle.BackColor.IsEmpty ? System.Drawing.Color.White : dgv.RowsDefaultCellStyle.BackColor;
dgv.RowsDefaultCellStyle.SelectionForeColor = dgv.RowsDefaultCellStyle.ForeColor.IsEmpty ? System.Drawing.Color.Black : dgv.RowsDefaultCellStyle.ForeColor;

How do I print the elements of a C++ vector in GDB?

With GCC 4.1.2, to print the whole of a std::vector<int> called myVector, do the following:

print *(myVector._M_impl._M_start)@myVector.size()

To print only the first N elements, do:

print *(myVector._M_impl._M_start)@N


This is probably heavily dependent on your compiler version, but for GCC 4.1.2, the pointer to the internal array is:


And the GDB command to print N elements of an array starting at pointer P is:

print P@N

Or, in a short form (for a standard .gdbinit):

p P@N

What is the difference between Bootstrap .container and .container-fluid classes?

Updated 2019

The basic difference is that container is scales responsively, while container-fluid is always width:100%. Therefore in the root CSS definitions, they appear the same, but if you look further you'll see that .container is bound to media queries.

Bootstrap 4

The container has 5 widths...

.container {
  width: 100%;

@media (min-width: 576px) {
  .container {
    max-width: 540px;

@media (min-width: 768px) {
  .container {
    max-width: 720px;

@media (min-width: 992px) {
  .container {
    max-width: 960px;

@media (min-width: 1200px) {
  .container {
    max-width: 1140px;

Bootstrap 3

The container has 4 sizes. Full width on xs screens, and then it's width varies based on the following media queries..

    @media (min-width: 1200px) {
        .container {
            width: 1170px;
    @media (min-width: 992px) {
        .container {
            width: 970px;
    @media (min-width: 768px) {
        .container {
            width: 750px;

container vs. container-fluid demo

What online brokers offer APIs?

Only related with currency trading (Forex), but many Forex brokers are offering MetaTrader which let you code in MQL. The main problem with it (aside that it's limited to Forex) is that you've to code in MQL which might not be your preferred language.

Revert a jQuery draggable object back to its original container on out event of droppable

$(function() {
        revert : function(event, ui) {
            // on older version of jQuery use "draggable"
            // $(this).data("draggable")
            // on 2.x versions of jQuery use "ui-draggable"
            // $(this).data("ui-draggable")
            $(this).data("uiDraggable").originalPosition = {
                top : 0,
                left : 0
            // return boolean
            return !event;
            // that evaluate like this:
            // return event !== false ? false : true;

Angular 2: How to call a function after get a response from subscribe

You can add a callback function to your list of get_category(...) parameters.


 get_categories(number, callback){ url, body, {headers: headers, withCredentials:true})
      response => { = response.json();

      }, error => {


And then you can just call get_category(...) like this:

this.get_category(1, name_of_function);

MySQL default datetime through phpmyadmin

I don't think you can achieve that with mysql date. You have to use timestamp or try this approach..

FOR EACH ROW SET NEW.dateColumn = IFNULL(NEW.dateColumn, NOW());

How to download Google Play Services in an Android emulator?

If your emulator x86 this method works your me.

Download and install And select nano pack

More info

enter image description here

enter image description here

Calling stored procedure with return value

You need to add return parameter to the command:

using (SqlConnection conn = new SqlConnection(getConnectionString()))
using (SqlCommand cmd = conn.CreateCommand())
    cmd.CommandText = parameterStatement.getQuery();
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.Parameters.AddWithValue("SeqName", "SeqNameValue");

    var returnParameter = cmd.Parameters.Add("@ReturnVal", SqlDbType.Int);
    returnParameter.Direction = ParameterDirection.ReturnValue;

    var result = returnParameter.Value;

Failed to create provisioning profile

preparing debugger support

Profiling your Phone takes a few minutes. . . watch the status bar on the top to be sure that your phone is being profiled on the top.

Next, be sure you choose YOUR PHONE as the target, not iPhone 7 or iPhone 8... your exact phone. This is done by choosing: Product > Destination > (pick your phone)

Your phone will only show up after it's been plugged in, turned on, and left running for a few minutes while Xcode creates a profile. destination

Finding the last index of an array

Use Array.GetUpperBound(0). Array.Length contains the number of items in the array, so reading Length -1 only works on the assumption that the array is zero based.

Checking if date is weekend PHP

If you have PHP >= 5.1:

function isWeekend($date) {
    return (date('N', strtotime($date)) >= 6);


function isWeekend($date) {
    $weekDay = date('w', strtotime($date));
    return ($weekDay == 0 || $weekDay == 6);

How to parse/read a YAML file into a Python object?


add_path_resolver(tag, path, kind) adds a path-based implicit tag resolver. A path is a list of keys that form a path to a node in the representation graph. Paths elements can be string values, integers, or None. The kind of a node can be str, list, dict, or None.

#!/usr/bin/env python
import yaml

class Person(yaml.YAMLObject):
  yaml_tag = '!person'

  def __init__(self, name): = name

yaml.add_path_resolver('!person', ['Person'], dict)

data = yaml.load("""
  name: XYZ

print data
# {'Person': <__main__.Person object at 0x7f2b251ceb10>}

print data['Person'].name

How to read the last row with SQL Server

You'll need some sort of uniquely identifying column in your table, like an auto-filling primary key or a datetime column (preferably the primary key). Then you can do this:

SELECT * FROM table_name ORDER BY unique_column DESC LIMIT 1

The ORDER BY column tells it to rearange the results according to that column's data, and the DESC tells it to reverse the results (thus putting the last one first). After that, the LIMIT 1 tells it to only pass back one row.

Filtering lists using LINQ

This LINQ below will generate the SQL for a left outer join and then take all of the results that don't find a match in your exclusion list.

List<Person> filteredResults =from p in people
        join e in exclusions on p.compositeKey equals e.compositeKey into temp
        from t in temp.DefaultIfEmpty()
        where t.compositeKey == null
        select p

let me know if it works!

Setting maxlength of textbox with JavaScript or jQuery

set the attribute, not a property

$("#ms_num").attr("maxlength", 6);

Datetime format Issue: String was not recognized as a valid DateTime

Below code worked for me:

string _stDate = Convert.ToDateTime(DateTime.Today.AddMonths(-12)).ToString("MM/dd/yyyy");
String format ="MM/dd/yyyy";
IFormatProvider culture = new System.Globalization.CultureInfo("fr-FR", true);
DateTime _Startdate = DateTime.ParseExact(_stDate, format, culture);

PHPExcel - set cell type before writing a value in it

When the text is a number with leading zeros, then do: (Cuando el texto es un número que empieza por ceros, hacer)

$objPHPExcel->getActiveSheet()->setCellValueExplicit('A1', $val,PHPExcel_Cell_DataType::TYPE_STRING);

Where is the .NET Framework 4.5 directory?

EDIT: This answer was correct until mid-2013, but you may have a more recent version since the big msbuild change. See the answer from Jonny Leeds for more details.

The version under C:\Windows\Microsoft.NET\Framework\v4.0.30319 actually is .NET 4.5. It's a little odd, but certainly mscorlib there contains AsyncTaskMethodBuilder etc which are used for async.

.NET 4.5 effectively overwrites .NET 4.

TypeError: 'bool' object is not callable

You do cls.isFilled = True. That overwrites the method called isFilled and replaces it with the value True. That method is now gone and you can't call it anymore. So when you try to call it again you get an error, since it's not there anymore.

The solution is use a different name for the variable than you do for the method.

How to copy commits from one branch to another?

git cherry-pick : Apply the changes introduced by some existing commits

Assume we have branch A with (X, Y, Z) commits. We need to add these commits to branch B. We are going to use the cherry-pick operations.

When we use cherry-pick, we should add commits on branch B in the same chronological order that the commits appear in Branch A.

cherry-pick does support a range of commits, but if you have merge commits in that range, it gets really complicated

git checkout B
git cherry-pick SHA-COMMIT-X
git cherry-pick SHA-COMMIT-Y
git cherry-pick SHA-COMMIT-Z

Example of workflow :

enter image description here

We can use cherry-pick with options

-e or --edit : With this option, git cherry-pick will let you edit the commit message prior to committing.

-n or --no-commit : Usually the command automatically creates a sequence of commits. This flag applies the changes necessary to cherry-pick each named commit to your working tree and the index, without making any commit. In addition, when this option is used, your index does not have to match the HEAD commit. The cherry-pick is done against the beginning state of your index.

Here an interesting article concerning cherry-pick.

isolating a sub-string in a string before a symbol in SQL Server 2008

DECLARE @dd VARCHAR(200) = 'Net Operating Loss - 2007';

SELECT SUBSTRING(@dd, 1, CHARINDEX('-', @dd) -1) F1,
       SUBSTRING(@dd, CHARINDEX('-', @dd) +1, LEN(@dd)) F2

Unable to create a constant value of type Only primitive types or enumeration types are supported in this context

Just add AsEnumerable() andToList() , so it looks like this

    .Where(x => x.userId == userId)
    .Join(db.Person, x => x.personId, y => y.personId, (x, y).ToList().AsEnumerable()


Python name 'os' is not defined

Just add:

import os

in the beginning, before:

from settings import PROJECT_ROOT

This will import the python's module os, which apparently is used later in the code of your module without being imported.

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '1922-1' for key 'IDX_STOCK_PRODUCT'

your column value is already in database table it means your table column is Unique you should change your value and try again

Git keeps asking me for my ssh key passphrase

Another possible solution that is not mentioned above is to check your remote with the following command:

git remote -v

If the remote does not start with git but starts with https you might want to change it to git by following the example below.

git remote -v // origin is
git remote set-url origin [email protected]:user/myrepo.git
git remote -v // check if remote is changed

Show space, tab, CRLF characters in editor of Visual Studio

Display white space characters

Menu: You can toggle the visibility of the white space characters from the menu: Edit > Advanced > View White Space.

Button: If you want to add the button to a toolbar, it is called Toggle Visual Space in the command category "Edit".
The actual command name is: Edit.ViewWhiteSpace.

Keyboard Shortcut: In Visual Studio 2015, 2017 and 2019 the default keyboard shortcut still is CTRL+R, CTRL+W
Type one after the other.
All default shortcuts

End-of-line characters

Extension: There is a minimal extension adding the displaying of end-of-line characters (LF and CR) to the visual white space mode, as you would expect. Additionally it supplies buttons and short-cuts to modify all line-endings in a document, or a selection.
VisualStudio gallery: End of the Line

Note: Since Visual Studio 2017 there is no option in the File-menu called Advanced Save Options. Changing the encoding and line-endings for a file can be done using Save File As ... and clicking the down-arrow on the right side of the save-button. This shows the option Save with Encoding. You'll be asked permission to overwrite the current file.

Python conversion from binary string to hexadecimal

Converting Binary into hex without ignoring leading zeros:

You could use the format() built-in function like this:

"{0:0>4X}".format(int("0000010010001101", 2))

R: invalid multibyte string

If you want an R solution, here's a small convenience function I sometimes use to find where the offending (multiByte) character is lurking. Note that it is the next character to what gets printed. This works because print will work fine, but substr throws an error when multibyte characters are present.

find_offending_character <- function(x, maxStringLength=256){  
  for (c in 1:maxStringLength){
    offendingChar <- substr(x,c,c)
    #print(offendingChar) #uncomment if you want the indiv characters printed
    #the next character is the offending multibyte Character

string_vector <- c("test", "Se\x96ora", "works fine")

lapply(string_vector, find_offending_character)

I fix that character and run this again. Hope that helps someone who encounters the invalid multibyte string error.

How to add to the end of lines containing a pattern with sed or awk?

This should work for you

sed -e 's_^all: .*_& anotherthing_'

Using s command (substitute) you can search for a line which satisfies a regular expression. In the command above, & stands for the matched string.

ADB - Android - Getting the name of the current activity

I prefer parsing results of dumpsys window windows over dumpsys activity

adb shell dumpsys window windows | grep -E 'mCurrentFocus|mFocusedApp'

Keyguard or Recent tasks list used to not show up as Activities but you were able to see them with mCurrentFocus. I have explained why in this answer.

Retrieve column names from java.sql.ResultSet

This question is old and so are the correct previous answers. But what I was looking for when I found this topic was something like this solution. Hopefully it helps someone.

// Loading required libraries    
import java.util.*;
import java.sql.*;

public class MySQLExample {
  public void run(String sql) {
    // JDBC driver name and database URL
    String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    String DB_URL = "jdbc:mysql://localhost/demo";

    // Database credentials
    String USER = "someuser"; // Fake of course.
    String PASS = "somepass"; // This too!

    Statement stmt = null;
    ResultSet rs = null;
    Connection conn = null;
    Vector<String> columnNames = new Vector<String>();

    try {
      // Register JDBC driver

      // Open a connection
      conn = DriverManager.getConnection(DB_URL, USER, PASS);

      // Execute SQL query
      stmt = conn.createStatement();
      rs = stmt.executeQuery(sql);
      if (rs != null) {
        ResultSetMetaData columns = rs.getMetaData();
        int i = 0;
        while (i < columns.getColumnCount()) {
          System.out.print(columns.getColumnName(i) + "\t");

        while ( {
          for (i = 0; i < columnNames.size(); i++) {
                + "\t");


    } catch (Exception e) {
      System.out.println("Exception: " + e.toString());

    finally {
      try {
        if (rs != null) {
        if (stmt != null) {
        if (conn != null) {
      } catch (Exception mysqlEx) {


Reading HTML content from a UIWebView

you should try this:


Now() function with time trim


That's the best I've found. If you have the date as a string already you can just do:

DateValue("12/04/2012 04:56:15")



Hope this helps someone...

Using an Alias in a WHERE clause

This is not possible directly, because chronologically, WHERE happens before SELECT, which always is the last step in the execution chain.

You can do a sub-select and filter on it:

  SELECT A.identifier
    , TO_NUMBER(DECODE( A.month_no
      , 1, 200803 
      , 2, 200804 
      , 3, 200805 
      , 4, 200806 
      , 5, 200807 
      , 6, 200808 
      , 7, 200809 
      , 8, 200810 
      , 9, 200811 
      , 10, 200812 
      , 11, 200701 
      , 12, 200702
      , NULL)) as MONTH_NO
    , TO_NUMBER(TO_CHAR(B.last_update_date, 'YYYYMM')) as UPD_DATE
  FROM table_a A
    , table_b B
  WHERE A.identifier = B.identifier
) AS inner_table

Interesting bit of info moved up from the comments:

There should be no performance hit. Oracle does not need to materialize inner queries before applying outer conditions -- Oracle will consider transforming this query internally and push the predicate down into the inner query and will do so if it is cost effective. – Justin Cave