Programs & Examples On #Maven war plugin

The WAR Plugin is responsible for collecting all artifact dependencies, classes and resources of the web application and packaging them into a web application archive.

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

In my case, the error was valid and it was due to using try with resource

 try (ConfigurableApplicationContext cxt = new ClassPathXmlApplicationContext(
                    "classpath:application-main-config.xml")) {..
}

It auto closes the stream which should not happen if I want to reuse this context in other beans.

java.lang.ClassNotFoundException: org.apache.jsp.index_jsp

This was caused because of something like this in my case:

<jsp-config>
    <jsp-property-group>
        <url-pattern>*.jsp</url-pattern>
        <include-prelude>/headerfooter/header.jsp</include-prelude>
        <include-coda>/headerfooter/footer.jsp</include-coda>
    </jsp-property-group>
</jsp-config>

The problem was actually I did not have header.jsp in my project. However the error message was still saying index_jsp was not found.

Dynamic Web Module 3.0 -- 3.1

In a specific case the issue is due to the maven-archetype-webapp which is released for a dynamic webapp, faceted to the ver.2.5 (see the produced web.xml and the related xsd) and it's related to eclipse. When you try to change the project facet to dynamic webapp > 2.5 the src folder structure will syntactically change (the 2.5 is different from 3.1), but not fisically.

This is why you will face in a null pointer exception if you apply to the changes.

To solve it you have to set from the project facets configuration the Default configuration. Apply the changes, then going into the Java Build Path you have to remove the /src folder and create the /src/main/java folder at least (it's also required /src/main/resources and /src/test/java to be compliant) re-change into the required configuration you desire (3.0, 3.1) and then do apply.

A required class was missing while executing org.apache.maven.plugins:maven-war-plugin:2.1.1:war

You should add maven-resources-plugin in your pom.xml file. Deleting ~/.m2/repository does not work always.

        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-resources-plugin</artifactId>
                <version>2.4</version>
            </plugin>
        </plugins>

Now build your project again. It should be successful!

Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile)

check the property endorsed.dir tag in your pom.xml.
I also had this problem and I fixed by modifying the property.

Example:

<endorsed.dir>${project.build.directory}/endorsed</endorsed.dir>  

Why is Maven downloading the maven-metadata.xml every time?

Maven does this because your dependency is in a SNAPSHOT version and maven has no way to detect any changes made to that snapshot version in the repository. Release your artifact and change the version in pom.xml to that version and maven will no longer fetch the metadata file.

How to make war file in Eclipse

File -> Export -> Web -> WAR file

OR in Kepler follow as shown below :

enter image description here

How to detect Esc Key Press in React and how to handle it

You'll want to listen for escape's keyCode (27) from the React SyntheticKeyBoardEvent onKeyDown:

const EscapeListen = React.createClass({
  handleKeyDown: function(e) {
    if (e.keyCode === 27) {
      console.log('You pressed the escape key!')
    }
  },

  render: function() {
    return (
      <input type='text'
             onKeyDown={this.handleKeyDown} />
    )
  }
})

Brad Colthurst's CodePen posted in the question's comments is helpful for finding key codes for other keys.

How to align text below an image in CSS?

Best way is to wrap the Image and Paragraph text with a DIV and assign a class.

Example:

<div class="image1">
    <div class="imgWrapper">
        <img src="images/img1.png" width="250" height="444" alt="Screen 1"/>
        <p>It's my first Image</p>
    </div>
    ...
    ...
    ...
    ...
</div>

Bind service to activity in Android

This is a biased answer, but I wrote a library that may simplify the usage of Android Services, if they run locally in the same process as the app: https://github.com/germnix/acacia

Basically you define an interface annotated with @Service and its implementing class, and the library creates and binds the service, handles the connection and the background worker thread:

@Service(ServiceImpl.class)
public interface MyService {
    void doProcessing(Foo aComplexParam);
}

public class ServiceImpl implements MyService {
    // your implementation
}

MyService service = Acacia.createService(context, MyService.class);
service.doProcessing(foo);

<application
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme">
    ...
    <service android:name="com.gmr.acacia.AcaciaService"/>
    ...
</application>

You can get an instance of the associated android.app.Service to hide/show persistent notifications, use your own android.app.Service and manually handle threading if you wish.

How to get the body's content of an iframe in Javascript?

I think placing text inbetween the tags is reserved for browsers that cant handle iframes i.e...

<iframe src ="html_intro.asp" width="100%" height="300">
  <p>Your browser does not support iframes.</p>
</iframe>

You use the 'src' attribute to set the source of the iframes html...

Hope that helps :)

get list of pandas dataframe columns based on data type

If after 6 years you still have the issue, this should solve it :)

cols = [c for c in df.columns if df[c].dtype in ['object', 'datetime64[ns]']]

Set max-height on inner div so scroll bars appear, but not on parent div

This would work just fine, set the height to desired pixel

#inner-right{
            height: 100px;
            overflow:auto;
            }

HttpListener Access Denied

httpListener.Prefixes.Add("http://*:4444/");

you use "*" so you execute following cmd as admin

netsh http add urlacl url=http://*:4444/ user=username

no use +, must use *, because you spec *:4444~.

https://msdn.microsoft.com/en-us/library/system.net.httplistener.aspx

How to return rows from left table not found in right table?

I also like to use NOT EXISTS. When it comes to performance if index correctly it should perform the same as a LEFT JOIN or better. Plus its easier to read.

SELECT Column1
FROM TableA a
WHERE NOT EXISTS ( SELECT Column1
                   FROM Tableb b
                   WHERE a.Column1 = b.Column1
                 )

Adding Apostrophe in every field in particular column for excel

The way I'd do this is:

  • In Cell L2, enter the formula ="'"&K2
  • Use the fill handle or Ctrl+D to fill it down to the length of Column K's values.
  • Select the whole of Column L's values and copy them to the clipboard
  • Select the same range in Column K, right-click to select 'Paste Special' and choose 'Values'

How do I find a list of Homebrew's installable packages?

From the man page:

search, -S text|/text/
Perform a substring search of formula names for text. If text is surrounded with slashes,
then it is interpreted as a regular expression. If no search term is given,
all available formula are displayed.

For your purposes, brew search will suffice.

typescript: error TS2693: 'Promise' only refers to a type, but is being used as a value here

Solved by changing the target in compilerOptions.

{
"compilerOptions": {
    "module": "es2015",
    "target": "es2015",
    "lib": [
        "es2016",
        "dom"
    ],
    "moduleResolution": "node",
    "noImplicitAny": false,
    "sourceMap": false,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "outDir": "./public/js/app"
},
"exclude": [
    "node_modules",
    "public/js",
    "assets/app/polyfills.ts"
],
"angularCompilerOptions": {
    "skipMetadataEmit": true
}
}

Body of Http.DELETE request in Angular2

The http.delete(url, options) does accept a body. You just need to put it within the options object.

http.delete('/api/something', new RequestOptions({
   headers: headers,
   body: anyObject
}))

Reference options interface: https://angular.io/api/http/RequestOptions

UPDATE:

The above snippet only works for Angular 2.x, 4.x and 5.x.

For versions 6.x onwards, Angular offers 15 different overloads. Check all overloads here: https://angular.io/api/common/http/HttpClient#delete

Usage sample:

const options = {
  headers: new HttpHeaders({
    'Content-Type': 'application/json',
  }),
  body: {
    id: 1,
    name: 'test',
  },
};

this.httpClient
  .delete('http://localhost:8080/something', options)
  .subscribe((s) => {
    console.log(s);
  });

How to Compare two Arrays are Equal using Javascript?

Use lodash. In ES6 syntax:

import isEqual from 'lodash/isEqual';
let equal = isEqual([1,2], [1,2]);  // true

Or previous js versions:

var isEqual = require('lodash/isEqual');
var equal = isEqual([1,2], [1,2]);  // true

Git push/clone to new server

There are many ways to move repositories around, git bundle is a nice way if you have insufficient network availability. Since a Git repository is really just a directory full of files, you can "clone" a repository by making a copy of the .git directory in whatever way suits you best.

The most efficient way is to use an external repository somewhere (use GitHub or set up Gitosis), and then git push.

How to work offline with TFS

See this reference for information on how to bind/unbind your solution or project from source control. NOTE: this doesn't apply if you are using GIT and may not apply to versions later than VS2008.

Quoting from the reference:

To disconnect a solution or project from source control

  1. In Visual Studio, open Solution Explorer and select the item(s) to disconnect.

  2. On the File menu, click Source Control, then Change Source Control.

  3. In the Change Source Control dialog box, click Disconnect.

  4. Click OK.

How to open a new window on form submit

For a similar effect to form's target attribute, you can also use the formtarget attribute of input[type="submit]" or button[type="submit"].

From MDN:

...this attribute is a name or keyword indicating where to display the response that is received after submitting the form. This is a name of, or keyword for, a browsing context (for example, tab, window, or inline frame). If this attribute is specified, it overrides the target attribute of the elements's form owner. The following keywords have special meanings:

  • _self: Load the response into the same browsing context as the current one. This value is the default if the attribute is not specified.
  • _blank: Load the response into a new unnamed browsing context.
  • _parent: Load the response into the parent browsing context of the current one. If there is no parent, this option behaves the same way as _self.
  • _top: Load the response into the top-level browsing context (that is, the browsing context that is an ancestor of the current one, and has no parent). If there is no parent, this option behaves the same way as _self.

Spring Boot java.lang.NoClassDefFoundError: javax/servlet/Filter

providedRuntime("org.springframework.boot:spring-boot-starter-tomcat")

This should be

compile("org.springframework.boot:spring-boot-starter-tomcat")

Blocking device rotation on mobile web pages

Simple Javascript code to make mobile browser display either in portrait or landscape..

(Even though you have to enter html code twice in the two DIVs (one for each mode), arguably this will load faster than using javascript to change the stylesheet...

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Mobile Device</title>
<script type="text/javascript">
// Detect whether device supports orientationchange event, otherwise fall back to
// the resize event.
var supportsOrientationChange = "onorientationchange" in window,
    orientationEvent = supportsOrientationChange ? "orientationchange" : "resize";

window.addEventListener(orientationEvent, function() {
    if(window.orientation==0)
    {
      document.getElementById('portrait').style.display = '';
      document.getElementById('landscape').style.display = 'none';
    }
    else if(window.orientation==90)
    {
      document.getElementById('portrait').style.display = 'none';
      document.getElementById('landscape').style.display = '';
    }
}, false);
</script>
<meta name="HandheldFriendly" content="true" />
<meta name="viewport" content="width=device-width, height=device-height, user-scalable=no" />
</head>
<body>
<div id="portrait" style="width:100%;height:100%;font-size:20px;">Portrait</div>
<div id="landscape" style="width:100%;height:100%;font-size:20px;">Landscape</div>

<script type="text/javascript">
if(window.orientation==0)
{
  document.getElementById('portrait').style.display = '';
  document.getElementById('landscape').style.display = 'none';
}
else if(window.orientation==90)
{
  document.getElementById('portrait').style.display = 'none';
  document.getElementById('landscape').style.display = '';
}
</script>
</body>
</html>

Tested and works on Android HTC Sense and Apple iPad.

Working with dictionaries/lists in R

Yes, the list type is a good approximation. You can use names() on your list to set and retrieve the 'keys':

> foo <- vector(mode="list", length=3)
> names(foo) <- c("tic", "tac", "toe")
> foo[[1]] <- 12; foo[[2]] <- 22; foo[[3]] <- 33
> foo
$tic
[1] 12

$tac
[1] 22

$toe
[1] 33

> names(foo)
[1] "tic" "tac" "toe"
> 

React onClick and preventDefault() link refresh/redirect?

React events are actually Synthetic Events, not Native Events. As it is written here:

Event delegation: React doesn't actually attach event handlers to the nodes themselves. When React starts up, it starts listening for all events at the top level using a single event listener. When a component is mounted or unmounted, the event handlers are simply added or removed from an internal mapping. When an event occurs, React knows how to dispatch it using this mapping. When there are no event handlers left in the mapping, React's event handlers are simple no-ops.

Try to use Use Event.stopImmediatePropagation:

upvote: (e) ->
  e.stopPropagation();
  e.nativeEvent.stopImmediatePropagation();

svn: E155004: ..(path of resource).. is already locked

  1. Downlaod and copy sqlite.exe to .svn's parent directory
  2. Open shell in this directory
  3. Query to find locks in corresponding tables => in wc_lock* table (the table name is something like this)
  4. Delete the locked items in above table by sqlite query

just this steps helped me to resolve:

svn: E155004: Working copy 'resourceAddress' locked

Compare 2 arrays which returns difference

This should work with unsorted arrays, double values and different orders and length, while giving you the filtered values form array1, array2, or both.

function arrayDiff(arr1, arr2) {
    var diff = {};

    diff.arr1 = arr1.filter(function(value) {
        if (arr2.indexOf(value) === -1) {
            return value;
        }
    });

    diff.arr2 = arr2.filter(function(value) {
        if (arr1.indexOf(value) === -1) {
            return value;
        }
    });

    diff.concat = diff.arr1.concat(diff.arr2);

    return diff;
};

var firstArray = [1,2,3,4];
var secondArray = [4,6,1,4];

console.log( arrayDiff(firstArray, secondArray) );
console.log( arrayDiff(firstArray, secondArray).arr1 );
// => [ 2, 3 ]
console.log( arrayDiff(firstArray, secondArray).concat );
// => [ 2, 3, 6 ]

Utility of HTTP header "Content-Type: application/force-download" for mobile?

application/force-download is not a standard MIME type. It's a hack supported by some browsers, added fairly recently.

Your question doesn't really make any sense. It's like asking why Internet Explorer 4 doesn't support the latest CSS 3 functionality.

Redis connection to 127.0.0.1:6379 failed - connect ECONNREFUSED

for Windows users, you can use chocolatey to install Redis

choco install redis-64

then run server from

C:\ProgramData\chocolatey\lib\redis-64\redis-server.exe

How to add parameters to an external data query in Excel which can't be displayed graphically?

If you have Excel 2007 you can write VBA to alter the connections (i.e. the external data queries) in a workbook and update the CommandText property. If you simply add ? where you want a parameter, then next time you refresh the data it'll prompt for the values for the connections! magic. When you look at the properties of the Connection the Parameters button will now be active and useable as normal.

E.g. I'd write a macro, step through it in the debugger, and make it set the CommandText appropriately. Once you've done this you can remove the macro - it's just a means to update the query.

Sub UpdateQuery
    Dim cn As WorkbookConnection
    Dim odbcCn As ODBCConnection, oledbCn As OLEDBConnection
    For Each cn In ThisWorkbook.Connections
        If cn.Type = xlConnectionTypeODBC Then
            Set odbcCn = cn.ODBCConnection

            ' If you do have multiple connections you would want to modify  
            ' the line below each time you run through the loop.
            odbcCn.CommandText = "select blah from someTable where blah like ?"

        ElseIf cn.Type = xlConnectionTypeOLEDB Then
            Set oledbCn = cn.OLEDBConnection
            oledbCn.CommandText = "select blah from someTable where blah like ?" 
        End If
    Next
End Sub

How to get detailed list of connections to database in sql server 2005?

As @Hutch pointed out, one of the major limitations of sp_who2 is that it does not take any parameters so you cannot sort or filter it by default. You can save the results into a temp table, but then the you have to declare all the types ahead of time (and remember to DROP TABLE).

Instead, you can just go directly to the source on master.dbo.sysprocesses

I've constructed this to output almost exactly the same thing that sp_who2 generates, except that you can easily add ORDER BY and WHERE clauses to get meaningful output.

SELECT  spid,
        sp.[status],
        loginame [Login],
        hostname, 
        blocked BlkBy,
        sd.name DBName, 
        cmd Command,
        cpu CPUTime,
        physical_io DiskIO,
        last_batch LastBatch,
        [program_name] ProgramName   
FROM master.dbo.sysprocesses sp 
JOIN master.dbo.sysdatabases sd ON sp.dbid = sd.dbid
ORDER BY spid 

Vertically and horizontally centering text in circle in CSS (like iphone notification badge)

Interesting question! While there are plenty of guides on horizontally and vertically centering a div, an authoritative treatment of the subject where the centered div is of an unpredetermined width is conspicuously absent.

Let's apply some basic constraints:

  • No Javascript
  • No mangling of the display property to table-cell, which is of questionable support status

Given this, my entry into the fray is the use of the inline-block display property to horizontally center the span within an absolutely positioned div of predetermined height, vertically centered within the parent container in the traditional top: 50%; margin-top: -123px fashion.

Markup: div > div > span

CSS:

body > div { position: relative; height: XYZ; width: XYZ; }
div > div { 
  position: absolute;
  top: 50%;
  height: 30px;
  margin-top: -15px; 
  text-align: center;}
div > span { display: inline-block; }

Source: http://jsfiddle.net/38EFb/


An alternate solution that doesn't require extraneous markups but that very likely produces more problems than it solves is to use the line-height property. Don't do this. But it is included here as an academic note: http://jsfiddle.net/gucwW/

Webpack.config how to just copy the index.html to the dist folder

You could use the CopyWebpackPlugin. It's working just like this:

module.exports = {
  plugins: [
    new CopyWebpackPlugin([{
      from: './*.html'
    }])
  ]
}

PHP Array to CSV

Try using;

PHP_EOL

To terminate each new line in your CSV output.

I'm assuming that the text is delimiting, but isn't moving to the next row?

That's a PHP constant. It will determine the correct end of line you need.

Windows, for example, uses "\r\n". I wracked my brains with that one when my output wasn't breaking to a new line.

how to write unified new line in PHP?

in_array multiple values

Intersect the targets with the haystack and make sure the intersection is precisely equal to the targets:

$haystack = array(...);

$target = array('foo', 'bar');

if(count(array_intersect($haystack, $target)) == count($target)){
    // all of $target is in $haystack
}

Note that you only need to verify the size of the resulting intersection is the same size as the array of target values to say that $haystack is a superset of $target.

To verify that at least one value in $target is also in $haystack, you can do this check:

 if(count(array_intersect($haystack, $target)) > 0){
     // at least one of $target is in $haystack
 }

How to submit http form using C#

I needed to have a button handler that created a form post to another application within the client's browser. I landed on this question but didn't see an answer that suited my scenario. This is what I came up with:

      protected void Button1_Click(object sender, EventArgs e)
        {

            var formPostText = @"<html><body><div>
<form method=""POST"" action=""OtherLogin.aspx"" name=""frm2Post"">
  <input type=""hidden"" name=""field1"" value=""" + TextBox1.Text + @""" /> 
  <input type=""hidden"" name=""field2"" value=""" + TextBox2.Text + @""" /> 
</form></div><script type=""text/javascript"">document.frm2Post.submit();</script></body></html>
";
            Response.Write(formPostText);
        }

Xcode 4 - "Archive" is greyed out?

I fixed this today...sort of. Although the archives still don't show up anywhere. But I got the Archive option back by going into Build Settings for the project and re-assigning my certs under "Code Signing Identity" for each build. They seemed to have gotten reset to something else when imported my 3.X project to 4.

I also used the instructions found here:

http://developer.apple.com/library/mac/#documentation/ToolsLanguages/Conceptual/Xcode4UserGuide/DistApps/DistApps.html#//apple_ref/doc/uid/TP40010215-CH11-DontLinkElementID_69

But I still can't get the actual archives to show up in Organizer (even though the files exist)

How can I see the specific value of the sql_mode?

You need to login to your mysql terminal first using mysql -u username -p password

Then use this:

SELECT @@sql_mode; or SELECT @@GLOBAL.sql_mode;

output will be like this:

STRICT_TRANS_TABLES,STRICT_ALL_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,TRADITIONAL,NO_AUTO_CREATE_USER,NO_ENGINE_SUB

You can also set sql mode by this:

SET GLOBAL sql_mode=TRADITIONAL;

How to use Bootstrap modal using the anchor tag for Register?

Here is a link to W3Schools that answers your question https://www.w3schools.com/bootstrap/bootstrap_ref_js_modal.asp

Note: For anchor tag elements, omit data-target, and use href="#modalID" instead:

I hope that helps

How to obtain the location of cacerts of the default java installation?

Under Linux, to find the location of $JAVA_HOME:

readlink -f /usr/bin/java | sed "s:bin/java::"

the cacerts are under lib/security/cacerts:

$(readlink -f /usr/bin/java | sed "s:bin/java::")lib/security/cacerts

Under mac OS X , to find $JAVA_HOME run:

/usr/libexec/java_home

the cacerts are under Home/lib/security/cacerts:

$(/usr/libexec/java_home)/lib/security/cacerts

UPDATE (OS X with JDK)

above code was tested on computer without JDK installed. With JDK installed, as pR0Ps said, it's at

$(/usr/libexec/java_home)/jre/lib/security/cacerts

POST request via RestTemplate in JSON

Why work harder than you have to? postForEntity accepts a simple Map object as input. The following works fine for me while writing tests for a given REST endpoint in Spring. I believe it's the simplest possible way of making a JSON POST request in Spring:

@Test
public void shouldLoginSuccessfully() {
  // 'restTemplate' below has been @Autowired prior to this
  Map map = new HashMap<String, String>();
  map.put("username", "bob123");
  map.put("password", "myP@ssw0rd");
  ResponseEntity<Void> resp = restTemplate.postForEntity(
      "http://localhost:8000/login",
      map,
      Void.class);
  assertThat(resp.getStatusCode()).isEqualTo(HttpStatus.OK);
}

R apply function with multiple parameters

Just pass var2 as an extra argument to one of the apply functions.

mylist <- list(a=1,b=2,c=3)
myfxn <- function(var1,var2){
  var1*var2
}
var2 <- 2

sapply(mylist,myfxn,var2=var2)

This passes the same var2 to every call of myfxn. If instead you want each call of myfxn to get the 1st/2nd/3rd/etc. element of both mylist and var2, then you're in mapply's domain.

Error after upgrading pip: cannot import name 'main'

Same thing happened to me on Pixelbook using the new LXC (strech). This solution is very similar to the accepted one, with one subtle difference, whiched fixed pip3 for me.

sudo python3 -m pip install --upgrade pip

That bumped the version, and now it works as expected.

I found it here ... Python.org: Ensure pip is up-to-date

How to hide elements without having them take space on the page?

Look, instead of using visibility: hidden; use display: none;. The first option will hide but still takes space and the second option will hide and doesn't take any space.

How can I push a specific commit to a remote, and not previous commits?

I believe you would have to "git revert" back to that commit and then push it. Or you could cherry-pick a commit into a new branch, and push that to the branch on the remote repository. Something like:

git branch onecommit
git checkout onecommit
git cherry-pick 7300a6130d9447e18a931e898b64eefedea19544 # From the other branch
git push origin {branch}

Enums in Javascript with ES6

you can also use es6-enum package (https://www.npmjs.com/package/es6-enum). It's very easy to use. See the example below:

import Enum from "es6-enum";
const Colors = Enum("red", "blue", "green");
Colors.red; // Symbol(red)

PDOException SQLSTATE[HY000] [2002] No such file or directory

If you are using Laravel Homestead, here is settings

(include Vagrant-Virtual Machine)

.bash-profile

alias vm="ssh [email protected] -p 2222"

database.php

    'mysql' => [
        'driver'    => 'mysql',
        'host'      => env('DB_HOST', '127.0.0.1'),
        'database'  => env('DB_DATABASE', 'homestead'),
        'username'  => env('DB_USERNAME', 'homestead'),
        'password'  => env('DB_PASSWORD', 'secret'),
        'charset'   => 'utf8',
        'collation' => 'utf8_unicode_ci',
        'prefix'    => '',
        'strict'    => false,
    ],

Terminal

vm

vagrant@homestead:~/Code/projectFolder  php artisan migrate:install

What is the best way to auto-generate INSERT statements for a SQL Server table?

Do you have data in a production database yet? If so, you could setup a period refresh of the data via DTS. We do ours weekly on the weekends and it is very nice to have clean, real data every week for our testing.

If you don't have production yet, then you should create a database that is they want you want it (fresh). Then, duplicate that database and use that newly created database as your test environment. When you want the clean version, simply duplicate your clean one again and Bob's your uncle.

How to create a signed APK file using Cordova command line interface?

Step1:

Go to cordova\platforms\android ant create a fille called ant.properties file with the keystore file info (this keystore can be generated from your favorite Android SDK, studio...):

key.store=C:\\yourpath\\Yourkeystore.keystore
key.alias=youralias

Step2:

Go to cordova path and execute:

cordova build android --release

Note: You will be prompted asking your keystore and key password

An YourApp-release.apk will appear in \cordova\platforms\android\ant-build

Difference between UTF-8 and UTF-16?

They're simply different schemes for representing Unicode characters.

Both are variable-length - UTF-16 uses 2 bytes for all characters in the basic multilingual plane (BMP) which contains most characters in common use.

UTF-8 uses between 1 and 3 bytes for characters in the BMP, up to 4 for characters in the current Unicode range of U+0000 to U+1FFFFF, and is extensible up to U+7FFFFFFF if that ever becomes necessary... but notably all ASCII characters are represented in a single byte each.

For the purposes of a message digest it won't matter which of these you pick, so long as everyone who tries to recreate the digest uses the same option.

See this page for more about UTF-8 and Unicode.

(Note that all Java characters are UTF-16 code points within the BMP; to represent characters above U+FFFF you need to use surrogate pairs in Java.)

JPA: JOIN in JPQL

Join on one-to-many relation in JPQL looks as follows:

select b.fname, b.lname from Users b JOIN b.groups c where c.groupName = :groupName 

When several properties are specified in select clause, result is returned as Object[]:

Object[] temp = (Object[]) em.createNamedQuery("...")
    .setParameter("groupName", groupName)
    .getSingleResult(); 
String fname = (String) temp[0];
String lname = (String) temp[1];

By the way, why your entities are named in plural form, it's confusing. If you want to have table names in plural, you may use @Table to specify the table name for the entity explicitly, so it doesn't interfere with reserved words:

@Entity @Table(name = "Users")     
public class User implements Serializable { ... } 

Go doing a GET request and building the Querystring

Using NewRequest just to create an URL is an overkill. Use the net/url package:

package main

import (
    "fmt"
    "net/url"
)

func main() {
    base, err := url.Parse("http://www.example.com")
    if err != nil {
        return
    }

    // Path params
    base.Path += "this will get automatically encoded"

    // Query params
    params := url.Values{}
    params.Add("q", "this will get encoded as well")
    base.RawQuery = params.Encode() 

    fmt.Printf("Encoded URL is %q\n", base.String())
}

Playground: https://play.golang.org/p/YCTvdluws-r

Exporting the values in List to excel

the one easy way to do it is to open Excel create sheet containing test data you want to export then say to excel save as xml open the xml see the xml format excel is expecting and generate it by head replacing the test data with export data

SpreadsheetML Markup Spec

@lan this is xml fo a simle execel file with one column value i genereted with office 2003 this format is for office 2003 and above

<?xml version="1.0"?>
<?mso-application progid="Excel.Sheet"?>
<Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:o="urn:schemas-microsoft-com:office:office"
 xmlns:x="urn:schemas-microsoft-com:office:excel"
 xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet"
 xmlns:html="http://www.w3.org/TR/REC-html40">
 <DocumentProperties xmlns="urn:schemas-microsoft-com:office:office">
  <Author>Dancho</Author>
  <LastAuthor>Dancho</LastAuthor>
  <Created>2010-02-05T10:15:54Z</Created>
  <Company>cc</Company>
  <Version>11.9999</Version>
 </DocumentProperties>
 <ExcelWorkbook xmlns="urn:schemas-microsoft-com:office:excel">
  <WindowHeight>13800</WindowHeight>
  <WindowWidth>24795</WindowWidth>
  <WindowTopX>480</WindowTopX>
  <WindowTopY>105</WindowTopY>
  <ProtectStructure>False</ProtectStructure>
  <ProtectWindows>False</ProtectWindows>
 </ExcelWorkbook>
 <Styles>
  <Style ss:ID="Default" ss:Name="Normal">
   <Alignment ss:Vertical="Bottom"/>
   <Borders/>
   <Font/>
   <Interior/>
   <NumberFormat/>
   <Protection/>
  </Style>
 </Styles>
 <Worksheet ss:Name="Sheet1">
  <Table ss:ExpandedColumnCount="1" ss:ExpandedRowCount="6" x:FullColumns="1"
   x:FullRows="1">
   <Row>
    <Cell><Data ss:Type="String">Value1</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value2</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value3</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value4</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value5</Data></Cell>
   </Row>
   <Row>
    <Cell><Data ss:Type="String">Value6</Data></Cell>
   </Row>
  </Table>
  <WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">
   <Selected/>
   <Panes>
    <Pane>
     <Number>3</Number>
     <ActiveRow>5</ActiveRow>
    </Pane>
   </Panes>
   <ProtectObjects>False</ProtectObjects>
   <ProtectScenarios>False</ProtectScenarios>
  </WorksheetOptions>
 </Worksheet>
 <Worksheet ss:Name="Sheet2">
  <WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">
   <ProtectObjects>False</ProtectObjects>
   <ProtectScenarios>False</ProtectScenarios>
  </WorksheetOptions>
 </Worksheet>
 <Worksheet ss:Name="Sheet3">
  <WorksheetOptions xmlns="urn:schemas-microsoft-com:office:excel">
   <ProtectObjects>False</ProtectObjects>
   <ProtectScenarios>False</ProtectScenarios>
  </WorksheetOptions>
 </Worksheet>
</Workbook>

Saving and loading objects and using pickle

As for your second problem:

 Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
 File "C:\Python31\lib\pickle.py", line
 1365, in load encoding=encoding,
 errors=errors).load() EOFError

After you have read the contents of the file, the file pointer will be at the end of the file - there will be no further data to read. You have to rewind the file so that it will be read from the beginning again:

file.seek(0)

What you usually want to do though, is to use a context manager to open the file and read data from it. This way, the file will be automatically closed after the block finishes executing, which will also help you organize your file operations into meaningful chunks.

Finally, cPickle is a faster implementation of the pickle module in C. So:

In [1]: import _pickle as cPickle

In [2]: d = {"a": 1, "b": 2}

In [4]: with open(r"someobject.pickle", "wb") as output_file:
   ...:     cPickle.dump(d, output_file)
   ...:

# pickle_file will be closed at this point, preventing your from accessing it any further

In [5]: with open(r"someobject.pickle", "rb") as input_file:
   ...:     e = cPickle.load(input_file)
   ...:

In [7]: print e
------> print(e)
{'a': 1, 'b': 2}

What are the best practices for SQLite on Android?

  • Use a Thread or AsyncTask for long-running operations (50ms+). Test your app to see where that is. Most operations (probably) don't require a thread, because most operations (probably) only involve a few rows. Use a thread for bulk operations.
  • Share one SQLiteDatabase instance for each DB on disk between threads and implement a counting system to keep track of open connections.

Are there any best practices for these scenarios?

Share a static field between all your classes. I used to keep a singleton around for that and other things that need to be shared. A counting scheme (generally using AtomicInteger) also should be used to make sure you never close the database early or leave it open.

My solution:

The old version I wrote is available at https://github.com/Taeluf/dev/tree/main/archived/databasemanager and is not maintained. If you want to understand my solution, look at the code and read my notes. My notes are usually pretty helpful.

  1. copy/paste the code into a new file named DatabaseManager. (or download it from github)
  2. extend DatabaseManager and implement onCreate and onUpgrade like you normally would. You can create multiple subclasses of the one DatabaseManager class in order to have different databases on disk.
  3. Instantiate your subclass and call getDb() to use the SQLiteDatabase class.
  4. Call close() for each subclass you instantiated

The code to copy/paste:

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;

import java.util.concurrent.ConcurrentHashMap;

/** Extend this class and use it as an SQLiteOpenHelper class
 *
 * DO NOT distribute, sell, or present this code as your own. 
 * for any distributing/selling, or whatever, see the info at the link below
 *
 * Distribution, attribution, legal stuff,
 * See https://github.com/JakarCo/databasemanager
 * 
 * If you ever need help with this code, contact me at [email protected] (or [email protected] )
 * 
 * Do not sell this. but use it as much as you want. There are no implied or express warranties with this code. 
 *
 * This is a simple database manager class which makes threading/synchronization super easy.
 *
 * Extend this class and use it like an SQLiteOpenHelper, but use it as follows:
 *  Instantiate this class once in each thread that uses the database. 
 *  Make sure to call {@link #close()} on every opened instance of this class
 *  If it is closed, then call {@link #open()} before using again.
 * 
 * Call {@link #getDb()} to get an instance of the underlying SQLiteDatabse class (which is synchronized)
 *
 * I also implement this system (well, it's very similar) in my <a href="http://androidslitelibrary.com">Android SQLite Libray</a> at http://androidslitelibrary.com
 * 
 *
 */
abstract public class DatabaseManager {
    
    /**See SQLiteOpenHelper documentation
    */
    abstract public void onCreate(SQLiteDatabase db);
    /**See SQLiteOpenHelper documentation
     */
    abstract public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion);
    /**Optional.
     * *
     */
    public void onOpen(SQLiteDatabase db){}
    /**Optional.
     * 
     */
    public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {}
    /**Optional
     * 
     */
    public void onConfigure(SQLiteDatabase db){}



    /** The SQLiteOpenHelper class is not actually used by your application.
     *
     */
    static private class DBSQLiteOpenHelper extends SQLiteOpenHelper {

        DatabaseManager databaseManager;
        private AtomicInteger counter = new AtomicInteger(0);

        public DBSQLiteOpenHelper(Context context, String name, int version, DatabaseManager databaseManager) {
            super(context, name, null, version);
            this.databaseManager = databaseManager;
        }

        public void addConnection(){
            counter.incrementAndGet();
        }
        public void removeConnection(){
            counter.decrementAndGet();
        }
        public int getCounter() {
            return counter.get();
        }
        @Override
        public void onCreate(SQLiteDatabase db) {
            databaseManager.onCreate(db);
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            databaseManager.onUpgrade(db, oldVersion, newVersion);
        }

        @Override
        public void onOpen(SQLiteDatabase db) {
            databaseManager.onOpen(db);
        }

        @Override
        public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            databaseManager.onDowngrade(db, oldVersion, newVersion);
        }

        @Override
        public void onConfigure(SQLiteDatabase db) {
            databaseManager.onConfigure(db);
        }
    }

    private static final ConcurrentHashMap<String,DBSQLiteOpenHelper> dbMap = new ConcurrentHashMap<String, DBSQLiteOpenHelper>();

    private static final Object lockObject = new Object();


    private DBSQLiteOpenHelper sqLiteOpenHelper;
    private SQLiteDatabase db;
    private Context context;

    /** Instantiate a new DB Helper. 
     * <br> SQLiteOpenHelpers are statically cached so they (and their internally cached SQLiteDatabases) will be reused for concurrency
     *
     * @param context Any {@link android.content.Context} belonging to your package.
     * @param name The database name. This may be anything you like. Adding a file extension is not required and any file extension you would like to use is fine.
     * @param version the database version.
     */
    public DatabaseManager(Context context, String name, int version) {
        String dbPath = context.getApplicationContext().getDatabasePath(name).getAbsolutePath();
        synchronized (lockObject) {
            sqLiteOpenHelper = dbMap.get(dbPath);
            if (sqLiteOpenHelper==null) {
                sqLiteOpenHelper = new DBSQLiteOpenHelper(context, name, version, this);
                dbMap.put(dbPath,sqLiteOpenHelper);
            }
            //SQLiteOpenHelper class caches the SQLiteDatabase, so this will be the same SQLiteDatabase object every time
            db = sqLiteOpenHelper.getWritableDatabase();
        }
        this.context = context.getApplicationContext();
    }
    /**Get the writable SQLiteDatabase
     */
    public SQLiteDatabase getDb(){
        return db;
    }

    /** Check if the underlying SQLiteDatabase is open
     *
     * @return whether the DB is open or not
     */
    public boolean isOpen(){
        return (db!=null&&db.isOpen());
    }


    /** Lowers the DB counter by 1 for any {@link DatabaseManager}s referencing the same DB on disk
     *  <br />If the new counter is 0, then the database will be closed.
     *  <br /><br />This needs to be called before application exit.
     * <br />If the counter is 0, then the underlying SQLiteDatabase is <b>null</b> until another DatabaseManager is instantiated or you call {@link #open()}
     *
     * @return true if the underlying {@link android.database.sqlite.SQLiteDatabase} is closed (counter is 0), and false otherwise (counter > 0)
     */
    public boolean close(){
        sqLiteOpenHelper.removeConnection();
        if (sqLiteOpenHelper.getCounter()==0){
            synchronized (lockObject){
                if (db.inTransaction())db.endTransaction();
                if (db.isOpen())db.close();
                db = null;
            }
            return true;
        }
        return false;
    }
    /** Increments the internal db counter by one and opens the db if needed
    *
    */
    public void open(){
        sqLiteOpenHelper.addConnection();
        if (db==null||!db.isOpen()){
                synchronized (lockObject){
                    db = sqLiteOpenHelper.getWritableDatabase();
                }
        } 
    }
}

How do I monitor all incoming http requests?

Configure Fiddler as a 'reverse proxy' on Windows

(for Mac, see the link in Partizano's comment below)

I know there's already an answer suggesting this, however I want to provide the explanation and instructions for this that Telerik should have provided, and also cover some of the 'gotchas', so here goes:

What does it mean to configure Fiddler as a 'reverse proxy'?

  • By default, Fiddler only monitors outgoing requests from the machine on which you're running Fiddler
  • To monitor incoming requests, you need to configure Fiddler to work as a 'reverse proxy'
  • What this means is that you need to set Fiddler up as a 'proxy' that will intercept incoming http requests that are sent to a specific port (8888) on the machine where you want to listen to the incoming requests. Fiddler will then forward those requests to the web server on the same machine by sending them to the usual port for http requests (usually port 80 or 443 for https). It's actually very quick and easy to do!
  • The standard way to set this up with Fiddler is to get Fiddler to intercept all request sent to Port '8888' (since this won't normally be used by anything else, although you could just as easily use another port)
  • You then need to use the registry editor to get Fiddler to forward any http requests that Fiddler receives on port 8888, so that they're forwarded to the standard http port (port 80, port 443 for an https request, or another custom port that your web server is set to listen on)

NOTE: For this to work, any request you want to intercept must be sent to port 8888

You do this by appending :8888 to your hostname, for example like this for an MVC route:

http://myhostname:8888/controller/action


Walkthrough

Ensure Fiddler can accept remote http requests on port 8888:

Run Fiddler as administrator Go to Tools > Fiddler Options > Connections, and ensure that 'Allow remote computers to connect' is checked, and 'Fiddler listens on port' is set to 8888:

enter image description here

Configure Fiddler to forward requests received on port 8888 to port 80

  • Close Fiddler
  • Start REGEDIT
  • Create a new DWORD named ReverseProxyForPort inside HKEY_CURRENT_USER\SOFTWARE\Microsoft\Fiddler2.
    • Now set the DWORD value to the local port you'd like to re-route inbound traffic to (generally port 80 for a standard HTTP server)
  • To do this, right-click the DWORD you created and select 'Modify'. Ensure 'Base' is set to 'Decimal' and enter '80' (or another port) as the 'Value data':

Ensure that port 8888 is opened on the firewall

  • You must ensure that port 8888 is open to external requests (it won't be by default if your server is firewall-protected)

That's it! Fiddler should now be set up as a reverse proxy, to intercept all requests from port 8888 (so that you can view them in Fiddler), and it will then forward them to your web server to actually be handled.

Test a request

  • Restart Fiddler
  • To test that Fiddler is intercepting external requests, open a browser on the same machine where you've set up Fiddler as a reverse proxy. Navigate your browser to http://127.0.0.1:8888
  • This tests making a basic request to to port 8888
  • You should see the request intercepted by Fiddler
  • Now you can test a request from another machine, for example by making a request from a browser on another machine like this (where 'remoteHostname' is a hostname on the machine where you've set up Fiddler as a reverse proxy) :

http://remoteHostname:8888/controller/action

  • Alternatively, you can compose a request by using another instance of Fiddler on a remote machine, using a URL similar to the one above. This will allow you to make either a GET or a POST request.

IMPORTANT: Once you've finished viewing your request(s), go back to Tools > Fiddler Options > Connections and remove the 'Allow remote computers to connect' option, otherwise 3rd parties will be able to bounce traffic through your server

Querying a linked sql server

try Select * from openquery("aa-db-dev01",'Select * from users') ,the database connection should be defined in he linked server configuration

How to change Apache Tomcat web server port number

Navigate to /tomcat-root/conf folder. Within you will find the server.xml file.

Open the server.xml in your preferred editor. Search the below similar statement (not exactly same as below will differ)

    <Connector port="8080" protocol="HTTP/1.1" 
           connectionTimeout="20000" 
           redirectPort="8443" />

Going to give the port number to 9090

     <Connector port="9090" protocol="HTTP/1.1" 
           connectionTimeout="20000" 
           redirectPort="8443" />

Save the file and restart the server. Now the tomcat will listen at port 9090

Unable to create/open lock file: /data/mongod.lock errno:13 Permission denied

For mac users:
Run ls -ld /data/db/
Output should be something like drwrx-xr-x 20 singh wheel 680 21 Jul 05:49 /data/db/
Where singh is the owner and wheel is the group it belongs to.
Run sudo chown -R singh:wheel /data/db
Run mongod

PostgreSQL database service

Your server running on port 5432 but in the properties, the port is set to 5433.

You must go to pgAdmin, click on database version, ex: PostgresSQL 10 and edit properties.

A new window appears and you need to change the port to 5432 [this is default port].

Angular 2 - Using 'this' inside setTimeout

You need to use Arrow function ()=> ES6 feature to preserve this context within setTimeout.

// var that = this;                             // no need of this line
this.messageSuccess = true;

setTimeout(()=>{                           //<<<---using ()=> syntax
      this.messageSuccess = false;
 }, 3000);

How can I check the system version of Android?

I can't comment on the answers, but there is a huge mistake in Kaushik's answer: SDK_INT is not the same as system version but actually refers to API Level.

if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH){
    //this code will be executed on devices running ICS or later
}

The value Build.VERSION_CODES.ICE_CREAM_SANDWICH equals 14. 14 is the API level of Ice Cream Sandwich, while the system version is 4.0. So if you write 4.0, your code will be executed on all devices starting from Donut, because 4 is the API level of Donut (Build.VERSION_CODES.DONUT equals 4).

if(Build.VERSION.SDK_INT >= 4.0){
    //this code will be executed on devices running on DONUT (NOT ICS) or later
}

This example is a reason why using 'magic number' is a bad habit.

Multiple axis line chart in excel

The picture you showd in the question is actually a chart made using JavaScript. It is actually very easy to plot multi-axis chart using JavaScript with the help of 3rd party libraries like HighChart.js or D3.js. Here I propose to use the Funfun Excel add-in which allows you to use JavaScript directly in Excel so you could plot chart like you've showed easily in Excel. Here I made an example using Funfun in Excel.

enter image description here

You could see in this chart you have one axis of Rainfall at the left side while two axis of Temperature and Sea-pressure level at the right side. This is also a combination of line chart and bar chart for different datasets. In this example, with the help of the Funfun add-in, I used HighChart.js to plot this chart.

Funfun also has an online editor in which you could test your JavaScript code with you data. You could check the detailed code of this example on the link below.

https://www.funfun.io/1/#/edit/5a43b416b848f771fbcdee2c

Edit: The content on the previous link has been changed so I posted a new link here. The link below is the original link https://www.funfun.io/1/#/edit/5a55dc978dfd67466879eb24

If you are satisfied with the result you achieved in the online editor, you could easily load the result into you Excel using the URL above. Of couse first you need to insert the Funfun add-in from Insert - My add-ins. Here are some screenshots showing how you could do this.

enter image description here

enter image description here

enter image description here

Disclosure: I'm a developer of Funfun

How do I create a Java string from the contents of a file?

That code will normalize line breaks, which may or may not be what you really want to do.

Here's an alternative which doesn't do that, and which is (IMO) simpler to understand than the NIO code (although it still uses java.nio.charset.Charset):

public static String readFile(String file, String csName)
            throws IOException {
    Charset cs = Charset.forName(csName);
    return readFile(file, cs);
}

public static String readFile(String file, Charset cs)
            throws IOException {
    // No real need to close the BufferedReader/InputStreamReader
    // as they're only wrapping the stream
    FileInputStream stream = new FileInputStream(file);
    try {
        Reader reader = new BufferedReader(new InputStreamReader(stream, cs));
        StringBuilder builder = new StringBuilder();
        char[] buffer = new char[8192];
        int read;
        while ((read = reader.read(buffer, 0, buffer.length)) > 0) {
            builder.append(buffer, 0, read);
        }
        return builder.toString();
    } finally {
        // Potential issue here: if this throws an IOException,
        // it will mask any others. Normally I'd use a utility
        // method which would log exceptions and swallow them
        stream.close();
    }        
}

How to make a Bootstrap accordion collapse when clicking the header div?

Here is the working example for Bootstrap 4.3

_x000D_
_x000D_
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js" integrity="sha384-q8i/X+965DzO0rT7abK41JStQIAqVgRVzpbzo5smXKp4YfRvH+8abtTE1Pi6jizo" crossorigin="anonymous"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js" integrity="sha384-UO2eT0CpHqdSJQ6hJty5KVphtPhzWj9WO1clHTMGa3JDZwrnQq4sF86dIHNDz0W1" crossorigin="anonymous"></script>_x000D_
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js" integrity="sha384-JjSmVgyd0p3pXB1rRibZUAYoIIy6OrQ6VrjIEaFf/nJGzIxFDsf4x0xIM+B07jRM" crossorigin="anonymous"></script>_x000D_
_x000D_
<link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384-ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">_x000D_
_x000D_
_x000D_
<div class="accordion" id="accordionExample">_x000D_
                <div class="card">_x000D_
                    <div class="card-header" id="headingOne" data-toggle="collapse" data-target="#collapseOne" aria-expanded="true" aria-controls="collapseOne">_x000D_
                        <h2 class="mb-0">_x000D_
                            <button class="btn btn-link" type="button" >_x000D_
                                Collapsible Group Item #1_x000D_
                            </button>_x000D_
                        </h2>_x000D_
                    </div>_x000D_
_x000D_
                    <div id="collapseOne" class="collapse show" aria-labelledby="headingOne" data-parent="#accordionExample">_x000D_
                        <div class="card-body">_x000D_
                            _x000D_
                        </div>_x000D_
                    </div>_x000D_
                </div>_x000D_
                <div class="card">_x000D_
                    <div class="card-header" id="headingTwo" data-toggle="collapse" data-target="#collapseTwo" aria-expanded="false" aria-controls="collapseTwo">_x000D_
                        <h2 class="mb-0">_x000D_
                            <button class="btn btn-link collapsed" type="button" >_x000D_
                                Collapsible Group Item #2_x000D_
                            </button>_x000D_
                        </h2>_x000D_
                    </div>_x000D_
                    <div id="collapseTwo" class="collapse" aria-labelledby="headingTwo" data-parent="#accordionExample">_x000D_
                        <div class="card-body">_x000D_
                            _x000D_
                        </div>_x000D_
                    </div>_x000D_
                </div>_x000D_
                <div class="card">_x000D_
                    <div class="card-header" id="headingThree" data-toggle="collapse" data-target="#collapseThree" aria-expanded="false" aria-controls="collapseThree">_x000D_
                        <h2 class="mb-0">_x000D_
                            <button class="btn btn-link collapsed" type="button" >_x000D_
                                Collapsible Group Item #3_x000D_
                            </button>_x000D_
                        </h2>_x000D_
                    </div>_x000D_
                    <div id="collapseThree" class="collapse" aria-labelledby="headingThree" data-parent="#accordionExample">_x000D_
                        <div class="card-body">_x000D_
                            _x000D_
                        </div>_x000D_
                    </div>_x000D_
                </div>_x000D_
            </div>
_x000D_
_x000D_
_x000D_

How can I tail a log file in Python?

Adapting Ijaz Ahmad Khan's answer to only yield lines when they are completely written (lines end with a newline char) gives a pythonic solution with no external dependencies:

def follow(file) -> Iterator[str]:
    """ Yield each line from a file as they are written. """
    line = ''
    while True:
        tmp = file.readline()
        if tmp is not None:
            line += tmp
            if line.endswith("\n"):
                yield line
                line = ''
        else:
            time.sleep(0.1)


if __name__ == '__main__':
    for line in follow(open("test.txt", 'r')):
        print(line, end='')

What is System, out, println in System.out.println() in Java

The first answer you posted (System is a built-in class...) is pretty spot on.

You can add that the System class contains large portions which are native and that is set up by the JVM during startup, like connecting the System.out printstream to the native output stream associated with the "standard out" (console).

Ruby send JSON request

HTTParty makes this a bit easier I think (and works with nested json etc, which didn't seem to work in other examples I've seen.

require 'httparty'
HTTParty.post("http://localhost:3000/api/v1/users", body: {user: {email: '[email protected]', password: 'secret'}}).body

How to find out line-endings in a text file?

In the bash shell, try cat -v <filename>. This should display carriage-returns for windows files.

(This worked for me in rxvt via Cygwin on Windows XP).

Editor's note: cat -v visualizes \r (CR) chars. as ^M. Thus, line-ending \r\n sequences will display as ^M at the end of each output line. cat -e will additionally visualize \n, namely as $. (cat -et will additionally visualize tab chars. as ^I.)

how to use getSharedPreferences in android

If someone used this:

val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context)

PreferenceManager is now depricated, refactor to this:

val sharedPreferences = context.getSharedPreferences(context.packageName + "_preferences", Context.MODE_PRIVATE)

Decimal or numeric values in regular expression validation

Actually, none of the given answers are fully cover the request.
As the OP didn't provided a specific use case or types of numbers, I will try to cover all possible cases and permutations.

Regular Numbers

Whole Positive

This number is usually called unsigned integer, but you can also call it a positive non-fractional number, include zero. This includes numbers like 0, 1 and 99999.
The Regular Expression that covers this validation is:

/^(0|[1-9]\d*)$/

Test This Regex

Whole Positive and Negative

This number is usually called signed integer, but you can also call it a non-fractional number. This includes numbers like 0, 1, 99999, -99999, -1 and -0.
The Regular Expression that covers this validation is:

/^-?(0|[1-9]\d*)$/

Test This Regex

As you probably noticed, I have also included -0 as a valid number. But, some may argue with this usage, and tell that this is not a real number (you can read more about Signed Zero here). So, if you want to exclude this number from this regex, here's what you should use instead:

/^-?(0|[1-9]\d*)(?<!-0)$/

Test This Regex

All I have added is (?<!-0), which means not to include -0 before this assertion. This (?<!...) assertion called negative lookbehind, which means that any phrase replaces the ... should not appear before this assertion. Lookbehind has limitations, like the phrase cannot include quantifiers. That's why for some cases I'll be using Lookahead instead, which is the same, but in the opposite way.

Many regex flavors, including those used by Perl and Python, only allow fixed-length strings. You can use literal text, character escapes, Unicode escapes other than \X, and character classes. You cannot use quantifiers or backreferences. You can use alternation, but only if all alternatives have the same length. These flavors evaluate lookbehind by first stepping back through the subject string for as many characters as the lookbehind needs, and then attempting the regex inside the lookbehind from left to right.

You can read more bout Lookaround assertions here.

Fractional Numbers

Positive

This number is usually called unsigned float or unsigned double, but you can also call it a positive fractional number, include zero. This includes numbers like 0, 1, 0.0, 0.1, 1.0, 99999.000001, 5.10.
The Regular Expression that covers this validation is:

/^(0|[1-9]\d*)(\.\d+)?$/

Test This Regex

Some may say, that numbers like .1, .0 and .00651 (same as 0.1, 0.0 and 0.00651 respectively) are also valid fractional numbers, and I cannot disagree with them. So here is a regex that is additionally supports this format:

/^(0|[1-9]\d*)?(\.\d+)?(?<=\d)$/

Test This Regex

Negative and Positive

This number is usually called signed float or signed double, but you can also call it a fractional number. This includes numbers like 0, 1, 0.0, 0.1, 1.0, 99999.000001, 5.10, -0, -1, -0.0, -0.1, -99999.000001, 5.10.
The Regular Expression that covers this validation is:

/^-?(0|[1-9]\d*)(\.\d+)?$/

Test This Regex

For non -0 believers:

/^(?!-0(\.0+)?$)-?(0|[1-9]\d*)(\.\d+)?$/

Test This Regex

For those who want to support also the invisible zero representations, like .1, -.1, use the following regex:

/^-?(0|[1-9]\d*)?(\.\d+)?(?<=\d)$/

Test This Regex

The combination of non -0 believers and invisible zero believers, use this regex:

/^(?!-0?(\.0+)?$)-?(0|[1-9]\d*)?(\.\d+)?(?<=\d)$/

Test This Regex

Numbers with a Scientific Notation (AKA Exponential Notation)

Some may want to support in their validations, numbers with a scientific character e, which is by the way, an absolutely valid number, it is created for shortly represent a very long numbers. You can read more about Scientific Notation here. These numbers are usually looks like 1e3 (which is 1000), 1e-3 (which is 0.001) and are fully supported by many major programming languages (e.g. JavaScript). You can test it by checking if the expression '1e3'==1000 returns true.
I will divide the support for all the above sections, including numbers with scientific notation.

Regular Numbers

Whole positive number regex validation, supports numbers like 6e4, 16e-10, 0e0 but also regular numbers like 0, 11:

/^(0|[1-9]\d*)(e-?(0|[1-9]\d*))?$/i

Test This Regex

Whole positive and negative number regex validation, supports numbers like -6e4, -16e-10, -0e0 but also regular numbers like -0, -11 and all the whole positive numbers above:

/^-?(0|[1-9]\d*)(e-?(0|[1-9]\d*))?$/i

Test This Regex

Whole positive and negative number regex validation for non -0 believers, same as the above, except now it forbids numbers like -0, -0e0, -0e5 and -0e-6:

/^(?!-0)-?(0|[1-9]\d*)(e-?(0|[1-9]\d*))?$/i

Test This Regex

Fractional Numbers

Positive number regex validation, supports also the whole numbers above, plus numbers like 0.1e3, 56.0e-3, 0.0e10 and 1.010e0:

/^(0|[1-9]\d*)(\.\d+)?(e-?(0|[1-9]\d*))?$/i

Test This Regex

Positive number with invisible zero support regex validation, supports also the above positive numbers, in addition numbers like .1e3, .0e0, .0e-5 and .1e-7:

/^(0|[1-9]\d*)?(\.\d+)?(?<=\d)(e-?(0|[1-9]\d*))?$/i

Test This Regex

Negative and positive number regex validation, supports the positive numbers above, but also numbers like -0e3, -0.1e0, -56.0e-3 and -0.0e10:

/^-?(0|[1-9]\d*)(\.\d+)?(e-?(0|[1-9]\d*))?$/i

Test This Regex

Negative and positive number regex validation fro non -0 believers, same as the above, except now it forbids numbers like -0, -0.00000, -0.0e0, -0.00000e5 and -0e-6:

/^(?!-0(\.0+)?(e|$))-?(0|[1-9]\d*)(\.\d+)?(e-?(0|[1-9]\d*))?$/i

Test This Regex

Negative and positive number with invisible zero support regex validation, supports also the above positive and negative numbers, in addition numbers like -.1e3, -.0e0, -.0e-5 and -.1e-7:

/^-?(0|[1-9]\d*)?(\.\d+)?(?<=\d)(e-?(0|[1-9]\d*))?$/i

Test This Regex

Negative and positive number with the combination of non -0 believers and invisible zero believers, same as the above, but forbids numbers like -.0e0, -.0000e15 and -.0e-19:

/^(?!-0?(\.0+)?(e|$))-?(0|[1-9]\d*)?(\.\d+)?(?<=\d)(e-?(0|[1-9]\d*))?$/i

Test This Regex

Numbers with Hexadecimal Representation

In many programming languages, string representation of hexadecimal number like 0x4F7A may be easily cast to decimal number 20346.
Thus, one may want to support it in his validation script.
The following Regular Expression supports only hexadecimal numbers representations:

/^0x[0-9a-f]+$/i

Test This Regex

All Permutations

These final Regular Expressions, support the invisible zero numbers.

Signed Zero Believers

/^(-?(0|[1-9]\d*)?(\.\d+)?(?<=\d)(e-?(0|[1-9]\d*))?|0x[0-9a-f]+)$/i

Test This Regex

Non Signed Zero Believers

/^((?!-0?(\.0+)?(e|$))-?(0|[1-9]\d*)?(\.\d+)?(?<=\d)(e-?(0|[1-9]\d*))?|0x[0-9a-f]+)$/i

Test This Regex

Hope I covered all number permutations that are supported in many programming languages.
Good luck!


Oh, forgot to mention, that those who want to validate a number includes a thousand separator, you should clean all the commas (,) first, as there may be any type of separator out there, you can't actually cover them all.
But you can remove them first, before the number validation:

//JavaScript
function clearSeparators(number)
{
    return number.replace(/,/g,'');
}

Similar post on my blog.

How do I import a .bak file into Microsoft SQL Server 2012?

You can use the following script if you don't wish to use Wizard;

RESTORE DATABASE myDB
FROM  DISK = N'C:\BackupDB.bak' 
WITH  REPLACE,RECOVERY,  
MOVE N'HRNET' TO N'C:\MSSQL\Data\myDB.mdf',  
MOVE N'HRNET_LOG' TO N'C:\MSSQL\Data\myDB.ldf'

Split a python list into other "sublists" i.e smaller lists

Actually I think using plain slices is the best solution in this case:

for i in range(0, len(data), 100):
    chunk = data[i:i + 100]
    ...

If you want to avoid copying the slices, you could use itertools.islice(), but it doesn't seem to be necessary here.

The itertools() documentation also contains the famous "grouper" pattern:

def grouper(n, iterable, fillvalue=None):
    "grouper(3, 'ABCDEFG', 'x') --> ABC DEF Gxx"
    args = [iter(iterable)] * n
    return izip_longest(fillvalue=fillvalue, *args)

You would need to modify it to treat the last chunk correctly, so I think the straight-forward solution using plain slices is preferable.

How to downgrade php from 7.1.1 to 5.6 in xampp 7.1.1?

It is very easy to do, all you need to do is 1) download 5.6 from [1]: https://sourceforge.net/projects/xampp/files/XAMPP%20Windows/5.6.36/, the run the setup and install in folder "xampp"

2) download 7.6 from [https://sourceforge.net/projects/xampp/files/XAMPP%20Windows/7.4.2/xampp-portable-windows-x64-7.4.2-0-VC15-installer.exe/download][1] and run the setup in "xampp2"

NOte: after that you now have separate xampp installed in your system. all you do now is to run each xampp as a separate entity. Alway quite the 5.6 if you want to run 7.6

What is the 'pythonic' equivalent to the 'fold' function from functional programming?

I may be quite late to the party, but we can create custom foldr using simple lambda calculus and curried function. Here is my implementation of foldr in python.

def foldr(func):
    def accumulator(acc):
        def listFunc(l):
            if l:
                x = l[0]
                xs = l[1:]
                return func(x)(foldr(func)(acc)(xs))
            else:
                return acc
        return listFunc
    return accumulator  


def curried_add(x):
    def inner(y):
        return x + y
    return inner

def curried_mult(x):
    def inner(y):
        return x * y
    return inner

print foldr(curried_add)(0)(range(1, 6))
print foldr(curried_mult)(1)(range(1, 6))

Even though the implementation is recursive (might be slow), it will print the values 15 and 120 respectively

How to set the max value and min value of <input> in html5 by javascript or jquery?

Try this:

<input type="number" max="???" min="???" step="0.5" id="myInput"/>

$("#myInput").attr({
   "max" : 10,
   "min" : 2
});

Note:This will set max and min value only to single input

The ScriptManager must appear before any controls that need it

The ScriptManager is a web control that you register in the page using

<asp:ScriptManager ID="ScriptManger1" runat="Server" />

inside the Form tag

Angular2 material dialog has issues - Did you add it to @NgModule.entryComponents?

You need to add dynamically created components to entryComponents inside your @NgModule

@NgModule({
  declarations: [
    AppComponent,
    LoginComponent,
    DashboardComponent,
    HomeComponent,
    DialogResultExampleDialog        
  ],
  entryComponents: [DialogResultExampleDialog]

Note: In some cases entryComponents under lazy loaded modules will not work, as a workaround put them in your app.module (root)

Copy struct to struct in C

For simple structures you can either use memcpy like you do, or just assign from one to the other:

RTCclk = RTCclkBuffert;

The compiler will create code to copy the structure for you.


An important note about the copying: It's a shallow copy, just like with memcpy. That means if you have e.g. a structure containing pointers, it's only the actual pointers that will be copied and not what they point to, so after the copy you will have two pointers pointing to the same memory.

How do we determine the number of days for a given month in python

Use calendar.monthrange:

>>> from calendar import monthrange
>>> monthrange(2011, 2)
(1, 28)

Just to be clear, monthrange supports leap years as well:

>>> from calendar import monthrange
>>> monthrange(2012, 2)
(2, 29)

As @mikhail-pyrev mentions in a comment:

First number is weekday of first day of the month, second number is number of days in said month.

Java: how to add image to Jlabel?

You have to supply to the JLabel an Icon implementation (i.e ImageIcon). You can do it trough the setIcon method, as in your question, or through the JLabel constructor:

Image image=GenerateImage.toImage(true);  //this generates an image file
ImageIcon icon = new ImageIcon(image); 
JLabel thumb = new JLabel();
thumb.setIcon(icon);

I recommend you to read the Javadoc for JLabel, Icon, and ImageIcon. Also, you can check the How to Use Labels Tutorial, for more information.

What's the easy way to auto create non existing dir in ansible

Right now, this is the only way

- name: Ensures {{project_root}}/conf dir exists
  file: path={{project_root}}/conf state=directory
- name: Copy file
  template:
    src: code.conf.j2
    dest: "{{project_root}}/conf/code.conf"

How to open select file dialog via js?

_x000D_
_x000D_
function promptFile(contentType, multiple) {
  var input = document.createElement("input");
  input.type = "file";
  input.multiple = multiple;
  input.accept = contentType;
  return new Promise(function(resolve) {
    document.activeElement.onfocus = function() {
      document.activeElement.onfocus = null;
      setTimeout(resolve, 500);
    };
    input.onchange = function() {
      var files = Array.from(input.files);
      if (multiple)
        return resolve(files);
      resolve(files[0]);
    };
    input.click();
  });
}
function promptFilename() {
  promptFile().then(function(file) {
    document.querySelector("span").innerText = file && file.name || "no file selected";
  });
}
_x000D_
<button onclick="promptFilename()">Open</button>
<span></span>
_x000D_
_x000D_
_x000D_

How to remove button shadow (android)

Instead of a Button, you can use a TextView and add a click listener in the java code.

I.e.

in the activity layout xml:

<TextView
    android:id="@+id/btn_text_view"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/colorPrimaryDark"
    android:text="@string/btn_text"
    android:gravity="center"
    android:textColor="@color/colorAccent"
    android:fontFamily="sans-serif-medium"
    android:textAllCaps="true" />

in the activity java file:

TextView btnTextView = (TextView) findViewById(R.id.btn_text_view);
btnTextView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // handler code
            }
        });

How to Right-align flex item?

Example code based on answer by TetraDev

Images on right:

_x000D_
_x000D_
* {_x000D_
  outline: .4px dashed red;_x000D_
}_x000D_
_x000D_
.main {_x000D_
  display: flex;_x000D_
  flex-direction: row;_x000D_
  align-items: center;_x000D_
}_x000D_
_x000D_
h1 {_x000D_
  flex-basis: 100%;_x000D_
}_x000D_
_x000D_
img {_x000D_
  margin: 0 5px;_x000D_
  height: 30px;_x000D_
}
_x000D_
<div class="main">_x000D_
  <h1>Secure Payment</h1>_x000D_
  <img src="https://i.stack.imgur.com/i65gn.png">_x000D_
  <img src="https://i.stack.imgur.com/i65gn.png">_x000D_
</div>
_x000D_
_x000D_
_x000D_

Images on left:

_x000D_
_x000D_
* {_x000D_
  outline: .4px dashed red;_x000D_
}_x000D_
_x000D_
.main {_x000D_
  display: flex;_x000D_
  flex-direction: row;_x000D_
  align-items: center;_x000D_
}_x000D_
_x000D_
h1 {_x000D_
  flex-basis: 100%;_x000D_
  text-align: right;_x000D_
}_x000D_
_x000D_
img {_x000D_
  margin: 0 5px;_x000D_
  height: 30px;_x000D_
}
_x000D_
<div class="main">_x000D_
  <img src="https://i.stack.imgur.com/i65gn.png">_x000D_
  <img src="https://i.stack.imgur.com/i65gn.png">_x000D_
  <h1>Secure Payment</h1>_x000D_
</div>
_x000D_
_x000D_
_x000D_

How to install maven on redhat linux

I made the following script:

#!/bin/bash

# Target installation location
MAVEN_HOME="/your/path/here"

# Link to binary tar.gz archive
# See https://maven.apache.org/download.cgi?html_a_name#Files
MAVEN_BINARY_TAR_GZ_ARCHIVE="http://www.trieuvan.com/apache/maven/maven-3/3.3.9/binaries/apache-maven-3.3.9-bin.tar.gz"

# Configuration parameters used to start up the JVM running Maven, i.e. "-Xms256m -Xmx512m"
# See https://maven.apache.org/configure.html
MAVEN_OPTS="" # Optional (not needed)

if [[ ! -d $MAVEN_HOME ]]; then
  # Create nonexistent subdirectories recursively
  mkdir -p $MAVEN_HOME

  # Curl location of tar.gz archive & extract without first directory
  curl -L $MAVEN_BINARY_TAR_GZ_ARCHIVE | tar -xzf - -C $MAVEN_HOME --strip 1

  # Creating a symbolic/soft link to Maven in the primary directory of executable commands on the system
  ln -s $MAVEN_HOME/bin/mvn /usr/bin/mvn

  # Permanently set environmental variable (if not null)
  if [[ -n $MAVEN_OPTS ]]; then
    echo "export MAVEN_OPTS=$MAVEN_OPTS" >> ~/.bashrc
  fi

  # Using MAVEN_HOME, MVN_HOME, or M2 as your env var is irrelevant, what counts
  # is your $PATH environment.
  # See http://stackoverflow.com/questions/26609922/maven-home-mvn-home-or-m2-home
  echo "export PATH=$MAVEN_HOME/bin:$PATH" >> ~/.bashrc
else
  # Do nothing if target installation directory already exists
  echo "'$MAVEN_HOME' already exists, please uninstall existing maven first."
fi

How to calculate percentage when old value is ZERO

You can add 1 to each example New = 5; old = 0;

(1+new) - (old+1) / (old +1) 5/ 1 * 100 ==> 500%

How do I draw a grid onto a plot in Python?

To show a grid line on every tick, add

plt.grid(True)

For example:

import matplotlib.pyplot as plt

points = [
    (0, 10),
    (10, 20),
    (20, 40),
    (60, 100),
]

x = list(map(lambda x: x[0], points))
y = list(map(lambda x: x[1], points))

plt.scatter(x, y)
plt.grid(True)

plt.show()

enter image description here


In addition, you might want to customize the styling (e.g. solid line instead of dashed line), add:

plt.rc('grid', linestyle="-", color='black')

For example:

import matplotlib.pyplot as plt

points = [
    (0, 10),
    (10, 20),
    (20, 40),
    (60, 100),
]

x = list(map(lambda x: x[0], points))
y = list(map(lambda x: x[1], points))

plt.rc('grid', linestyle="-", color='black')
plt.scatter(x, y)
plt.grid(True)

plt.show()

enter image description here

Git: Cannot see new remote branch

Check whether .git/config contains

[remote "origin"]
    url = …
    fetch = +refs/heads/master:refs/remotes/origin/master

If so, change it to say

[remote "origin"]
    url = …
    fetch = +refs/heads/*:refs/remotes/origin/*

Then you should be able to use it:

$ git fetch
remote: Counting objects: …
remote: Compressing objects: ..
Unpacking objects: …
remote: …
From …
 * [new branch]            branchname -> origin/branchname
$ git checkout branchname
Branch branchname set up to track remote branch branchname from origin.
Switched to a new branch 'branchname'

Warning: mysql_connect(): Access denied for user 'root'@'localhost' (using password: YES)

try $conn = mysql_connect("localhost", "root") or $conn = mysql_connect("localhost", "root", "")

'pip' is not recognized as an internal or external command

A very simple way to get around this is to open the path where pip is installed in File Explorer, and click on the path, then type cmd, this sets the path, allowing you to install way easier.

I ran into the same issue a couple days ago and all the other methods didn't work for me.

Mapping object to dictionary and vice versa

I'd highly recommend the Castle DictionaryAdapter, easily one of that project's best-kept secrets. You only need to define an interface with the properties you want, and in one line of code the adapter will generate an implementation, instantiate it, and synchronize its values with a dictionary you pass in. I use it to strongly-type my AppSettings in a web project:

var appSettings =
  new DictionaryAdapterFactory().GetAdapter<IAppSettings>(ConfigurationManager.AppSettings);

Note that I did not need to create a class that implements IAppSettings - the adapter does that on the fly. Also, although in this case I'm only reading, in theory if I were setting property values on appSettings, the adapter would keep the underlying dictionary in sync with those changes.

SSL Error When installing rubygems, Unable to pull data from 'https://rubygems.org/

For Windows user:

After installing Ruby 2.2.3 (+ rubygems 2.5.1) successfully on a test machine with access to the internet, I had this SSL error when I installed bundler on a production machine, within the network.

As I had network access limitations, and there was no way to change the settings for SSL access, and based on the error messages, I performed the steps below to be able to finish the installation of the bundler (this may sound crazy, but it worked...).

Through a machine with unrestricted access to the internet, downloaded the following files:

I added these files on an intranet server, keeping the folder structure of the links above:

  • $INTRANET_HOME

spec.4.8.gz e latest_specs.4.8.gz

  • $INTRANET_HOME\quick\Marshal.4.8

bundler-1.11.2.gemspec.rz

  • $INTRANET_HOME\gems

bundler-1.11.2.gem

Then I added my intranet to access gem source:

gem sources -a http://mydomain.com.br

I have run with the success the "gem install bundler" after installation, all it took was remove my intranet of the gem:

gem sources -r http://mydomain.com.br

I hope that is useful in any similar situation....

"Post Image data using POSTMAN"

That's not how you send file on postman. What you did is sending a string which is the path of your image, nothing more.

What you should do is;

  1. After setting request method to POST, click to the 'body' tab.
  2. Select form-data. At first line, you'll see text boxes named key and value. Write 'image' to the key. You'll see value type which is set to 'text' as default. Make it File and upload your file.
  3. Then select 'raw' and paste your json file. Also just next to the binary choice, You'll see 'Text' is clicked. Make it JSON.

form-data section

raw section

You're ready to go.

In your Django view,

from rest_framework.views import APIView
from rest_framework.parsers import MultiPartParser
from rest_framework.decorators import parser_classes

@parser_classes((MultiPartParser, ))
class UploadFileAndJson(APIView):

    def post(self, request, format=None):
        thumbnail = request.FILES["file"]
        info = json.loads(request.data['info'])
        ...
        return HttpResponse()

How to extract text from a PDF file?

Camelot seems a fairly powerful solution to extract tables from PDFs in Python.

At first sight it seems to achieve almost as accurate extraction as the tabula-py package suggested by CreekGeek, which is already waaaaay above any other posted solution as of today in terms of reliability, but it is supposedly much more configurable. Furthermore it has its own accuracy indicator (results.parsing_report), and great debugging features.

Both Camelot and Tabula provide the results as Pandas’ DataFrames, so it is easy to adjust tables afterwards.

pip install camelot-py

(Not to be confused with the camelot package.)

import camelot

df_list = []
results = camelot.read_pdf("file.pdf", ...)
for table in results:
    print(table.parsing_report)
    df_list.append(results[0].df)

It can also output results as CSV, JSON, HTML or Excel.

Camelot comes at the expense of a number of dependencies.

NB : Since my input is pretty complex with many different tables I ended up using both Camelot and Tabula, depending on the table, to achieve the best results.

type object 'datetime.datetime' has no attribute 'datetime'

If you have used:

from datetime import datetime

Then simply write the code as:

date = datetime(int(year), int(month), 1)

But if you have used:

import datetime

then only you can write:

date = datetime.datetime(int(2005), int(5), 1)

Java HTTP Client Request with defined timeout

HttpParams is deprecated in the new Apache HTTPClient library. Using the code provided by Laz leads to deprecation warnings.

I suggest to use RequestConfig instead on your HttpGet or HttpPost instance:

final RequestConfig params = RequestConfig.custom().setConnectTimeout(3000).setSocketTimeout(3000).build();
httpPost.setConfig(params);

Binding a list in @RequestParam

Or you could just do it that way:

public String controllerMethod(@RequestParam(value="myParam[]") String[] myParams){
    ....
}

That works for example for forms like this:

<input type="checkbox" name="myParam[]" value="myVal1" />
<input type="checkbox" name="myParam[]" value="myVal2" />

This is the simplest solution :)

Using OpenGl with C#?

XNA 2.0 requires a minimum of a shader 1.1 card. While old tech, not everyone has one. Some newer laptops (in our experience Toshiba tablets with Intel graphics) have no shader 1.1 support. XNA simply wont run on these machines.

This is a significant issue for us and we have shifted to Tao and OpenGL. Plus with Tao we have bindings for audio & Lua support.

Rails 4: assets not loading in production

Rails 4 no longer generates the non fingerprinted version of the asset: stylesheets/style.css will not be generated for you.

If you use stylesheet_link_tag then the correct link to your stylesheet will be generated

In addition styles.css should be in config.assets.precompile which is the list of things that are precompiled

Getting cursor position in Python

win32gui.GetCursorPos(point)

This retrieves the cursor's position, in screen coordinates - point = (x,y)

flags, hcursor, (x,y) = win32gui.GetCursorInfo()

Retrieves information about the global cursor.

Links:

I am assuming that you would be using python win32 API bindings or pywin32.

Create intermediate folders if one doesn't exist

Use this code spinet for create intermediate folders if one doesn't exist while creating/editing file:

File outFile = new File("/dir1/dir2/dir3/test.file");
outFile.getParentFile().mkdirs();
outFile.createNewFile();

Is there a way to check which CSS styles are being used or not used on a web page?

Without any third-party tools and any app, you can find unused CSS and javascript by using chrome dev tools in the coverage tab. read the post below from google developers. chrome coverage tab

Consistency of hashCode() on a Java string

The hashcode will be calculated based on the ASCII values of the characters in the String.

This is the implementation in the String Class is as follows

public int hashCode() {
    int h = hash;
    if (h == 0 && value.length > 0) {
        hash = h = isLatin1() ? StringLatin1.hashCode(value)
                              : StringUTF16.hashCode(value);
    }
    return h;
}

Collisions in hashcode are unavoidable. For example, the strings "Ea" and "FB" give the same hashcode as 2236

ERROR in Cannot find module 'node-sass'

This is what worked for me. I first uninstall node-sass. Then install it back.

npm uninstall node-sass
npm install --save-dev node-sass

How to copy text to the client's clipboard using jQuery?

Copying to the clipboard is a tricky task to do in Javascript in terms of browser compatibility. The best way to do it is using a small flash. It will work on every browser. You can check it in this article.

Here's how to do it for Internet Explorer:

function copy (str)
{
    //for IE ONLY!
    window.clipboardData.setData('Text',str);
}

Reading data from DataGridView in C#

something like

for (int rows = 0; rows < dataGrid.Rows.Count; rows++)
{
     for (int col= 0; col < dataGrid.Rows[rows].Cells.Count; col++)
    {
        string value = dataGrid.Rows[rows].Cells[col].Value.ToString();

    }
} 

example without using index

foreach (DataGridViewRow row in dataGrid.Rows)
{ 
    foreach (DataGridViewCell cell in row.Cells)
    {
        string value = cell.Value.ToString();

    }
}

Android ListView with Checkbox and all clickable

this code works on my proyect and i can select the listview item and checkbox

<?xml version="1.0" encoding="utf-8"?>
<!-- Single List Item Design -->
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:clickable="true" >

    <TextView
        android:id="@+id/label"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="4" />

    <CheckBox
        android:id="@+id/check"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:focusable="false"
        android:text="" >
    </CheckBox>

</LinearLayout>

How to create cron job using PHP?

Type the following in the linux/ubuntu terminal

 crontab -e 

select an editor (sometime it asks for the editor) and this to run for every minute

*       *       *       *       *       /usr/bin/php path/to/cron.php &> /dev/null

Amazon S3 - HTTPS/SSL - Is it possible?

payton109’s answer is correct if you’re in the default US-EAST-1 region. If your bucket is in a different region, use a slightly different URL:

https://s3-<region>.amazonaws.com/your.domain.com/some/asset

Where <region> is the bucket location name. For example, if your bucket is in the us-west-2 (Oregon) region, you can do this:

https://s3-us-west-2.amazonaws.com/your.domain.com/some/asset

Go install fails with error: no install location for directory xxx outside GOPATH

For what it's worth, here's my .bash_profile, that works well for me on a mac with Atom, after installing go with Homebrew:

export GOROOT=`go env GOROOT`
export GOPATH=/Users/yy/Projects/go
export GOBIN=$GOPATH/bin
export PATH=$PATH:$GOBIN

How to reload a page after the OK click on the Alert Page

Try this code..

IN PHP Code

echo "<script type='text/javascript'>".
      "alert('Success to add the task to a project.');
       location.reload;".
     "</script>";

IN Javascript

function refresh()
{
    alert("click ok to refresh  page");
    location.reload();
}

Ignoring directories in Git repositories on Windows

On Unix:

touch .gitignore

On Windows:

echo > .gitignore

These commands executed in a terminal will create a .gitignore file in the current location.

Then just add information to this .gitignore file (using Notepad++ for example) which files or folders should be ignored. Save your changes. That's it :)

More information: .gitignore

Toad for Oracle..How to execute multiple statements?

I prefer the Execute via SQL*Plus option. It's in the little down-arrow menu under the "Execute as script" toolbar button.

How to truncate text in Angular2?

Like this:

{{ data.title | slice:0:20 }}

And if you want the ellipsis, here's a workaround

{{ data.title | slice:0:20 }}...

Install dependencies globally and locally using package.json

This is a bit old but I ran into the requirement so here is the solution I came up with.

The Problem:

Our development team maintains many .NET web application products we are migrating to AngularJS/Bootstrap. VS2010 does not lend itself easily to custom build processes and my developers are routinely working on multiple releases of our products. Our VCS is Subversion (I know, I know. I'm trying to move to Git but my pesky marketing staff is so demanding) and a single VS solution will include several separate projects. I needed my staff to have a common method for initializing their development environment without having to install the same Node packages (gulp, bower, etc.) several times on the same machine.

TL;DR:

  1. Need "npm install" to install the global Node/Bower development environment as well as all locally required packages for a .NET product.

  2. Global packages should be installed only if not already installed.

  3. Local links to global packages must be created automatically.

The Solution:

We already have a common development framework shared by all developers and all products so I created a NodeJS script to install the global packages when needed and create the local links. The script resides in "....\SharedFiles" relative to the product base folder:

/*******************************************************************************
* $Id: npm-setup.js 12785 2016-01-29 16:34:49Z sthames $
* ==============================================================================
* Parameters: 'links' - Create links in local environment, optional.
* 
* <p>NodeJS script to install common development environment packages in global
* environment. <c>packages</c> object contains list of packages to install.</p>
* 
* <p>Including 'links' creates links in local environment to global packages.</p>
* 
* <p><b>npm ls -g --json</b> command is run to provide the current list of 
* global packages for comparison to required packages. Packages are installed 
* only if not installed. If the package is installed but is not the required 
* package version, the existing package is removed and the required package is 
* installed.</p>.
*
* <p>When provided as a "preinstall" script in a "package.json" file, the "npm
* install" command calls this to verify global dependencies are installed.</p>
*******************************************************************************/
var exec = require('child_process').exec;
var fs   = require('fs');
var path = require('path');

/*---------------------------------------------------------------*/
/* List of packages to install and 'from' value to pass to 'npm  */
/* install'. Value must match the 'from' field in 'npm ls -json' */
/* so this script will recognize a package is already installed. */
/*---------------------------------------------------------------*/
var packages = 
  {
  "bower"                      :                      "[email protected]", 
  "event-stream"               :               "[email protected]",
  "gulp"                       :                       "[email protected]",
  "gulp-angular-templatecache" : "[email protected]",
  "gulp-clean"                 :                 "[email protected]", 
  "gulp-concat"                :                "[email protected]",
  "gulp-debug"                 :                 "[email protected]",
  "gulp-filter"                :                "[email protected]",
  "gulp-grep-contents"         :         "[email protected]",
  "gulp-if"                    :                    "[email protected]", 
  "gulp-inject"                :                "[email protected]", 
  "gulp-minify-css"            :            "[email protected]",
  "gulp-minify-html"           :           "[email protected]",
  "gulp-minify-inline"         :         "[email protected]",
  "gulp-ng-annotate"           :           "[email protected]",
  "gulp-processhtml"           :           "[email protected]",
  "gulp-rev"                   :                   "[email protected]",
  "gulp-rev-replace"           :           "[email protected]",
  "gulp-uglify"                :                "[email protected]",
  "gulp-useref"                :                "[email protected]",
  "gulp-util"                  :                  "[email protected]",
  "lazypipe"                   :                   "[email protected]",
  "q"                          :                          "[email protected]",
  "through2"                   :                   "[email protected]",

  /*---------------------------------------------------------------*/
  /* fork of 0.2.14 allows passing parameters to main-bower-files. */
  /*---------------------------------------------------------------*/
  "bower-main"                 : "git+https://github.com/Pyo25/bower-main.git" 
  }

/*******************************************************************************
* run */
/**
* Executes <c>cmd</c> in the shell and calls <c>cb</c> on success. Error aborts.
* 
* Note: Error code -4082 is EBUSY error which is sometimes thrown by npm for 
* reasons unknown. Possibly this is due to antivirus program scanning the file 
* but it sometimes happens in cases where an antivirus program does not explain 
* it. The error generally will not happen a second time so this method will call 
* itself to try the command again if the EBUSY error occurs.
* 
* @param  cmd  Command to execute.
* @param  cb   Method to call on success. Text returned from stdout is input.
*******************************************************************************/
var run = function(cmd, cb)
  {
  /*---------------------------------------------*/
  /* Increase the maxBuffer to 10MB for commands */
  /* with a lot of output. This is not necessary */
  /* with spawn but it has other issues.         */
  /*---------------------------------------------*/
  exec(cmd, { maxBuffer: 1000*1024 }, function(err, stdout)
    {
    if      (!err)                   cb(stdout);
    else if (err.code | 0 == -4082) run(cmd, cb);
    else throw err;
    });
  };

/*******************************************************************************
* runCommand */
/**
* Logs the command and calls <c>run</c>.
*******************************************************************************/
var runCommand = function(cmd, cb)
  {
  console.log(cmd);
  run(cmd, cb);
  }

/*******************************************************************************
* Main line
*******************************************************************************/
var doLinks  = (process.argv[2] || "").toLowerCase() == 'links';
var names    = Object.keys(packages);
var name;
var installed;
var links;

/*------------------------------------------*/
/* Get the list of installed packages for   */
/* version comparison and install packages. */
/*------------------------------------------*/
console.log('Configuring global Node environment...')
run('npm ls -g --json', function(stdout)
  {
  installed = JSON.parse(stdout).dependencies || {};
  doWhile();
  });

/*--------------------------------------------*/
/* Start of asynchronous package installation */
/* loop. Do until all packages installed.     */
/*--------------------------------------------*/
var doWhile = function()
  {
  if (name = names.shift())
    doWhile0();
  }

var doWhile0 = function()
  {
  /*----------------------------------------------*/
  /* Installed package specification comes from   */
  /* 'from' field of installed packages. Required */
  /* specification comes from the packages list.  */
  /*----------------------------------------------*/
  var current  = (installed[name] || {}).from;
  var required =   packages[name];

  /*---------------------------------------*/
  /* Install the package if not installed. */
  /*---------------------------------------*/
  if (!current)
    runCommand('npm install -g '+required, doWhile1);

  /*------------------------------------*/
  /* If the installed version does not  */
  /* match, uninstall and then install. */
  /*------------------------------------*/
  else if (current != required)
    {
    delete installed[name];
    runCommand('npm remove -g '+name, function() 
      {
      runCommand('npm remove '+name, doWhile0);
      });
    }

  /*------------------------------------*/
  /* Skip package if already installed. */
  /*------------------------------------*/
  else
    doWhile1();
  };

var doWhile1 = function()
  {
  /*-------------------------------------------------------*/
  /* Create link to global package from local environment. */
  /*-------------------------------------------------------*/
  if (doLinks && !fs.existsSync(path.join('node_modules', name)))
    runCommand('npm link '+name, doWhile);
  else
    doWhile();
  };

Now if I want to update a global tool for our developers, I update the "packages" object and check in the new script. My developers check it out and either run it with "node npm-setup.js" or by "npm install" from any of the products under development to update the global environment. The whole thing takes 5 minutes.

In addition, to configure the environment for the a new developer, they must first only install NodeJS and GIT for Windows, reboot their computer, check out the "Shared Files" folder and any products under development, and start working.

The "package.json" for the .NET product calls this script prior to install:

{ 
"name"                    : "Books",
"description"             : "Node (npm) configuration for Books Database Web Application Tools",
"version"                 : "2.1.1",
"private"                 : true,
"scripts":
  {
  "preinstall"            : "node ../../SharedFiles/npm-setup.js links",
  "postinstall"           : "bower install"
  },
"dependencies": {}
}

Notes

  • Note the script reference requires forward slashes even in a Windows environment.

  • "npm ls" will give "npm ERR! extraneous:" messages for all packages locally linked because they are not listed in the "package.json" "dependencies".

Edit 1/29/16

The updated npm-setup.js script above has been modified as follows:

  • Package "version" in var packages is now the "package" value passed to npm install on the command line. This was changed to allow for installing packages from somewhere other than the registered repository.

  • If the package is already installed but is not the one requested, the existing package is removed and the correct one installed.

  • For reasons unknown, npm will periodically throw an EBUSY error (-4082) when performing an install or link. This error is trapped and the command re-executed. The error rarely happens a second time and seems to always clear up.

How to choose multiple files using File Upload Control?

You can try below code:

 Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
    Try
        Dim j As Integer = 0
        Dim hfc As HttpFileCollection = Request.Files
        Dim PathName As String
        For i As Integer = 0 To hfc.Count - 1
            Dim hpf As HttpPostedFile = hfc(i)

            If hpf.ContentLength > 0 Then
                hpf.SaveAs(Server.MapPath("~/E:\") & System.IO.Path.GetFileName(hpf.FileName))
                PathName = Server.MapPath(hpf.FileName)

                If j < hfc.Count Then
                    Dim strConnString As String = ConfigurationManager.ConnectionStrings("conString").ConnectionString
                    Dim sqlquery As String
                    sqlquery = "Insert_proc"
                    Dim con As New SqlConnection(strConnString)
                    Dim cmd As New SqlCommand(sqlquery, con)

                    cmd.CommandType = CommandType.StoredProcedure

                    cmd.Parameters.Add("@FilePath", SqlDbType.VarChar).Value = PathName
                    j = j + 1

                    Try
                        con.Open()
                        cmd.ExecuteNonQuery()


                    Catch ex As Exception
                        Throw ex
                    Finally
                        con.Close()
                        con.Dispose()

                    End Try
                    If j = hfc.Count Then
                        Exit Sub
                    End If
                End If
            End If
        Next

    Catch generatedExceptionName As Exception

        Throw
    End Try
End Sub

How to delete/unset the properties of a javascript object?

simply use delete, but be aware that you should read fully what the effects are of using this:

 delete object.index; //true
 object.index; //undefined

but if I was to use like so:

var x = 1; //1
delete x; //false
x; //1

but if you do wish to delete variables in the global namespace, you can use it's global object such as window, or using this in the outermost scope i.e

var a = 'b';
delete a; //false
delete window.a; //true
delete this.a; //true

http://perfectionkills.com/understanding-delete/

another fact is that using delete on an array will not remove the index but only set the value to undefined, meaning in certain control structures such as for loops, you will still iterate over that entity, when it comes to array's you should use splice which is a prototype of the array object.

Example Array:

var myCars=new Array();
myCars[0]="Saab";
myCars[1]="Volvo";
myCars[2]="BMW";

if I was to do:

delete myCars[1];

the resulting array would be:

["Saab", undefined, "BMW"]

but using splice like so:

myCars.splice(1,1);

would result in:

["Saab", "BMW"]

Is there any option to limit mongodb memory usage?

Adding to the top voted answer, in case you are on a low memory machine and want to configure the wiredTigerCache in MBs instead of whole number GBs, use this -

storage:
 wiredTiger:
  engineConfig:
    configString : cache_size=345M

Source - https://jira.mongodb.org/browse/SERVER-22274

Spring Boot Remove Whitelabel Error Page

I had a similar issue WhiteLabel Error message on my Angular SPA whenever I did a refresh.

The fix was to create a controller that implements ErrorController but instead of returning a String, I had to return a ModelAndView object that forwards to /

@CrossOrigin
@RestController
public class IndexController implements ErrorController {
    
    private static final String PATH = "/error";
    
    @RequestMapping(value = PATH)
    public ModelAndView saveLeadQuery() {           
        return new ModelAndView("forward:/");
    }

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

BeanFactory vs ApplicationContext

do use BeanFactory for non-web applications because it supports only Singleton and Prototype bean-scopes.

While ApplicationContext container does support all the bean-scopes so you should use it for web applications.

Class file for com.google.android.gms.internal.zzaja not found

I solved this exact problem today and stumbled onto this unanswered question by chance during the process.

First, ensure you've properly setup Firebase for Android as documented here: https://firebase.google.com/docs/android/setup. Then, make sure you are compiling the latest version of the Firebase APIs (9.2.0) and the Google Play Services APIs (9.2.0) that you are using. My gradle dependencies look something like this:

dependencies {
    ...
    compile 'com.google.android.gms:play-services-location:9.2.0'
    compile 'com.google.firebase:firebase-core:9.2.0'
    compile 'com.google.firebase:firebase-auth:9.2.0'
    compile 'com.google.firebase:firebase-messaging:9.2.0'
}

Hope this helps!

Detecting an undefined object property

There are a few little helpers in the Lodash library:

isUndefined - to check if value is undefined.

_.isUndefined(undefined) // => true
_.isUndefined(null) // => false

has - to check if object contains a property

const object = { 'a': { 'b': 2 } }

_.has(object, 'a.b') // => true
_.has(object, 'a.c') // => false

How to remove a package in sublime text 2

If you installed with package control, search for "Package Control: Remove Package" in the command palette (accessed with Ctrl+Shift+P). Otherwise you can just remove the Emmet directory.

If you wish to use a custom caption to access commands, create Default.sublime-commands in your User folder. Then insert something similar to the following.

[
    {
        "caption": "Package Control: Uninstall Package",
        "command": "remove_package"
    }
]

Of course, you can customize the command and caption as you see fit.

Replace whole line containing a string using Sed

cat find_replace | while read pattern replacement ; do
sed -i "/${pattern}/c ${replacement}" file    
done 

find_replace file contains 2 columns, c1 with pattern to match, c2 with replacement, the sed loop replaces each line conatining one of the pattern of variable 1

Which Java library provides base64 encoding/decoding?

Java 9

Use the Java 8 solution. Note DatatypeConverter can still be used, but it is now within the java.xml.bind module which will need to be included.

module org.example.foo {
    requires java.xml.bind;
}

Java 8

Java 8 now provides java.util.Base64 for encoding and decoding base64.

Encoding

byte[] message = "hello world".getBytes(StandardCharsets.UTF_8);
String encoded = Base64.getEncoder().encodeToString(message);
System.out.println(encoded);
// => aGVsbG8gd29ybGQ=

Decoding

byte[] decoded = Base64.getDecoder().decode("aGVsbG8gd29ybGQ=");
System.out.println(new String(decoded, StandardCharsets.UTF_8));
// => hello world

Java 6 and 7

Since Java 6 the lesser known class javax.xml.bind.DatatypeConverter can be used. This is part of the JRE, no extra libraries required.

Encoding

byte[] message = "hello world".getBytes("UTF-8");
String encoded = DatatypeConverter.printBase64Binary(message);
System.out.println(encoded);
// => aGVsbG8gd29ybGQ=  

Decoding

byte[] decoded = DatatypeConverter.parseBase64Binary("aGVsbG8gd29ybGQ=");
System.out.println(new String(decoded, "UTF-8"));
// => hello world

Delete an element in a JSON object

Let's assume you want to overwrite the same file:

import json

with open('data.json', 'r') as data_file:
    data = json.load(data_file)

for element in data:
    element.pop('hours', None)

with open('data.json', 'w') as data_file:
    data = json.dump(data, data_file)

dict.pop(<key>, not_found=None) is probably what you where looking for, if I understood your requirements. Because it will remove the hours key if present and will not fail if not present.

However I am not sure I understand why it makes a difference to you whether the hours key contains some days or not, because you just want to get rid of the whole key / value pair, right?

Now, if you really want to use del instead of pop, here is how you could make your code work:

import json

with open('data.json') as data_file:
    data = json.load(data_file)

for element in data:
    if 'hours' in element:
        del element['hours']

with open('data.json', 'w') as data_file:
    data = json.dump(data, data_file)

EDIT So, as you can see, I added the code to write the data back to the file. If you want to write it to another file, just change the filename in the second open statement.

I had to change the indentation, as you might have noticed, so that the file has been closed during the data cleanup phase and can be overwritten at the end.

with is what is called a context manager, whatever it provides (here the data_file file descriptor) is available ONLY within that context. It means that as soon as the indentation of the with block ends, the file gets closed and the context ends, along with the file descriptor which becomes invalid / obsolete.

Without doing this, you wouldn't be able to open the file in write mode and get a new file descriptor to write into.

I hope it's clear enough...

SECOND EDIT

This time, it seems clear that you need to do this:

with open('dest_file.json', 'w') as dest_file:
    with open('source_file.json', 'r') as source_file:
        for line in source_file:
            element = json.loads(line.strip())
            if 'hours' in element:
                del element['hours']
            dest_file.write(json.dumps(element))

Twig: in_array or similar possible within if statement?

Just to clear some things up here. The answer that was accepted does not do the same as PHP in_array.

To do the same as PHP in_array use following expression:

{% if myVar in myArray %}

If you want to negate this you should use this:

{% if myVar not in myArray %}

Get Country of IP Address with PHP

If you need to have a good and updated database, for having more performance and not requesting external services from your website, here there is a good place to download updated and accurate databases.

I'm recommending this because in my experience it was working excellent even including city and country location for my IP which most of other databases/apis failed to include/report my location except this service which directed me to this database.
(My ip location was from "Rasht" City in "Iran" when I was testing and the ip was: 2.187.21.235 equal to 45815275)

Therefore I recommend to use these services if you're unsure about which service is more accurate:

Database: http://lite.ip2location.com/databases

API Service: http://ipinfodb.com/ip_location_api.php

Adding an image to a PDF using iTextSharp and scale it properly

Personally, I use something close from fubo's solution and it works well:

image.ScaleToFit(document.PageSize);
image.SetAbsolutePosition(0,0);

Bash: If/Else statement in one line

There is no need to explicitly check $?. Just do:

ps aux | grep some_proces[s] > /tmp/test.txt && echo 1 || echo 0 

Note that this relies on echo not failing, which is certainly not guaranteed. A more reliable way to write this is:

if ps aux | grep some_proces[s] > /tmp/test.txt; then echo 1; else echo 0; fi

Excel formula to display ONLY month and year?

Try the formula

=TEXT(TODAY(),"MMYYYY")

Setting values of input fields with Angular 6

You should use the following:

       <td><input id="priceInput-{{orderLine.id}}" type="number" [(ngModel)]="orderLine.price"></td>

You will need to add the FormsModule to your app.module in the inputs section as follows:

import { FormsModule } from '@angular/forms';

@NgModule({
  declarations: [
    ...
  ],
  imports: [
    BrowserModule,
    FormsModule
  ],
  ..

The use of the brackets around the ngModel are as follows:

  • The [] show that it is taking an input from your TS file. This input should be a public member variable. A one way binding from TS to HTML.

  • The () show that it is taking output from your HTML file to a variable in the TS file. A one way binding from HTML to TS.

  • The [()] are both (e.g. a two way binding)

See here for more information: https://angular.io/guide/template-syntax

I would also suggest replacing id="priceInput-{{orderLine.id}}" with something like this [id]="getElementId(orderLine)" where getElementId(orderLine) returns the element Id in the TS file and can be used anywere you need to reference the element (to avoid simple bugs like calling it priceInput1 in one place and priceInput-1 in another. (if you still need to access the input by it's Id somewhere else)

On delete cascade with doctrine2

Here is simple example. A contact has one to many associated phone numbers. When a contact is deleted, I want all its associated phone numbers to also be deleted, so I use ON DELETE CASCADE. The one-to-many/many-to-one relationship is implemented with by the foreign key in the phone_numbers.

CREATE TABLE contacts
 (contact_id BIGINT AUTO_INCREMENT NOT NULL,
 name VARCHAR(75) NOT NULL,
 PRIMARY KEY(contact_id)) ENGINE = InnoDB;

CREATE TABLE phone_numbers
 (phone_id BIGINT AUTO_INCREMENT NOT NULL,
  phone_number CHAR(10) NOT NULL,
 contact_id BIGINT NOT NULL,
 PRIMARY KEY(phone_id),
 UNIQUE(phone_number)) ENGINE = InnoDB;

ALTER TABLE phone_numbers ADD FOREIGN KEY (contact_id) REFERENCES \
contacts(contact_id) ) ON DELETE CASCADE;

By adding "ON DELETE CASCADE" to the foreign key constraint, phone_numbers will automatically be deleted when their associated contact is deleted.

INSERT INTO table contacts(name) VALUES('Robert Smith');
INSERT INTO table phone_numbers(phone_number, contact_id) VALUES('8963333333', 1);
INSERT INTO table phone_numbers(phone_number, contact_id) VALUES('8964444444', 1);

Now when a row in the contacts table is deleted, all its associated phone_numbers rows will automatically be deleted.

DELETE TABLE contacts as c WHERE c.id=1; /* delete cascades to phone_numbers */

To achieve the same thing in Doctrine, to get the same DB-level "ON DELETE CASCADE" behavoir, you configure the @JoinColumn with the onDelete="CASCADE" option.

<?php
namespace Entities;

use Doctrine\Common\Collections\ArrayCollection;

/**
 * @Entity
 * @Table(name="contacts")
 */
class Contact 
{

    /**
     *  @Id
     *  @Column(type="integer", name="contact_id") 
     *  @GeneratedValue
     */
    protected $id;  

    /** 
     * @Column(type="string", length="75", unique="true") 
     */ 
    protected $name; 

    /** 
     * @OneToMany(targetEntity="Phonenumber", mappedBy="contact")
     */ 
    protected $phonenumbers; 

    public function __construct($name=null)
    {
        $this->phonenumbers = new ArrayCollection();

        if (!is_null($name)) {

            $this->name = $name;
        }
    }

    public function getId()
    {
        return $this->id;
    }

    public function setName($name)
    {
        $this->name = $name;
    }

    public function addPhonenumber(Phonenumber $p)
    {
        if (!$this->phonenumbers->contains($p)) {

            $this->phonenumbers[] = $p;
            $p->setContact($this);
        }
    }

    public function removePhonenumber(Phonenumber $p)
    {
        $this->phonenumbers->remove($p);
    }
}

<?php
namespace Entities;

/**
 * @Entity
 * @Table(name="phonenumbers")
 */
class Phonenumber 
{

    /**
    * @Id
    * @Column(type="integer", name="phone_id") 
    * @GeneratedValue
    */
    protected $id; 

    /**
     * @Column(type="string", length="10", unique="true") 
     */  
    protected $number;

    /** 
     * @ManyToOne(targetEntity="Contact", inversedBy="phonenumbers")
     * @JoinColumn(name="contact_id", referencedColumnName="contact_id", onDelete="CASCADE")
     */ 
    protected $contact; 

    public function __construct($number=null)
    {
        if (!is_null($number)) {

            $this->number = $number;
        }
    }

    public function setPhonenumber($number)
    {
        $this->number = $number;
    }

    public function setContact(Contact $c)
    {
        $this->contact = $c;
    }
} 
?>

<?php

$em = \Doctrine\ORM\EntityManager::create($connectionOptions, $config);

$contact = new Contact("John Doe"); 

$phone1 = new Phonenumber("8173333333");
$phone2 = new Phonenumber("8174444444");
$em->persist($phone1);
$em->persist($phone2);
$contact->addPhonenumber($phone1); 
$contact->addPhonenumber($phone2); 

$em->persist($contact);
try {

    $em->flush();
} catch(Exception $e) {

    $m = $e->getMessage();
    echo $m . "<br />\n";
}

If you now do

# doctrine orm:schema-tool:create --dump-sql

you will see that the same SQL will be generated as in the first, raw-SQL example

Renaming Columns in an SQL SELECT Statement

You can alias the column names one by one, like so

SELECT col1 as `MyNameForCol1`, col2 as `MyNameForCol2` 
FROM `foobar`

Edit You can access INFORMATION_SCHEMA.COLUMNS directly to mangle a new alias like so. However, how you fit this into a query is beyond my MySql skills :(

select CONCAT('Foobar_', COLUMN_NAME)
from INFORMATION_SCHEMA.COLUMNS 
where TABLE_NAME = 'Foobar'

Using Java 8's Optional with Stream::flatMap

Java 9

Optional.stream has been added to JDK 9. This enables you to do the following, without the need of any helper method:

Optional<Other> result =
    things.stream()
          .map(this::resolve)
          .flatMap(Optional::stream)
          .findFirst();

Java 8

Yes, this was a small hole in the API, in that it's somewhat inconvenient to turn an Optional<T> into a zero-or-one length Stream<T>. You could do this:

Optional<Other> result =
    things.stream()
          .map(this::resolve)
          .flatMap(o -> o.isPresent() ? Stream.of(o.get()) : Stream.empty())
          .findFirst();

Having the ternary operator inside the flatMap is a bit cumbersome, though, so it might be better to write a little helper function to do this:

/**
 * Turns an Optional<T> into a Stream<T> of length zero or one depending upon
 * whether a value is present.
 */
static <T> Stream<T> streamopt(Optional<T> opt) {
    if (opt.isPresent())
        return Stream.of(opt.get());
    else
        return Stream.empty();
}

Optional<Other> result =
    things.stream()
          .flatMap(t -> streamopt(resolve(t)))
          .findFirst();

Here, I've inlined the call to resolve() instead of having a separate map() operation, but this is a matter of taste.

Can we use JSch for SSH key-based communication?

It is possible. Have a look at JSch.addIdentity(...)

This allows you to use key either as byte array or to read it from file.

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.Session;

public class UserAuthPubKey {
    public static void main(String[] arg) {
        try {
            JSch jsch = new JSch();

            String user = "tjill";
            String host = "192.18.0.246";
            int port = 10022;
            String privateKey = ".ssh/id_rsa";

            jsch.addIdentity(privateKey);
            System.out.println("identity added ");

            Session session = jsch.getSession(user, host, port);
            System.out.println("session created.");

            // disabling StrictHostKeyChecking may help to make connection but makes it insecure
            // see http://stackoverflow.com/questions/30178936/jsch-sftp-security-with-session-setconfigstricthostkeychecking-no
            // 
            // java.util.Properties config = new java.util.Properties();
            // config.put("StrictHostKeyChecking", "no");
            // session.setConfig(config);

            session.connect();
            System.out.println("session connected.....");

            Channel channel = session.openChannel("sftp");
            channel.setInputStream(System.in);
            channel.setOutputStream(System.out);
            channel.connect();
            System.out.println("shell channel connected....");

            ChannelSftp c = (ChannelSftp) channel;

            String fileName = "test.txt";
            c.put(fileName, "./in/");
            c.exit();
            System.out.println("done");

        } catch (Exception e) {
            System.err.println(e);
        }
    }
}

Setting a minimum/maximum character count for any character using a regular expression

If you want to set Min 1 count and no Max length,

^.{1,}$

Python initializing a list of lists

The problem is that they're all the same exact list in memory. When you use the [x]*n syntax, what you get is a list of n many x objects, but they're all references to the same object. They're not distinct instances, rather, just n references to the same instance.

To make a list of 3 different lists, do this:

x = [[] for i in range(3)]

This gives you 3 separate instances of [], which is what you want

[[]]*n is similar to

l = []
x = []
for i in range(n):
    x.append(l)

While [[] for i in range(3)] is similar to:

x = []
for i in range(n):
    x.append([])   # appending a new list!

In [20]: x = [[]] * 4

In [21]: [id(i) for i in x]
Out[21]: [164363948, 164363948, 164363948, 164363948] # same id()'s for each list,i.e same object


In [22]: x=[[] for i in range(4)]

In [23]: [id(i) for i in x]
Out[23]: [164382060, 164364140, 164363628, 164381292] #different id(), i.e unique objects this time

versionCode vs versionName in Android Manifest

android:versionCode — An integer value that represents the version of the application code, relative to other versions.

The value is an integer so that other applications can programmatically evaluate it, for example to check an upgrade or downgrade relationship. You can set the value to any integer you want, however you should make sure that each successive release of your application uses a greater value. The system does not enforce this behavior, but increasing the value with successive releases is normative.

android:versionName — A string value that represents the release version of the application code, as it should be shown to users.

The value is a string so that you can describe the application version as a .. string, or as any other type of absolute or relative version identifier.

As with android:versionCode, the system does not use this value for any internal purpose, other than to enable applications to display it to users. Publishing services may also extract the android:versionName value for display to users.

Typically, you would release the first version of your application with versionCode set to 1, then monotonically increase the value with each release, regardless whether the release constitutes a major or minor release. This means that the android:versionCode value does not necessarily have a strong resemblance to the application release version that is visible to the user (see android:versionName, below). Applications and publishing services should not display this version value to users.

Up, Down, Left and Right arrow keys do not trigger KeyDown event

protected override bool IsInputKey(Keys keyData)
{
    if (((keyData & Keys.Up) == Keys.Up)
        || ((keyData & Keys.Down) == Keys.Down)
        || ((keyData & Keys.Left) == Keys.Left)
        || ((keyData & Keys.Right) == Keys.Right))
        return true;
    else
        return base.IsInputKey(keyData);
}

Deploy a project using Git push

dont install git on a server or copy the .git folder there. to update a server from a git clone you can use following command:

git ls-files -z | rsync --files-from - --copy-links -av0 . [email protected]:/var/www/project

you might have to delete files which got removed from the project.

this copies all the checked in files. rsync uses ssh which is installed on a server anyways.

the less software you have installed on a server the more secure he is and the easier it is to manage it's configuration and document it. there is also no need to keep a complete git clone on the server. it only makes it more complex to secure everything properly.

Jquery find nearest matching element

Get the .column parent of the this element, get its previous sibling, then find any input there:

$(this).closest(".column").prev().find("input:first").val();

Demo: http://jsfiddle.net/aWhtP/

What is the use of "assert"?

As summarized concisely on the C2 Wiki:

An assertion is a boolean expression at a specific point in a program which will be true unless there is a bug in the program.

You can use an assert statement to document your understanding of the code at a particular program point. For example, you can document assumptions or guarantees about inputs (preconditions), program state (invariants), or outputs (postconditions).

Should your assertion ever fail, this is an alert for you (or your successor) that your understanding of the program was wrong when you wrote it, and that it likely contains a bug.

For more information, John Regehr has a wonderful blog post on the Use of Assertions, which applies to the Python assert statement as well.

How do I turn a C# object into a JSON string in .NET?

Serializer

 public static void WriteToJsonFile<T>(string filePath, T objectToWrite, bool append = false) where T : new()
{
        var contentsToWriteToFile = JsonConvert.SerializeObject(objectToWrite, new JsonSerializerSettings
        {
            Formatting = Formatting.Indented,
        });
        using (var writer = new StreamWriter(filePath, append))
        {
            writer.Write(contentsToWriteToFile);
        }
}

Object

namespace MyConfig
{
    public class AppConfigurationSettings
    {
        public AppConfigurationSettings()
        {
            /* initialize the object if you want to output a new document
             * for use as a template or default settings possibly when 
             * an app is started.
             */
            if (AppSettings == null) { AppSettings=new AppSettings();}
        }

        public AppSettings AppSettings { get; set; }
    }

    public class AppSettings
    {
        public bool DebugMode { get; set; } = false;
    }
}

Implementation

var jsonObject = new AppConfigurationSettings();
WriteToJsonFile<AppConfigurationSettings>(file.FullName, jsonObject);

Output

{
  "AppSettings": {
    "DebugMode": false
  }
}

How to create user for a db in postgresql?

From CLI:

$ su - postgres 
$ psql template1
template1=# CREATE USER tester WITH PASSWORD 'test_password';
template1=# GRANT ALL PRIVILEGES ON DATABASE "test_database" to tester;
template1=# \q

PHP (as tested on localhost, it works as expected):

  $connString = 'port=5432 dbname=test_database user=tester password=test_password';
  $connHandler = pg_connect($connString);
  echo 'Connected to '.pg_dbname($connHandler);

How to get option text value using AngularJS?

The best way is to use the ng-options directive on the select element.

Controller

function Ctrl($scope) {
  // sort options
  $scope.products = [{
    value: 'prod_1',
    label: 'Product 1'
  }, {
    value: 'prod_2',
    label: 'Product 2'
  }];   
}

HTML

<select ng-model="selected_product" 
        ng-options="product as product.label for product in products">           
</select>

This will bind the selected product object to the ng-model property - selected_product. After that you can use this:

<p>Ordered by: {{selected_product.label}}</p>

jsFiddle: http://jsfiddle.net/bmleite/2qfSB/

What's the difference between Sender, From and Return-Path?

The official RFC which defines this specification could be found here:

http://tools.ietf.org/html/rfc4021#section-2.1.2 (look at paragraph 2.1.2. and the following)

2.1.2. Header Field: From

Description:  
    Mailbox of message author  
[...]  
Related information:
    Specifies the author(s) of the message; that is, the mailbox(es)
    of the person(s) or system(s) responsible for the writing of the
    message. Defined as standard by RFC 822.

2.1.3. Header Field: Sender

Description:  
    Mailbox of message sender  
[...]  
Related information:
    Specifies the mailbox of the agent responsible for the actual
    transmission of the message.  Defined as standard by RFC 822.

2.1.22. Header Field: Return-Path

Description:
    Message return path
[...]  
Related information:
    Return path for message response diagnostics. See also RFC 2821
    [17]. Defined as standard by RFC 822.

Angular2 RC6: '<component> is not a known element'

I had the same problem and i fixed by adding the component (MyComponentToUse) in exports array in the module where my component was declared (ModuleLower). Then i import ModuleLower in ModuleHigher, so i can reuse now my component ( MyComponentToUse) in the ModuleLower and the ModuleHigher

            @NgModule({
              declarations: [
                MyComponentToUse
              ],
              exports: [
                MyComponentToUse
              ]
            })
            export class ModuleLower {}


            @NgModule({
              imports: [
                ModuleLower
              ]
            })
            export class ModuleHigher {} 

Excel- compare two cell from different sheet, if true copy value from other cell

In your destination field you want to use VLOOKUP like so:

=VLOOKUP(Sheet1!A1:A100,Sheet2!A1:F100,6,FALSE)

VLOOKUP Arguments:

  1. The set fields you want to lookup.
  2. The table range you want to lookup up your value against. The first column of your defined table should be the column you want compared against your lookup field. The table range should also contain the value you want to display (Column F).
  3. This defines what field you want to display upon a match.
  4. FALSE tells VLOOKUP to do an exact match.

Is there a way to compile node.js source files?

Now this may include more than you need (and may not even work for command line applications in a non-graphical environment, I don't know), but there is nw.js. It's Blink (i.e. Chromium/Webkit) + io.js (i.e. Node.js).

You can use node-webkit-builder to build native executable binaries for Linux, OS X and Windows.

If you want a GUI, that's a huge plus. You can build one with web technologies. If you don't, specify "node-main" in the package.json (and probably "window": {"show": false} although maybe it works to just have a node-main and not a main)

I haven't tried to use it in exactly this way, just throwing it out there as a possibility. I can say it's certainly not an ideal solution for non-graphical Node.js applications.

When to use AtomicReference in Java?

I won't talk much. Already my respected fellow friends have given their valuable input. The full fledged running code at the last of this blog should remove any confusion. It's about a movie seat booking small program in multi-threaded scenario.

Some important elementary facts are as follows. 1> Different threads can only contend for instance and static member variables in the heap space. 2> Volatile read or write are completely atomic and serialized/happens before and only done from memory. By saying this I mean that any read will follow the previous write in memory. And any write will follow the previous read from memory. So any thread working with a volatile will always see the most up-to-date value. AtomicReference uses this property of volatile.

Following are some of the source code of AtomicReference. AtomicReference refers to an object reference. This reference is a volatile member variable in the AtomicReference instance as below.

private volatile V value;

get() simply returns the latest value of the variable (as volatiles do in a "happens before" manner).

public final V get()

Following is the most important method of AtomicReference.

public final boolean  compareAndSet(V expect, V update) {
        return unsafe.compareAndSwapObject(this, valueOffset, expect, update);
}

The compareAndSet(expect,update) method calls the compareAndSwapObject() method of the unsafe class of Java. This method call of unsafe invokes the native call, which invokes a single instruction to the processor. "expect" and "update" each reference an object.

If and only if the AtomicReference instance member variable "value" refers to the same object is referred to by "expect", "update" is assigned to this instance variable now, and "true" is returned. Or else, false is returned. The whole thing is done atomically. No other thread can intercept in between. As this is a single processor operation (magic of modern computer architecture), it's often faster than using a synchronized block. But remember that when multiple variables need to be updated atomically, AtomicReference won't help.

I would like to add a full fledged running code, which can be run in eclipse. It would clear many confusion. Here 22 users (MyTh threads) are trying to book 20 seats. Following is the code snippet followed by the full code.

Code snippet where 22 users are trying to book 20 seats.

for (int i = 0; i < 20; i++) {// 20 seats
            seats.add(new AtomicReference<Integer>());
        }
        Thread[] ths = new Thread[22];// 22 users
        for (int i = 0; i < ths.length; i++) {
            ths[i] = new MyTh(seats, i);
            ths[i].start();
        }

Following is the full running code.

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;

public class Solution {

    static List<AtomicReference<Integer>> seats;// Movie seats numbered as per
                                                // list index

    public static void main(String[] args) throws InterruptedException {
        // TODO Auto-generated method stub
        seats = new ArrayList<>();
        for (int i = 0; i < 20; i++) {// 20 seats
            seats.add(new AtomicReference<Integer>());
        }
        Thread[] ths = new Thread[22];// 22 users
        for (int i = 0; i < ths.length; i++) {
            ths[i] = new MyTh(seats, i);
            ths[i].start();
        }
        for (Thread t : ths) {
            t.join();
        }
        for (AtomicReference<Integer> seat : seats) {
            System.out.print(" " + seat.get());
        }
    }

    /**
     * id is the id of the user
     * 
     * @author sankbane
     *
     */
    static class MyTh extends Thread {// each thread is a user
        static AtomicInteger full = new AtomicInteger(0);
        List<AtomicReference<Integer>> l;//seats
        int id;//id of the users
        int seats;

        public MyTh(List<AtomicReference<Integer>> list, int userId) {
            l = list;
            this.id = userId;
            seats = list.size();
        }

        @Override
        public void run() {
            boolean reserved = false;
            try {
                while (!reserved && full.get() < seats) {
                    Thread.sleep(50);
                    int r = ThreadLocalRandom.current().nextInt(0, seats);// excludes
                                                                            // seats
                                                                            //
                    AtomicReference<Integer> el = l.get(r);
                    reserved = el.compareAndSet(null, id);// null means no user
                                                            // has reserved this
                                                            // seat
                    if (reserved)
                        full.getAndIncrement();
                }
                if (!reserved && full.get() == seats)
                    System.out.println("user " + id + " did not get a seat");
            } catch (InterruptedException ie) {
                // log it
            }
        }
    }

}    

Browser: Identifier X has already been declared

The problem solved when I don't use any declaration like var, let or const

Using Spring 3 autowire in a standalone Java application

Spring works in standalone application. You are using the wrong way to create a spring bean. The correct way to do it like this:

@Component
public class Main {

    public static void main(String[] args) {
        ApplicationContext context = 
            new ClassPathXmlApplicationContext("META-INF/config.xml");

        Main p = context.getBean(Main.class);
        p.start(args);
    }

    @Autowired
    private MyBean myBean;
    private void start(String[] args) {
        System.out.println("my beans method: " + myBean.getStr());
    }
}

@Service 
public class MyBean {
    public String getStr() {
        return "string";
    }
}

In the first case (the one in the question), you are creating the object by yourself, rather than getting it from the Spring context. So Spring does not get a chance to Autowire the dependencies (which causes the NullPointerException).

In the second case (the one in this answer), you get the bean from the Spring context and hence it is Spring managed and Spring takes care of autowiring.

What is a word boundary in regex, does \b match hyphen '-'?

A word boundary, in most regex dialects, is a position between \w and \W (non-word char), or at the beginning or end of a string if it begins or ends (respectively) with a word character ([0-9A-Za-z_]).

So, in the string "-12", it would match before the 1 or after the 2. The dash is not a word character.

unknown type name 'uint8_t', MinGW

Try including stdint.h or inttypes.h.

Show/hide image with JavaScript

You can do this with jquery just visit http://jquery.com/ to get the link then do something like this

<a id="show_image">Show Image</a>
<img id="my_images" style="display:none" src="http://myimages.com/img.png">

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script>
   $(document).ready(function(){
      $('#show_image').on("click", function(){
         $('#my_images').show('slow');
      });
   });
</script>

or if you would like the link to turn the image on and off do this

<a id="show_image">Show Image</a>
<img id="my_images" style="display:none;" src="http://myimages.com/img.png">

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script>
   $(document).ready(function(){
      $('#show_image').on("click", function(){
         $('#my_images').toggle();
      });
   });
</script>

counting the number of lines in a text file

I think your question is, "why am I getting one more line than there is in the file?"

Imagine a file:

line 1
line 2
line 3

The file may be represented in ASCII like this:

line 1\nline 2\nline 3\n

(Where \n is byte 0x10.)

Now let's see what happens before and after each getline call:

Before 1: line 1\nline 2\nline 3\n
  Stream: ^
After 1:  line 1\nline 2\nline 3\n
  Stream:         ^

Before 2: line 1\nline 2\nline 3\n
  Stream:         ^
After 2:  line 1\nline 2\nline 3\n
  Stream:                 ^

Before 2: line 1\nline 2\nline 3\n
  Stream:                 ^
After 2:  line 1\nline 2\nline 3\n
  Stream:                         ^

Now, you'd think the stream would mark eof to indicate the end of the file, right? Nope! This is because getline sets eof if the end-of-file marker is reached "during it's operation". Because getline terminates when it reaches \n, the end-of-file marker isn't read, and eof isn't flagged. Thus, myfile.eof() returns false, and the loop goes through another iteration:

Before 3: line 1\nline 2\nline 3\n
  Stream:                         ^
After 3:  line 1\nline 2\nline 3\n
  Stream:                         ^ EOF

How do you fix this? Instead of checking for eof(), see if .peek() returns EOF:

while(myfile.peek() != EOF){
    getline ...

You can also check the return value of getline (implicitly casting to bool):

while(getline(myfile,line)){
    cout<< ...

How to escape strings in SQL Server using PHP?

function ms_escape_string($data) {
        if ( !isset($data) or empty($data) ) return '';
        if ( is_numeric($data) ) return $data;

        $non_displayables = array(
            '/%0[0-8bcef]/',            // url encoded 00-08, 11, 12, 14, 15
            '/%1[0-9a-f]/',             // url encoded 16-31
            '/[\x00-\x08]/',            // 00-08
            '/\x0b/',                   // 11
            '/\x0c/',                   // 12
            '/[\x0e-\x1f]/'             // 14-31
        );
        foreach ( $non_displayables as $regex )
            $data = preg_replace( $regex, '', $data );
        $data = str_replace("'", "''", $data );
        return $data;
    }

Some of the code here was ripped off from CodeIgniter. Works well and is a clean solution.

EDIT: There are plenty of issues with that code snippet above. Please don't use this without reading the comments to know what those are. Better yet, please don't use this at all. Parameterized queries are your friends: http://php.net/manual/en/pdo.prepared-statements.php

Description for event id from source cannot be found

Improving on the answer by @Alex, I suggest the following:

            using (EventLog eventLog = new EventLog("Application"))
            {
                //You cannot be sure if the current identity has permissions to register the event source.
                try
                {
                    if (System.Web.HttpRuntime.AppDomainAppId != null)
                    {
                        eventLog.Source = System.Web.HttpRuntime.AppDomainAppId;
                    }
                    else
                    {
                        eventLog.Source = Process.GetCurrentProcess().ProcessName;
                    }
                }
                catch (SecurityException)
                {
                    eventLog.Source = "Application";
                }

                eventLog.WriteEntry("Log message example", EventLogEntryType.Information, 1000);
            }

It is important here not to specify category parameter. If you do, and this is the same for the .NET Runtime so-called magic, the

The description for Event ID <...> from source <...> cannot be found.

is going to appear.

Check if a input box is empty

To auto check a checkbox if input field is not empty.

 <md-content>
            <md-checkbox ng-checked="myField.length"> Other </md-checkbox>
            <input  ng-model="myField" placeholder="Please Specify" type="text">
 </md-content>

XOR operation with two strings in java

Pay attention:

A Java char corresponds to a UTF-16 code unit, and in some cases two consecutive chars (a so-called surrogate pair) are needed for one real Unicode character (codepoint).

XORing two valid UTF-16 sequences (i.e. Java Strings char by char, or byte by byte after encoding to UTF-16) does not necessarily give you another valid UTF-16 string - you may have unpaired surrogates as a result. (It would still be a perfectly usable Java String, just the codepoint-concerning methods could get confused, and the ones that convert to other encodings for output and similar.)

The same is valid if you first convert your Strings to UTF-8 and then XOR these bytes - here you quite probably will end up with a byte sequence which is not valid UTF-8, if your Strings were not already both pure ASCII strings.

Even if you try to do it right and iterate over your two Strings by codepoint and try to XOR the codepoints, you can end up with codepoints outside the valid range (for example, U+FFFFF (plane 15) XOR U+10000 (plane 16) = U+1FFFFF (which would the last character of plane 31), way above the range of existing codepoints. And you could also end up this way with codepoints reserved for surrogates (= not valid ones).

If your strings only contain chars < 128, 256, 512, 1024, 2048, 4096, 8192, 16384, or 32768, then the (char-wise) XORed strings will be in the same range, and thus certainly not contain any surrogates. In the first two cases you could also encode your String as ASCII or Latin-1, respectively, and have the same XOR-result for the bytes. (You still can end up with control chars, which may be a problem for you.)


What I'm finally saying here: don't expect the result of encrypting Strings to be a valid string again - instead, simply store and transmit it as a byte[] (or a stream of bytes). (And yes, convert to UTF-8 before encrypting, and from UTF-8 after decrypting).

Regex that accepts only numbers (0-9) and NO characters

Your regex ^[0-9] matches anything beginning with a digit, including strings like "1A". To avoid a partial match, append a $ to the end:

^[0-9]*$

This accepts any number of digits, including none. To accept one or more digits, change the * to +. To accept exactly one digit, just remove the *.

UPDATE: You mixed up the arguments to IsMatch. The pattern should be the second argument, not the first:

if (!System.Text.RegularExpressions.Regex.IsMatch(textbox.Text, "^[0-9]*$"))

CAUTION: In JavaScript, \d is equivalent to [0-9], but in .NET, \d by default matches any Unicode decimal digit, including exotic fare like ? (Myanmar 2) and ? (N'Ko 9). Unless your app is prepared to deal with these characters, stick with [0-9] (or supply the RegexOptions.ECMAScript flag).

How to export a table dataframe in PySpark to csv?

How about this (in you don't want an one liner) ?

for row in df.collect():
    d = row.asDict()
    s = "%d\t%s\t%s\n" % (d["int_column"], d["string_column"], d["string_column"])
    f.write(s)

f is a opened file descriptor. Also the separator is a TAB char, but it's easy to change to whatever you want.

How to convert QString to std::string?

The simplest way would be QString::toStdString().

Using :: in C++

The :: are used to dereference scopes.

const int x = 5;

namespace foo {
  const int x = 0;
}

int bar() {
  int x = 1;
  return x;
}

struct Meh {
  static const int x = 2;
}

int main() {
  std::cout << x; // => 5
  {
    int x = 4;
    std::cout << x; // => 4
    std::cout << ::x; // => 5, this one looks for x outside the current scope
  }
  std::cout << Meh::x; // => 2, use the definition of x inside the scope of Meh
  std::cout << foo::x; // => 0, use the definition of x inside foo
  std::cout << bar(); // => 1, use the definition of x inside bar (returned by bar)
}

unrelated: cout and cin are not functions, but instances of stream objects.

EDIT fixed as Keine Lust suggested

How to convert string to binary?

You can access the code values for the characters in your string using the ord() built-in function. If you then need to format this in binary, the string.format() method will do the job.

a = "test"
print(' '.join(format(ord(x), 'b') for x in a))

(Thanks to Ashwini Chaudhary for posting that code snippet.)

While the above code works in Python 3, this matter gets more complicated if you're assuming any encoding other than UTF-8. In Python 2, strings are byte sequences, and ASCII encoding is assumed by default. In Python 3, strings are assumed to be Unicode, and there's a separate bytes type that acts more like a Python 2 string. If you wish to assume any encoding other than UTF-8, you'll need to specify the encoding.

In Python 3, then, you can do something like this:

a = "test"
a_bytes = bytes(a, "ascii")
print(' '.join(["{0:b}".format(x) for x in a_bytes]))

The differences between UTF-8 and ascii encoding won't be obvious for simple alphanumeric strings, but will become important if you're processing text that includes characters not in the ascii character set.

matplotlib set yaxis label size

If you are using the 'pylab' for interactive plotting you can set the labelsize at creation time with pylab.ylabel('Example', fontsize=40).

If you use pyplot programmatically you can either set the fontsize on creation with ax.set_ylabel('Example', fontsize=40) or afterwards with ax.yaxis.label.set_size(40).

Call to a member function on a non-object

It means that $objPage is not an instance of an object. Can we see the code you used to initialize the variable?

As you expect a specific object type, you can also make use of PHPs type-hinting featureDocs to get the error when your logic is violated:

function page_properties(PageAtrributes $objPortal) {    
    ...
    $objPage->set_page_title($myrow['title']);
}

This function will only accept PageAtrributes for the first parameter.

The project cannot be built until the build path errors are resolved.

This works for me: close the project then re-open it, this will force eclipse to see it as a fresh project and detects a correct build path.

Can't use SURF, SIFT in OpenCV

since I had already compiled opencv when I discovered this problem, all I had to do was (from my opencv build directory):

make opencv_nonfree
sudo make install

How Do I Take a Screen Shot of a UIView?

Swift 4 updated :

extension UIView {
   var screenShot: UIImage?  {
        if #available(iOS 10, *) {
            let renderer = UIGraphicsImageRenderer(bounds: self.bounds)
            return renderer.image { (context) in
                self.layer.render(in: context.cgContext)
            }
        } else {
            UIGraphicsBeginImageContextWithOptions(bounds.size, false, 5);
            if let _ = UIGraphicsGetCurrentContext() {
                drawHierarchy(in: bounds, afterScreenUpdates: true)
                let screenshot = UIGraphicsGetImageFromCurrentImageContext()
                UIGraphicsEndImageContext()
                return screenshot
            }
            return nil
        }
    }
}

How to extract the year from a Python datetime object?

If you want the year from a (unknown) datetime-object:

tijd = datetime.datetime(9999, 12, 31, 23, 59, 59)

>>> tijd.timetuple()
time.struct_time(tm_year=9999, tm_mon=12, tm_mday=31, tm_hour=23, tm_min=59, tm_sec=59, tm_wday=4, tm_yday=365, tm_isdst=-1)
>>> tijd.timetuple().tm_year
9999

SQL Server 2008 - Login failed. The login is from an untrusted domain and cannot be used with Windows authentication

I had this issue and it was because the machine running the application isnt trusted for delegation on the domain by active directory. If it is a .net app running under an application pool identity DOMAIN_application.environment for example.. the identity can't make calls out to SQL unless the machine is trusted.

500 Error on AppHarbor but downloaded build works on my machine

Just a wild guess: (not much to go on) but I have had similar problems when, for example, I was using the IIS rewrite module on my local machine (and it worked fine), but when I uploaded to a host that did not have that add-on module installed, I would get a 500 error with very little to go on - sounds similar. It drove me crazy trying to find it.

So make sure whatever options/addons that you might have and be using locally in IIS are also installed on the host.

Similarly, make sure you understand everything that is being referenced/used in your web.config - that is likely the problem area.

DateTime.TryParse issue with dates of yyyy-dd-MM format

If you give the user the opportunity to change the date/time format, then you'll have to create a corresponding format string to use for parsing. If you know the possible date formats (i.e. the user has to select from a list), then this is much easier because you can create those format strings at compile time.

If you let the user do free-format design of the date/time format, then you'll have to create the corresponding DateTime format strings at runtime.

How to align content of a div to the bottom

If you're not worried about legacy browsers use a flexbox.

The parent element needs its display type set to flex

div.parent {
  display: flex;
  height: 100%;
}

Then you set the child element's align-self to flex-end.

span.child {
  display: inline-block;
  align-self: flex-end;
}

Here's the resource I used to learn: http://css-tricks.com/snippets/css/a-guide-to-flexbox/

Installing a plain plugin jar in Eclipse 3.5

This is how you can go about it:

  1. Close Eclipse
  2. Download a jar plugin (let's assume its testNG.jar)
  3. Copy testNG.jar to a certain folder (say C:\Project\resources\plugins)
  4. In your Eclipse installation folder, there is a folder named dropins (could be C:\eclipse\dropins), create a .link file in that folder, (like plugins.link)
  5. Open this file with any text editor and enter this one line:
    path=C:/Project/resources/plugins
  6. Save the file and start Eclipse.

And you are good to go!

Please do not forget to change your backward slashes in your plugins folder path to forward slashes on step 5. I used to forget and it would take my time unnecessarily.

Message "Async callback was not invoked within the 5000 ms timeout specified by jest.setTimeout"

You can also get timeout errors based on silly typos. e.g This seemingly innocuous mistake:

describe('Something', () => {
  it('Should do something', () => {
    expect(1).toEqual(1)
  })

  it('Should do nothing', something_that_does_not_exist => {
    expect(1).toEqual(1)
  })
})

Produces the following error:

FAIL src/TestNothing.spec.js (5.427s)
  ? Something › Should do nothing

    Timeout - Async callback was not invoked within the 5000ms timeout specified by jest.setTimeout.
      
      at node_modules/jest-jasmine2/build/queue_runner.js:68:21
      at Timeout.callback [as _onTimeout] (node_modules/jsdom/lib/jsdom/browser/Window.js:678:19)

Whilst the code sample posted doesn't suffer from this it might be a cause of failures elsewhere. Also note that I'm not setting a timeout for anything anywhere - either here or in the config. The 5000ms is just the default setting.

Why am I getting "Thread was being aborted" in ASP.NET?

This error can be caused by trying to end a response more than once. As other answers already mentioned, there are various methods that will end a response (like Response.End, or Response.Redirect). If you call more than one in a row, you'll get this error.

I came across this error when I tried to use Response.End after using Response.TransmitFile which seems to end the response too.

When does Java's Thread.sleep throw InterruptedException?

Methods like sleep() and wait() of class Thread might throw an InterruptedException. This will happen if some other thread wanted to interrupt the thread that is waiting or sleeping.

How to use find command to find all files with extensions from list?

In supplement to @Dennis Williamson 's response above, if you want the same regex to be case-insensitive to the file extensions, use -iregex :

find /path/to -iregex ".*\.\(jpg\|gif\|png\|jpeg\)" > log

Cannot run Eclipse; JVM terminated. Exit code=13

I used the new Eclipse Installer. I didn't like the installation path and I changed it manually. After that, I got the exit code=13 message too.

There is a new property in the eclipse.ini file named -install. I just had to modify it with the new location, and that solved this issue.

In the new installer I selected D:/eclipse, but the IDE was installed at D:/eclipse/eclipse. So, I moved the folder manually. The next time I tried to open eclipse I got the exit error. Thus, I had to modify eclipse.ini and set the current location:

-install
D:/eclipse

Setting the focus to a text field

This is an easy one:

textField.setFocus();

How to call python script on excel vba?

Try this:

RetVal = Shell("<full path to python.exe> " & "<full path to your python script>")

Or if the python script is in the same folder as the workbook, then you can try :

RetVal = Shell("<full path to python.exe> " & ActiveWorkBook.Path & "\<python script name>")

All details within <> are to be given. <> - indicates changeable fields

I guess this should work. But then again, if your script is going to call other files which are in different folders, it can cause errors unless your script has properly handled it. Hope it helps.

MySQL Like multiple values

Or if you need to match only the beginning of words:

WHERE interests LIKE 'sports%' OR interests LIKE 'pub%'

you can use the regexp caret matches:

WHERE interests REGEXP '^sports|^pub'

https://www.regular-expressions.info/anchors.html

How to calculate the SVG Path for an arc (of a circle)

@opsb's answers is neat, but the center point is not accurate, moreover, as @Jithin noted, if the angle is 360, then nothing is drawn at all.

@Jithin fixed the 360 issue, but if you selected less than 360 degree, then you'll get a line closing the arc loop, which is not required.

I fixed that, and added some animation in the code below:

_x000D_
_x000D_
function myArc(cx, cy, radius, max){       _x000D_
       var circle = document.getElementById("arc");_x000D_
        var e = circle.getAttribute("d");_x000D_
        var d = " M "+ (cx + radius) + " " + cy;_x000D_
        var angle=0;_x000D_
        window.timer = window.setInterval(_x000D_
        function() {_x000D_
            var radians= angle * (Math.PI / 180);  // convert degree to radians_x000D_
            var x = cx + Math.cos(radians) * radius;  _x000D_
            var y = cy + Math.sin(radians) * radius;_x000D_
           _x000D_
            d += " L "+x + " " + y;_x000D_
            circle.setAttribute("d", d)_x000D_
            if(angle==max)window.clearInterval(window.timer);_x000D_
            angle++;_x000D_
        }_x000D_
      ,5)_x000D_
 }     _x000D_
_x000D_
  myArc(110, 110, 100, 360);_x000D_
    
_x000D_
<svg xmlns="http://www.w3.org/2000/svg" style="width:220; height:220;"> _x000D_
    <path d="" id="arc" fill="none" stroke="red" stroke-width="2" />_x000D_
</svg>
_x000D_
_x000D_
_x000D_

How to use GROUP BY to concatenate strings in SQL Server?

Let's get very simple:

SELECT stuff(
    (
    select ', ' + x from (SELECT 'xxx' x union select 'yyyy') tb 
    FOR XML PATH('')
    )
, 1, 2, '')

Replace this line:

select ', ' + x from (SELECT 'xxx' x union select 'yyyy') tb

With your query.

Git pushing to remote branch

First, let's note that git push "wants" two more arguments and will make them up automatically if you don't supply them. The basic command is therefore git push remote refspec.

The remote part is usually trivial as it's almost always just the word origin. The trickier part is the refspec. Most commonly, people write a branch name here: git push origin master, for instance. This uses your local branch to push to a branch of the same name1 on the remote, creating it if necessary. But it doesn't have to be just a branch name.

In particular, a refspec has two colon-separated parts. For git push, the part on the left identifies what to push,2 and the part on the right identifies the name to give to the remote. The part on the left in this case would be branch_name and the part on the right would be branch_name_test. For instance:

git push origin foo:foo_test

As you are doing the push, you can tell your git push to set your branch's upstream name at the same time, by adding -u to the git push options. Setting the upstream name makes your git save the foo_test (or whatever) name, so that a future git push with no arguments, while you're on the foo branch, can try to push to foo_test on the remote (git also saves the remote, origin in this case, so that you don't have to enter that either).

You need only pass -u once: it basically just runs git branch --set-upstream-to for you. (If you pass -u again later, it re-runs the upstream-setting, changing it as directed; or you can run git branch --set-upstream-to yourself.)

However, if your git is 2.0 or newer, and you have not set any special configuration, you will run into the same kind of thing that had me enter footnote 1 above: push.default will be set to simple, which will refuse to push because the upstream's name differs from your own local name. If you set push.default to upstream, git will stop complaining—but the simplest solution is just to rename your local branch first, so that the local and remote names match. (What settings to set, and/or whether to rename your branch, are up to you.)


1More precisely, git consults your remote.remote.push setting to derive the upstream half of the refspec. If you haven't set anything here, the default is to use the same name.

2This doesn't have to be a branch name. For instance, you can supply HEAD, or a commit hash, here. If you use something other than a branch name, you may have to spell out the full refs/heads/branch on the right, though (it depends on what names are already on the remote).

What is the difference between Class.getResource() and ClassLoader.getResource()?

Class.getResources would retrieve the resource by the classloader which load the object. While ClassLoader.getResource would retrieve the resource using the classloader specified.

SQL ROWNUM how to return rows between a specific range

SELECT * FROM
(SELECT ROW_NUMBER() OVER(ORDER BY Id) AS RowNum, * FROM maps006) AS DerivedTable
WHERE RowNum BETWEEN 49 AND 101

Detect Scroll Up & Scroll down in ListView

Store the firstVisibleItem and on the next onScroll check if the new firstVisibleItem is smaller or greater than the previous one.

Example pseudocode (not tested):

int lastVisibleItem = 0;
boolean isScrollingDown = false;

void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
    if (firstVisibleItem > lastVisibleItem) {
        isScrollingDown = true;
    }
    else {
        isScrollingDown = false;
    }
    lastVisibleItem = firstVisibleItem;
}

Html.Textbox VS Html.TextboxFor

Html.TextBox amd Html.DropDownList are not strongly typed and hence they doesn't require a strongly typed view. This means that we can hardcode whatever name we want. On the other hand, Html.TextBoxFor and Html.DropDownListFor are strongly typed and requires a strongly typed view, and the name is inferred from the lambda expression.

Strongly typed HTML helpers also provide compile time checking.

Since, in real time, we mostly use strongly typed views, prefer to use Html.TextBoxFor and Html.DropDownListFor over their counterparts.

Whether, we use Html.TextBox & Html.DropDownList OR Html.TextBoxFor & Html.DropDownListFor, the end result is the same, that is they produce the same HTML.

Strongly typed HTML helpers are added in MVC2.

onclick="javascript:history.go(-1)" not working in Chrome

Use the below one, it's way better than the history.go(-1).

<a href="#" onclick="location.href = document.referrer; return false;"> Go TO Previous Page</a>

Determining 32 vs 64 bit in C++

template<int> void DoMyOperationHelper();

template<> void DoMyOperationHelper<4>() 
{
  // do 32-bits operations
}

template<> void DoMyOperationHelper<8>() 
{
  // do 64-bits operations
}

// helper function just to hide clumsy syntax
inline void DoMyOperation() { DoMyOperationHelper<sizeof(size_t)>(); }

int main()
{
  // appropriate function will be selected at compile time 
  DoMyOperation(); 

  return 0;
}

Java AES encryption and decryption

Complete example of encrypting/Decrypting a huge video without throwing Java OutOfMemoryException and using Java SecureRandom for Initialization Vector generation. Also depicted storing key bytes to database and then reconstructing same key from those bytes.

https://stackoverflow.com/a/18892960/185022

Git: How to pull a single file from a server repository in Git?

Try using:

git checkout branchName -- fileName

Ex:

git checkout master -- index.php

Windows equivalent of linux cksum command

In Windows (command prompt) you can use CertUtil, here is the syntax:

CertUtil [Options] -hashfile InFile [HashAlgorithm]

for syntax explanation type in cmd:

CertUtil -hashfile -?

example:

CertUtil -hashfile C:\myFile.txt MD5

default is SHA1 it supports: MD2, MD4, MD5, SHA1, SHA256, SHA384, SHA512. Unfortunately no CRC32 as Unix shell does.

Here is a link if you want to find out more https://technet.microsoft.com/en-us/library/cc732443.aspx#BKMK_menu

How to use jQuery Plugin with Angular 4?

You should not use jQuery in Angular. While it is possible (see other answers for this question), it is discouraged. Why?

Angular holds an own representation of the DOM in its memory and doesn't use query-selectors (functions like document.getElementById(id)) like jQuery. Instead all the DOM-manipulation is done by Renderer2 (and Angular-directives like *ngFor and *ngIf accessing that Renderer2 in the background/framework-code). If you manipulate DOM with jQuery yourself you will sooner or later...

  1. Run into synchronization problems and have things wrongly appearing or not disappearing at the right time from your screen
  2. Have performance issues in more complex components, as Angular's internal DOM-representation is bound to zone.js and its change detection-mechanism - so updating the DOM manually will always block the thread your app is running on.
  3. Have other confusing errors you don't know the origin of.
  4. Not being able to test the application correctly (Jasmine requires you to know when elements have been rendered)
  5. Not being able to use Angular Universal or WebWorkers

If you really want to include jQuery (for duck-taping some prototype that you will 100% definitively throw away), I recommend to at least include it in your package.json with npm install --save jquery instead of getting it from google's CDN.

TLDR: For learning how to manipulate the DOM in the Angular way please go through the official tour-of heroes tutorial first: https://angular.io/tutorial/toh-pt2 If you need to access elements higher up in the DOM hierarchy (parent or document body) or for some other reason directives like *ngIf, *ngFor, custom directives, pipes and other angular utilities like [style.background], [class.myOwnCustomClass] don't satisfy your needs, use Renderer2: https://www.concretepage.com/angular-2/angular-4-renderer2-example

Calling a PHP function from an HTML form in the same file

You can submit the form without refreshing the page, but to my knowledge it is impossible without using a JavaScript/Ajax call to a PHP script on your server. The following example uses the jQuery JavaScript library.

HTML

<form method = 'post' action = '' id = 'theForm'>
...
</form>

JavaScript

$(function() {
    $("#theForm").submit(function() {
        var data = "a=5&b=6&c=7";
        $.ajax({
            url: "path/to/php/file.php",
            data: data,
            success: function(html) {
                .. anything you want to do upon success here ..
                alert(html); // alert the output from the PHP Script
            }
        });
        return false;
    });
});

Upon submission, the anonymous Javascript function will be called, which simply sends a request to your PHP file (which will need to be in a separate file, btw). The data above needs to be a URL-encoded query string that you want to send to the PHP file (basically all of the current values of the form fields). These will appear to your server-side PHP script in the $_GET super global. An example is below.

var data = "a=5&b=6&c=7";

If that is your data string, then the PHP script will see this as:

echo($_GET['a']); // 5
echo($_GET['b']); // 6
echo($_GET['c']); // 7

You, however, will need to construct the data from the form fields as they exist for your form, such as:

var data = "user=" + $("#user").val();

(You will need to tag each form field with an 'id', the above id is 'user'.)

After the PHP script runs, the success function is called, and any and all output produced by the PHP script will be stored in the variable html.

...
success: function(html) {
    alert(html);
}
...

Delete all documents from index/type without deleting type

Note for ES2+

Starting with ES 1.5.3 the delete-by-query API is deprecated, and is completely removed since ES 2.0

Instead of the API, the Delete By Query is now a plugin.

In order to use the Delete By Query plugin you must install the plugin on all nodes of the cluster:

sudo bin/plugin install delete-by-query

All of the nodes must be restarted after the installation.


The usage of the plugin is the same as the old API. You don't need to change anything in your queries - this plugin will just make them work.


*For complete information regarding WHY the API was removed you can read more here.