Programs & Examples On #Google voice

Google Voice is a telecommunications service offering enhanced: voicemail, forwarding, conferencing, etc. -- coordinated across all of your voice devices and managed on the web.

Remove quotes from String in Python

You can replace "quote" characters with an empty string, like this:

>>> a = '"sajdkasjdsak" "asdasdasds"' 
>>> a
'"sajdkasjdsak" "asdasdasds"'
>>> a = a.replace('"', '')
>>> a
'sajdkasjdsak asdasdasds'

In your case, you can do the same for out variable.

Is there a Google Voice API?

I looked for a C/C++ API for Google Voice for quite a while and never found anything close (the closest was a C# API). Since I really needed it, I decided to just write one myself:

I hope others find it useful. Feedback and suggestions welcome.

General error: 1364 Field 'user_id' doesn't have a default value

In my case, the error was because I had not declared the field in my $fillable array in the model. Well, it seems to be something basic, but for us who started with laravel it could work.

How do I get the HTML code of a web page in PHP?

You may want to check out the YQL libraries from Yahoo:

The task at hand is as simple as

select * from html where url = ''

You can try this out in the console at: (requires login)

Also see Chris Heilmanns screencast for some nice ideas what more you can do:

pros and cons between os.path.exists vs os.path.isdir

os.path.isdir() checks if the path exists and is a directory and returns TRUE for the case.

Similarly, os.path.isfile() checks if the path exists and is a file and returns TRUE for the case.

And, os.path.exists() checks if the path exists and doesn’t care if the path points to a file or a directory and returns TRUE in either of the cases.

@AspectJ pointcut for all methods of a class with specific annotation

Something like that:

@Before("execution(* com.yourpackage..*.*(..))")
public void monitor(JoinPoint jp) {
    if (jp.getTarget().getClass().isAnnotationPresent(Monitor.class)) {
       // perform the monitoring actions

Note that you must not have any other advice on the same class before this one, because the annotations will be lost after proxying.

Instagram how to get my user id from username?

Working Solution December 14, 2020

For simple usage like 3rd party tools that require an Instagram user ID (like embedding an image feed) I tend to use:

because it makes it really easy to copy and paste the Instagram user ID that I am looking for. Unlike most tools I get the results fast, it's free and there are no ads. I recommend you watch the youtube video before using it so you can see how simple it is and get an idea of how it's used:

For more advanced usage I recommend:{username}/?__a=1

(replace username with the requested username)

For example to find the user ID of the username "instagram" you would use:

This is the most advanced way which returns a JSON response and it's great if you are building an app that requires the raw data. You can save it in a database or build some type of front end UI to display it. Example: for a dashboard or on a website. Also, using the url is great because you can get additional attributes about users such as their total follower count and profile bio.

R for loop skip to next iteration ifelse

for(n in 1:5) {
  if(n==3) next # skip 3rd iteration and go to next iteration

"unable to locate adb" using Android Studio

I fixed this issue by deleting and inserting new platform-tools folder inside android sdk folder. But it is caused by my Avast anti virus software. Where I can found my adb.exe in Avast chest. You can also solve by restoring it from Avast chest.

How to make an ng-click event conditional?

It is not good to manipulate with DOM (including checking of attributes) in any place except directives. You can add into scope some value indicating if link should be disabled.

But other problem is that ngDisabled does not work on anything except form controls, so you can't use it with <a>, but you can use it with <button> and style it as link.

Another way is to use lazy evaluation of expressions like isDisabled || action() so action wouold not be called if isDisabled is true.

Here goes both solutions:

Execution Failed for task :app:compileDebugJavaWithJavac in Android Studio

I got this issue solved.

I was trying to compile this project "Waveform Android" -

and got I this error.

I am using Android studio on Ubuntu 14.04LTS.

I have JAVA 8 Installed.

in my gradle build script file there was some statements as below.

retrolambda {
    jdk System.getenv("JAVA8_HOME")
    oldJdk System.getenv("JAVA7_HOME")
    javaVersion JavaVersion.VERSION_1_7

I changed the "JAVA8_HOME" to "JAVA_HOME" because in my environment variables the java home directory is set as JAVA_HOME not as JAVA8_HOME and then It built succesfully.

after changing the build script.

retrolambda {
    jdk System.getenv("JAVA_HOME")
    oldJdk System.getenv("JAVA7_HOME")
    javaVersion JavaVersion.VERSION_1_7

Or the other way you can create a new environment variable named JAVA8_HOME pointing to the right JDK location, but I have not tried that though because I dont want environment variables for each JDK version.

What is the best comment in source code you have ever encountered?

Something I saw in a .h file years ago.

// It may be a hack, but it works.

$.browser is undefined error

The .browser call has been removed in jquery 1.9 have a look at for more details.

How to get rid of "Unnamed: 0" column in a pandas DataFrame?

It's the index column, pass pd.to_csv(..., index=False) to not write out an unnamed index column in the first place, see the to_csv() docs.


In [37]:
df = pd.DataFrame(np.random.randn(5,3), columns=list('abc'))

   Unnamed: 0         a         b         c
0           0  0.109066 -1.112704 -0.545209
1           1  0.447114  1.525341  0.317252
2           2  0.507495  0.137863  0.886283
3           3  1.452867  1.888363  1.168101
4           4  0.901371 -0.704805  0.088335

compare with:

In [38]:

          a         b         c
0  0.109066 -1.112704 -0.545209
1  0.447114  1.525341  0.317252
2  0.507495  0.137863  0.886283
3  1.452867  1.888363  1.168101
4  0.901371 -0.704805  0.088335

You could also optionally tell read_csv that the first column is the index column by passing index_col=0:

In [40]:
pd.read_csv(io.StringIO(df.to_csv()), index_col=0)

          a         b         c
0  0.109066 -1.112704 -0.545209
1  0.447114  1.525341  0.317252
2  0.507495  0.137863  0.886283
3  1.452867  1.888363  1.168101
4  0.901371 -0.704805  0.088335

Bash scripting, multiple conditions in while loop

The extra [ ] on the outside of your second syntax are unnecessary, and possibly confusing. You may use them, but if you must you need to have whitespace between them.


while [ $stats -gt 300 ] || [ $stats -eq 0 ]

How to install easy_install in Python 2.7.1 on Windows 7

Look for the official 2.7 setuptools installer (which contains easy_install). You only need to install from sources for windows 64 bits.

Using Default Arguments in a Function

In PHP 8 we can use named arguments for this problem.

So we could solve the problem described by the original poster of this question:

What if I want to use the default argument for $x and set a different argument for $y?


foo(blah: "blah", y: "test");

Reference: (in particular the "Skipping defaults" section)

Get the current URL with JavaScript?

var currentPageUrlIs = "";
if (typeof this.href != "undefined") {
       currentPageUrlIs = this.href.toString().toLowerCase(); 
       currentPageUrlIs = document.location.toString().toLowerCase();

The above code can also help someone

Maven: Failed to retrieve plugin descriptor error

Mac OSX 10.7.5: I tried setting my proxy in the settings.xml file (as mentioned by posters above) in the /conf directory and also in the ~/.m2 directory, but still I got this error. I downloaded the latest version of Maven (3.1.1), and set my PATH variable to reflect the latest install, and it worked for me right off the shelf without any error.

Convert string to title case with JavaScript

This is one line solution, if you want convert every work in the string, Split the string by " ", iterate over the parts and apply this solution to each part, add every converted part to a array and join it with " ".

var stringToConvert = 'john';_x000D_
stringToConvert = stringToConvert.charAt(0).toUpperCase() +, 1).join('');_x000D_

How to change the Content of a <textarea> with JavaScript

Like this:

document.getElementById('myTextarea').value = '';

or like this in jQuery:


Where you have

<textarea id="myTextarea" name="something">This text gets removed</textarea>

For all the downvoters and non-believers:

What exactly is LLVM?

LLVM (used to mean "Low Level Virtual Machine" but not anymore) is a compiler infrastructure, written in C++, which is designed for compile-time, link-time, run-time, and "idle-time" optimization of programs written in arbitrary programming languages. Originally implemented for C/C++, the language-independent design (and the success) of LLVM has since spawned a wide variety of front-ends, including Objective C, Fortran, Ada, Haskell, Java bytecode, Python, Ruby, ActionScript, GLSL, and others.

Read this for more explanation
Also check out Unladen Swallow

Warning: Attempt to present * on * whose view is not in the window hierarchy - swift

I have tried so many approches! the only useful thing is:

if var topController = UIApplication.shared.keyWindow?.rootViewController
  while (topController.presentedViewController != nil)
    topController = topController.presentedViewController!

Form onSubmit determine which submit button was pressed

Not in the submit event handler itself, no.

But what you can do is add click handlers to each submit which will inform the submit handler as to which was clicked.

Here's a full example (using jQuery for brevity)

  <title>Test Page</title>
  <script src=""></script>
  <script type="text/javascript">

  jQuery(function($) {
      var submitActor = null;
      var $form = $('#test');
      var $submitActors = $form.find('input[type=submit]');

      $form.submit(function(event) {
          if (null === submitActor) {
              // If no actor is explicitly clicked, the browser will
              // automatically choose the first in source-order
              // so we do the same here
              submitActor = $submitActors[0];

          // alert(;

          return false;

      $ {
          submitActor = this;



  <form id="test">

    <input type="text" />

    <input type="submit" name="save" value="Save" />
    <input type="submit" name="saveAndAdd" value="Save and add another" />



insert password into database in md5 format?

if you want to use md5 encryptioon you can do it in your php script

$pass = $_GET['pass'];

$newPass = md5($pass)

and then insert it into the database that way, however MD5 is a one way encryption method and is near on impossible to decrypt without difficulty

'Property does not exist on type 'never'

Because you are assigning instance to null. The compiler infers that it can never be anything other than null. So it assumes that the else block should never be executed so instance is typed as never in the else block.

Now if you don't declare it as the literal value null, and get it by any other means (ex: let instance: Foo | null = getFoo();), you will see that instance will be null inside the if block and Foo inside the else block.

Never type documentation:


The issue in the updated example is actually an open issue with the compiler. See:

How to detect orientation change in layout in Android?

Create an instance of OrientationEventListener class and enable it.

OrientationEventListener mOrientationEventListener = new OrientationEventListener(YourActivity.this) {
    public void onOrientationChanged(int orientation) {
        Log.d(TAG,"orientation = " + orientation);

if (mOrientationEventListener.canDetectOrientation())

Getting return value from stored procedure in C#

I was having tons of trouble with the return value, so I ended up just selecting stuff at the end.

The solution was just to select the result at the end and return the query result in your functinon.

In my case I was doing an exists check:

IF (EXISTS (SELECT RoleName FROM dbo.Roles WHERE @RoleName = RoleName)) 
    SELECT 1
    SELECT 0


using (SqlConnection cnn = new SqlConnection(ConnectionString))
    SqlCommand cmd = cnn.CreateCommand();
    cmd.CommandType = CommandType.StoredProcedure;
    cmd.CommandText = "RoleExists";
    return (int) cmd.ExecuteScalar()

You should be able to do the same thing with a string value instead of an int.

How to display my application's errors in JSF?

JSF is a beast. I may be missing something, but I used to solve similar problems by saving the desired message to a property of the bean, and then displaying the property via an outputText:

    render="#{CreateNewPasswordBean.errorMessage != null}" />

Open link in new tab or window

It shouldn't be your call to decide whether the link should open in a new tab or a new window, since ultimately this choice should be done by the settings of the user's browser. Some people like tabs; some like new windows.

Using _blank will tell the browser to use a new tab/window, depending on the user's browser configuration and how they click on the link (e.g. middle click, Ctrl+click, or normal click).

Difference between jar and war in Java

JAR files allow to package multiple files in order to use it as a library, plugin, or any kind of application. On the other hand, WAR files are used only for web applications.

JAR can be created with any desired structure. In contrast, WAR has a predefined structure with WEB-INF and META-INF directories.

A JAR file allows Java Runtime Environment (JRE) to deploy an entire application including the classes and the associated resources in a single request. On the other hand, a WAR file allows testing and deploying a web application easily.

Sending a JSON to server and retrieving a JSON in return, without JQuery

Sending and receiving data in JSON format using POST method

// Sending and receiving data in JSON format using POST method
var xhr = new XMLHttpRequest();
var url = "url";"POST", url, true);
xhr.setRequestHeader("Content-Type", "application/json");
xhr.onreadystatechange = function () {
    if (xhr.readyState === 4 && xhr.status === 200) {
        var json = JSON.parse(xhr.responseText);
        console.log( + ", " + json.password);
var data = JSON.stringify({"email": "[email protected]", "password": "101010"});

Sending and receiving data in JSON format using GET method

// Sending a receiving data in JSON format using GET method
var xhr = new XMLHttpRequest();
var url = "url?data=" + encodeURIComponent(JSON.stringify({"email": "[email protected]", "password": "101010"}));"GET", url, true);
xhr.setRequestHeader("Content-Type", "application/json");
xhr.onreadystatechange = function () {
    if (xhr.readyState === 4 && xhr.status === 200) {
        var json = JSON.parse(xhr.responseText);
        console.log( + ", " + json.password);

Handling data in JSON format on the server-side using PHP

// Handling data in JSON format on the server-side using PHP
header("Content-Type: application/json");
// build a PHP variable from JSON sent using POST method
$v = json_decode(stripslashes(file_get_contents("php://input")));
// build a PHP variable from JSON sent using GET method
$v = json_decode(stripslashes($_GET["data"]));
// encode the PHP variable to JSON and send it back on client-side
echo json_encode($v);

The limit of the length of an HTTP Get request is dependent on both the server and the client (browser) used, from 2kB - 8kB. The server should return 414 (Request-URI Too Long) status if an URI is longer than the server can handle.

Note Someone said that I could use state names instead of state values; in other words I could use xhr.readyState === xhr.DONE instead of xhr.readyState === 4 The problem is that Internet Explorer uses different state names so it's better to use state values.

What is a "bundle" in an Android application

Bundle:- A mapping from String values to various Parcelable types.

Bundle is generally used for passing data between various activities of android.

when we call onPause() then onStop() and then in reverse order onStop() to onPause().

The saved data that the system uses to restore the previous state is called the "instance state" and is a collection of key-value pairs stored in a Bundle object.

Escaping Double Quotes in Batch Script

Google eventually came up with the answer. The syntax for string replacement in batch is this:

set v_myvar=replace me
set v_myvar=%v_myvar:ace=icate%

Which produces "replicate me". My script now looks like this:

@echo off
set v_params=%*
set v_params=%v_params:"=\"%
call bash -c "g++-linux-4.1 %v_params%"

Which replaces all instances of " with \", properly escaped for bash.

How to create Drawable from resource

This code is deprecated:

Drawable drawable = getResources().getDrawable( R.drawable.icon );

Use this instead:

Drawable drawable = ContextCompat.getDrawable(getApplicationContext(),R.drawable.icon);

How do I get Flask to run on port 80?

Easiest and Best Solution

Save your .py file in a folder. This case my folder name is test. In the command prompt run the following

c:\test> set
c:\test> set FLASK_RUN_PORT=8000
c:\test> flask run

----------------- Following will be returned ----------------

 * Serving Flask app ""
 * Environment: production
   WARNING: Do not use the development server in a production environment.
   Use a production WSGI server instead.
 * Debug mode: off
 * Running on (Press CTRL+C to quit) - - [23/Aug/2019 09:40:04] "[37mGET / HTTP/1.1[0m" 200 - - - [23/Aug/2019 09:40:04] "[33mGET /favicon.ico HTTP/1.1[0m" 404 -

Now on your browser type: Thanks

The shortest possible output from git log containing author and date

git log --pretty=format:"%H %an %ad"

use --date= to set a date format

git log --pretty=format:"%H %an %ad" --date=short

JQuery: detect change in input field

Use $.on() to bind your chosen event to the input, don't use the shortcuts like $.keydown() etc because as of jQuery 1.7 $.on() is the preferred method to attach event handlers (see here: and

$.keydown() is just a shortcut to $.bind('keydown'), and $.bind() is what $.on() replaces (among others).

To answer your question, as far as I'm aware, unless you need to fire an event on keydown specifically, the change event should do the trick for you.

$('element').on('change', function(){

To respond to the below comment, the javascript change event is documented here:

And here is a working example of the change event working on an input element, using jQuery:

Labeling file upload button

To make a custom "browse button" solution simply try making a hidden browse button, a custom button or element and some Jquery. This way I'm not modifying the actual "browse button" which is dependent on each browser/version. Here's an example.


<div id="import" type="file">My Custom Button</div>
<input id="browser" class="hideMe" type="file"></input>


#import {
  margin: 0em 0em 0em .2em;
  content: 'Import Settings';
  display: inline-block;
  border: 1px solid;
  border-color: #ddd #bbb #999;
  border-radius: 3px;
  padding: 5px 8px;
  outline: none;
  white-space: nowrap;
  -webkit-user-select: none;
  cursor: pointer;
  font-weight: 700;
  font: bold 12px/1.2 Arial,sans-serif !important;
  /* fallback */
  background-color: #f9f9f9;
  /* Safari 4-5, Chrome 1-9 */
  background: -webkit-gradient(linear, 0% 0%, 0% 100%, from(#C2C1C1), to(#2F2727));

    display: none;


$("#import").click(function() {
    $('#browser').change(function() {

Solving "The ObjectContext instance has been disposed and can no longer be used for operations that require a connection" InvalidOperationException

If you're using ASP.NET Core and wonder why you get this message in one of your async controller methods, make sure you return a Task rather than void - ASP.NET Core disposes injected contexts.

(I'm posting this answer as this question is high in the search results to that exception message and it's a subtle issue - maybe it's useful to people who Google for it.)

Using std::max_element on a vector<double>

min/max_element return the iterator to the min/max element, not the value of the min/max element. You have to dereference the iterator in order to get the value out and assign it to a double. That is:

cLower = *min_element(C.begin(), C.end());

Error in Chrome only: XMLHttpRequest cannot load file URL No 'Access-Control-Allow-Origin' header is present on the requested resource

This is supposedly because you trying to make cross-domain request, or something that is clarified as it. You could try adding header('Access-Control-Allow-Origin: *'); to the requested file.

Also, such problem is sometimes occurs on server-sent events implementation in case of using event-source or XHR polling in IE 8-10 (which confused me first time).

Creating an Array from a Range in VBA

Using Value2 gives a performance benefit. As per Charles Williams blog

Range.Value2 works the same way as Range.Value, except that it does not check the cell format and convert to Date or Currency. And thats probably why its faster than .Value when retrieving numbers.


DirArray = [a1:a5].Value2

Bonus Reading

  • Range.Value: Returns or sets a Variant value that represents the value of the specified range.
  • Range.Value2: The only difference between this property and the Value property is that the Value2 property doesn't use the Currency and Date data types.

Comparing user-inputted characters in C

answer shouldn't be a pointer, the intent is obviously to hold a character. scanf takes the address of this character, so it should be called as

char answer;
scanf(" %c", &answer);

Next, your "or" statement is formed incorrectly.

if (answer == 'Y' || answer == 'y')

What you wrote originally asks to compare answer with the result of 'Y' || 'y', which I'm guessing isn't quite what you wanted to do.

Protractor : How to wait for page complete after click a button?

With Protractor, you can use the following approach

var EC = protractor.ExpectedConditions;
// Wait for new page url to contain newPageName
browser.wait(EC.urlContains('newPageName'), 10000);

So your code will look something like,


var EC = protractor.ExpectedConditions;
// Wait for new page url to contain efg
ptor.wait(EC.urlContains('efg'), 10000);

expect(ptor.getCurrentUrl()).toEqual(url + 'abc#/efg');

Note: This may not mean that new page has finished loading and DOM is ready. The subsequent 'expect()' statement will ensure Protractor waits for DOM to be available for test.

Reference: Protractor ExpectedConditions

SMTP connect() failed PHPmailer - PHP

 $mail->SMTPOptions = array(
        'ssl' => array(
            'verify_peer' => false,
            'verify_peer_name' => false,
            'allow_self_signed' => true

How to sort a HashSet?

you can do this in the following ways:

Method 1:

  1. Create a list and store all the hashset values into it
  2. sort the list using Collections.sort()
  3. Store the list back into LinkedHashSet as it preserves the insertion order

Method 2:

  • Create a treeSet and store all the values into it.

Method 2 is more preferable because the other method consumes lot of time to transfer data back and forth between hashset and list.

apache server reached MaxClients setting, consider raising the MaxClients setting

I recommend to use bellow formula suggested on Apache:

MaxClients = (total RAM - RAM for OS - RAM for external programs) / (RAM per httpd process)

Find my script here which is running on Rhel 6.7. you can made change according to your OS.


echo "HostName=`hostname`"

#MaxClients . (RAM - size_all_other_processes)/(size_apache_process)
total_httpd_processes_size=`ps -ylC httpd --sort:rss | awk '{ sum += $9 } END { print sum }'`
#echo "total_httpd_processes_size=$total_httpd_processes_size"
total_http_processes_count=`ps -ylC httpd --sort:rss | wc -l`
echo "total_http_processes_count=$total_http_processes_count"
AVG_httpd_process_size=$(expr $total_httpd_processes_size / $total_http_processes_count)
echo "AVG_httpd_process_size=$AVG_httpd_process_size"
total_httpd_process_size_MB=$(expr $AVG_httpd_process_size / 1024)
echo "total_httpd_process_size_MB=$total_httpd_process_size_MB"
total_pttpd_used_size=$(expr $total_httpd_processes_size / 1024)
echo "total_pttpd_used_size=$total_pttpd_used_size"
total_RAM_size=`free -m |grep Mem |awk '{print $2}'`
echo "total_RAM_size=$total_RAM_size"
total_used_size=`free -m |grep Mem |awk '{print $3}'`
echo "total_used_size=$total_used_size"
size_all_other_processes=$(expr $total_used_size - $total_pttpd_used_size)
echo "size_all_other_processes=$size_all_other_processes"
remaining_memory=$(($total_RAM_size - $size_all_other_processes))
echo "remaining_memory=$remaining_memory"
MaxClients=$((($total_RAM_size - $size_all_other_processes) / $total_httpd_process_size_MB))
echo "MaxClients=$MaxClients"

Creating an empty list in Python

Just to highlight @Darkonaut answer because I think it should be more visible.

new_list = [] or new_list = list() are both fine (ignoring performance), but append() returns None, as result you can't do new_list = new_list.append(something).

sudo: docker-compose: command not found

I will leave this here as a possible fix, worked for me at least and might help others. Pretty sure this would be a linux only fix.

I decided to not go with the pip install and go with the github version (option one on the installation guide).

Instead of placing the copied docker-compose directory into /usr/local/bin/docker-compose from the curl/github command, I went with /usr/bin/docker-compose which is the location of Docker itself and will force the program to run in root. So it works in root and sudo but now won't work without sudo so the opposite effect which is what you want to run it as a user anyways.

Rails: How can I set default values in ActiveRecord?

This is what constructors are for! Override the model's initialize method.

Use the after_initialize method.

How do I parse JSON from a Java HTTPResponse?

Use JSON Simple,

Which has a small foot-print, no dependencies so it's perfect for Android.

You can do something like this,

Object obj=JSONValue.parse(buffer.tString());
JSONArray finalResult=(JSONArray)obj;

PuTTY scripting to log onto host

When you use the -m option putty does not allocate a tty, it runs the command and quits. If you want to run an interactive script (such as a sql client), you need to tell it to allocate a tty with -t, see -t and -T: control pseudo-terminal allocation. You'll avoid keeping a script on the server, as well as having to invoke it once you're connected.

Here's what I'm using to connect to mysql from a batch file:

#mysql.bat start putty -t -load "sessionname" -l username -pw password -m c:\ mysql -h localhost -u username --password="foo" mydb

Displaying a vector of strings in C++

You ask two questions; your title says "Displaying a vector of strings", but you're not actually doing that, you actually build a single string composed of all the strings and output that.

Your question body asks "Why doesn't this work".

It doesn't work because your for loop is constrained by "userString.size()" which is 0, and you test your loop variable for being "userString.size() - 1". The condition of a for() loop is tested before permitting execution of the first iteration.

int n = 1;
for (int i = 1; i < n; ++i) {
    std::cout << i << endl;

will print exactly nothing.

So your loop executes exactly no iterations, leaving userString and sentence empty.

Lastly, your code has absolutely zero reason to use a vector. The fact that you used "decltype(userString.size())" instead of "size_t" or "auto", while claiming to be a rookie, suggests you're either reading a book from back to front or you are setting yourself up to fail a class.

So to answer your question at the end of your post: It doesn't work because you didn't step through it with a debugger and inspect the values as it went. While I say it tongue-in-cheek, I'm going to leave it out there.

C++ code file extension? .cc vs .cpp

At the end of the day it doesn't matter because C++ compilers can deal with the files in either format. If it's a real issue within your team, flip a coin and move on to the actual work.

How to replace multiple substrings of a string?

This is just a more concise recap of F.J and MiniQuark great answers. All you need to achieve multiple simultaneous string replacements is the following function:

def multiple_replace(string, rep_dict):
    pattern = re.compile("|".join([re.escape(k) for k in sorted(rep_dict,key=len,reverse=True)]), flags=re.DOTALL)
    return pattern.sub(lambda x: rep_dict[], string)


>>>multiple_replace("Do you like cafe? No, I prefer tea.", {'cafe':'tea', 'tea':'cafe', 'like':'prefer'})
'Do you prefer tea? No, I prefer cafe.'

If you wish, you can make your own dedicated replacement functions starting from this simpler one.

fatal error LNK1104: cannot open file 'libboost_system-vc110-mt-gd-1_51.lib'

Yet another solution:

I was stumped because I was including boost_regex-vc120-mt-gd-1_58.lib in my Link->Additional Dependencies property, but the link kept telling me it couldn't open libboost_regex-vc120-mt-gd-1_58.lib (note the lib prefix). I didn't specify libboost_regex-vc120-mt-gd-1_58.lib.

I was trying to use (and had built) the boost dynamic libraries (.dlls) but did not have the BOOST_ALL_DYN_LINK macro defined. Apparently there are hints in the compile to include a library, and without BOOST_ALL_DYN_LINK it looks for the static library (with the lib prefix), not the dynamic library (without a lib prefix).

Negate if condition in bash script


if ! wget -q --spider --tries=10 --timeout=20
  echo 'Sorry you are Offline'
  exit 1

How to get highcharts dates in the x axis?

You write like this-:

xAxis: {
        type: 'datetime',
        dateTimeLabelFormats: {
           day: '%d %b %Y'    //ex- 01 Jan 2016

also check for other datetime format

How can I include null values in a MIN or MAX?

Use the analytic function :

select case when 
    max(field) keep (dense_rank first order by datfin desc nulls first) is null then 1 
    else 0 end as flag 

How to do a FULL OUTER JOIN in MySQL?

what'd you say about Cross join solution?

SELECT t1.*, t2.*
FROM table1 t1
INNER JOIN table2 t2 
ON 1=1;

Display JSON Data in HTML Table

 <div id="container"></div>   

$('#search').click(function() {
        type: 'POST',
        url: 'cityResults.htm',
        data: $('#cityDetails').serialize(),
        dataType:"json", //to parse string into JSON object,
        success: function(data){ 

                var len = data.length;
                var txt = "";
                if(len > 0){
                    for(var i=0;i<len;i++){

                            txt = "<tr><td>"+data[i].city+"</td><td>"+data[i].cStatus+"</td></tr>";

        error: function(jqXHR, textStatus, errorThrown){
            alert('error: ' + textStatus + ': ' + errorThrown);
    return false;

How to send data with angularjs $http.delete() request?

I would suggest reading this url$resource

and revaluate how you are calling your delete method of your resources.

ideally you would want to be calling the delete of the resource item itself and by not passing the id of the resource into a catch all delete method

however $http.delete accepts a config object that contains both url and data properties you could either craft the query string there or pass an object/string into the data

maybe something along these lines

$http.delete('/roles/'+roleid, {data: input});

How to get a function name as a string?

If you're interested in class methods too, Python 3.3+ has __qualname__ in addition to __name__.

def my_function():

class MyClass(object):
    def method(self):

print(my_function.__name__)         # gives "my_function"
print(MyClass.method.__name__)      # gives "method"

print(my_function.__qualname__)     # gives "my_function"
print(MyClass.method.__qualname__)  # gives "MyClass.method"

Android Eclipse - Could not find *.apk

Please follow these steps; this might help you out:

  1. Right-click your app project and go to Properties

  2. Select Android from left-hand side list

  3. Uncheck the "Is Library" checkbox

If your app project relies on library projects which are in your workspace, those of course need to have the "Is Library" box checked.

What linux shell command returns a part of a string?

From the bash manpage:

        Substring  Expansion.   Expands  to  up  to length characters of
        parameter starting at the character  specified  by  offset.

Or, if you are not sure of having bash, consider using cut.

in a "using" block is a SqlConnection closed on return or exception?

  1. Yes
  2. Yes.

Either way, when the using block is exited (either by successful completion or by error) it is closed.

Although I think it would be better to organize like this because it's a lot easier to see what is going to happen, even for the new maintenance programmer who will support it later:

using (SqlConnection connection = new SqlConnection(connectionString)) 
    int employeeID = findEmployeeID();    
        SqlCommand command = new SqlCommand("UpdateEmployeeTable", connection);
        command.CommandType = CommandType.StoredProcedure;
        command.Parameters.Add(new SqlParameter("@EmployeeID", employeeID));
        command.CommandTimeout = 5;

    catch (Exception) 
        /*Handle error*/ 

How to get rid of punctuation using NLTK tokenizer?

I just used the following code, which removed all the punctuation:

tokens = nltk.wordpunct_tokenize(raw)


text = nltk.Text(tokens)


words = [w.lower() for w in text if w.isalpha()]

How to create a session using JavaScript?

You can use Local storage.

local storage is same as session. the data will be removed when you close the browser.



Edit: @Naveen comment below is correct. You can use session storage instead. ( Thanks.



How do I add an active class to a Link from React Router?

This is my way, using location from props. I don't know but history.isActive got undefined for me

export default class Navbar extends React.Component {
const { location } = this.props;

const homeClass = location.pathname === "/" ? "active" : "";
const aboutClass = location.pathname.match(/^\/about/) ? "active" : "";
const contactClass = location.pathname.match(/^\/contact/) ? "active" : "";

return (
      <ul className="nav navbar-nav navbar-right">
        <li className={homeClass}><Link to="/">Home</Link></li>
        <li className={aboutClass}><Link to="about" activeClassName="active">About</Link></li>
        <li className={contactClass}><Link to="contact" activeClassName="active">Contact</Link></li>


What is causing ImportError: No module named pkg_resources after upgrade of Python on os X?

I realize this is not related to OSX, but on an embedded system (Beagle Bone Angstrom) I had the exact same error message. Installing the following ipk packages solved it.

opkg install python-setuptools
opkg install python-pip

SQL - How to find the highest number in a column?

Here's how I would make the next ID:

INSERT INTO table_name (
            VALUES ((( 
                    SELECT COALESCE(MAX(B.ID)+1,1) AS NEXTID 
                        FROM table_name B
                        )), John2, Smith2);

With this you can make sure that even if the table ID is NULL, it will still work perfectly.

How to read a single character from the user?

The curses package in python can be used to enter "raw" mode for character input from the terminal with just a few statements. Curses' main use is to take over the screen for output, which may not be what you want. This code snippet uses print() statements instead, which are usable, but you must be aware of how curses changes line endings attached to output.

# Demo of single char terminal input in raw mode with the curses package.
import sys, curses

def run_one_char(dummy):
    'Run until a carriage return is entered'
    char = ' '
    print('Welcome to curses', flush=True)
    while ord(char) != 13:
        char = one_char()

def one_char():
    'Read one character from the keyboard'
    print('\r? ', flush= True, end = '')

    ## A blocking single char read in raw mode. 
    char =
    print('You entered %s\r' % char)
    return char

## Must init curses before calling any functions
## To make sure the terminal returns to its initial settings,
## and to set raw mode and guarantee cleanup on exit. 
print('Curses be gone!')

SQL Order By Count

Try using below Query:

    COUNT(*) AS Total_Count
    Total_Count DESC

Bridged networking not working in Virtualbox under Windows 10

I faced the same problem today after updating the Virtual Box. Got resolved by uninstalling Virtual Box and moving back to old version V5.2.8

Delete all the queues from RabbitMQ?

I tried rabbitmqctl and reset commands but they are very slow.

This is the fastest way I found (replace your username and password):


# Stop on error
set -eo pipefail


curl -sSL -u $USER:$PASSWORD http://localhost:15672/api/queues/%2f/ | jq '.[].name' | sed 's/"//g' | xargs -L 1 -I@ curl -XDELETE -sSL -u $USER:$PASSWORD http://localhost:15672/api/queues/%2f/@
# To also delete exchanges uncomment next line
# curl -sSL -u $USER:$PASSWORD http://localhost:15672/api/exchanges/%2f/ | jq '.[].name' | sed 's/"//g' | xargs -L 1 -I@ curl -XDELETE -sSL -u $USER:$PASSWORD http://localhost:15672/api/exchanges/%2f/@

Note: This only works with the default vhost /

Google Maps Android API v2 - Interactive InfoWindow (like in original android google maps)

Just a speculation, I have not enough experience to try it... )-:

Since GoogleMap is a fragment, it should be possible to catch marker onClick event and show custom fragment view. A map fragment will be still visible on the background. Does anybody tried it? Any reason why it could not work?

The disadvantage is that map fragment would be freezed on backgroud, until a custom info fragment return control to it.

Using request.setAttribute in a JSP page

If you want your requests to persists try this:

example: on your JSP or servlet page

request.getSession().setAttribute("SUBFAMILY", subFam);

and on any receiving page use the below lines to retrieve your session and data:

SubFamily subFam = (SubFamily)request.getSession().getAttribute("SUBFAMILY");

document.getElementByID is not a function

I've modified your script to work with jQuery, if you wish to do so.

    //To add a task when the user hits the return key
          if(evt.keyCode == 13)
             add_task($(this), evt);
    //To add a task when the user clicks on the submit button

function add_task(textBox, evt){
  var taskText = textBox.val();
  $("<li />").text(taskText).appendTo("#tasks");

Sorting a list using Lambda/Linq to objects

If you get sort column name and sort direction as string and don't want to use switch or if\else syntax to determine column, then this example may be interesting for you:

private readonly Dictionary<string, Expression<Func<IuInternetUsers, object>>> _sortColumns = 
        new Dictionary<string, Expression<Func<IuInternetUsers, object>>>()
        { nameof(ContactSearchItem.Id),             c => c.Id },
        { nameof(ContactSearchItem.FirstName),      c => c.FirstName },
        { nameof(ContactSearchItem.LastName),       c => c.LastName },
        { nameof(ContactSearchItem.Organization),   c => c.Company.Company },
        { nameof(ContactSearchItem.CustomerCode),   c => c.Company.Code },
        { nameof(ContactSearchItem.Country),        c => c.CountryNavigation.Code },
        { nameof(ContactSearchItem.City),           c => c.City },
        { nameof(ContactSearchItem.ModifiedDate),   c => c.ModifiedDate },

    private IQueryable<IuInternetUsers> SetUpSort(IQueryable<IuInternetUsers> contacts, string sort, string sortDir)
        if (string.IsNullOrEmpty(sort))
            sort = nameof(ContactSearchItem.Id);

        _sortColumns.TryGetValue(sort, out var sortColumn);
        if (sortColumn == null)
            sortColumn = c => c.Id;

        if (string.IsNullOrEmpty(sortDir) || sortDir == SortDirections.AscendingSort)
            contacts = contacts.OrderBy(sortColumn);
            contacts = contacts.OrderByDescending(sortColumn);

        return contacts;

Solution based on using Dictionary that connects needed for sort column via Expression> and its key string.

How to disable a particular checkstyle rule for a particular line of code?

If you prefer to use annotations to selectively silence rules, this is now possible using the @SuppressWarnings annotation, starting with Checkstyle 5.7 (and supported by the Checkstyle Maven Plugin 2.12+).

First, in your checkstyle.xml, add the SuppressWarningsHolder module to the TreeWalker:

<module name="TreeWalker">
    <!-- Make the @SuppressWarnings annotations available to Checkstyle -->
    <module name="SuppressWarningsHolder" />

Next, enable the SuppressWarningsFilter there (as a sibling to TreeWalker):

<!-- Filter out Checkstyle warnings that have been suppressed with the @SuppressWarnings annotation -->
<module name="SuppressWarningsFilter" />

<module name="TreeWalker">

Now you can annotate e.g. the method you want to exclude from a certain Checkstyle rule:

public boolean equals(Object obj) {
    // very long auto-generated equals() method

The checkstyle: prefix in the argument to @SuppressWarnings is optional, but I like it as a reminder where this warning came from. The rule name must be lowercase.

Lastly, if you're using Eclipse, it will complain about the argument being unknown to it:

Unsupported @SuppressWarnings("checkstyle:methodlength")

You can disable this Eclipse warning in the preferences if you like:

  --> Compiler
  --> Errors/Warnings
  --> Annotations
  --> Unhandled token in '@SuppressWarnings': set to 'Ignore'

What causes signal 'SIGILL'?

Make sure that all functions with non-void return type have a return statement.

While some compilers automatically provide a default return value, others will send a SIGILL or SIGTRAP at runtime when trying to leave a function without a return value.

HRESULT: 0x800A03EC on Worksheet.range

Just FYI, got the error trying to apply row style....

wSheet.Rows(y).Style = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red)

HTTP Error 500.22 - Internal Server Error (An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode.)

Personnaly I encountered this issue while migrating a IIS6 website into IIS7, in order to fix this issue I used this command line :
%windir%\System32\inetsrv\appcmd migrate config "MyWebSite\"
Make sure to backup your web.config

In SSRS, why do I get the error "item with same key has already been added" , when I'm making a new report?

SSRS will not accept duplicated columns so ensure that your query or store procedure is returning unique column names.

android - setting LayoutParams programmatically

int dp1 = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 1,

tv.setLayoutParams(new ViewGroup.LayoutParams(
dp1 * 100)); // if you want to set layout height to 100dp


How do I get JSON data from RESTful service using Python?

Well first of all I think rolling out your own solution for this all you need is urllib2 or httplib2 . Anyways in case you do require a generic REST client check this out .

However i think the feature set of the library will not work for most web services because they shall probably using oauth etc .. . Also I don't like the fact that it is written over httplib which is a pain as compared to httplib2 still should work for you if you don't have to handle a lot of redirections etc ..

Check if URL has certain string with PHP

Try something like this. The first row builds your URL and the rest check if it contains the word "car".

$url = 'http://' . $_SERVER['SERVER_NAME'] . $_SERVER['REQUEST_URI'];

if (strpos($url,'car') !== false) {
    echo 'Car exists.';
} else {
    echo 'No cars.';

How do I view the Explain Plan in Oracle Sql developer?

We use Oracle PL/SQL Developer(Version 12.0.7). And we use F5 button to view the explain plan.

Turning Sonar off for certain code

I recommend you try to suppress specific warnings by using @SuppressWarnings("squid:S2078").

For suppressing multiple warnings you can do it like this @SuppressWarnings({"squid:S2078", "squid:S2076"})

There is also the //NOSONAR comment that tells SonarQube to ignore all errors for a specific line.

Finally if you have the proper rights for the user interface you can issue a flag as a false positive directly from the interface.

The reason why I recommend suppression of specific warnings is that it's a better practice to block a specific issue instead of using //NOSONAR and risk a Sonar issue creeping in your code by accident.

You can read more about this in the FAQ

Edit: 6/30/16 SonarQube is now called SonarLint

In case you are wondering how to find the squid number. Just click on the Sonar message (ex. Remove this method to simply inherit it.) and the Sonar issue will expand.

On the bottom left it will have the squid number (ex. squid:S1185 Maintainability > Understandability)

So then you can suppress it by @SuppressWarnings("squid:S1185")

Remove trailing comma from comma-separated string

public static String removeExtraCommas(String entry) {
        return null;

    String ret="";
    String arr[]=entry.split(",");
    boolean start=true;
    for(String str:arr) {
        if(!"".equalsIgnoreCase(str)) {
            if(start) {
            else {
    return ret;


Add a new line to a text file in MS-DOS

echo "text to echo" > file.txt

How to automatically add user account AND password with a Bash script?

I know I'm coming at this years later, but I can't believe no one suggested usermod.

usermod --password `perl -e "print crypt('password','sa');"` root

Hell, just in case someone wants to do this on an older HPUX you can use usermod.sam.

/usr/sam/lbin/usermod.sam -F -p `perl -e "print crypt('password','sa');"` username

The -F is only needed if the person executing the script is the current user. Of course you don't need to use Perl to create the hash. You could use openssl or many other commands in its place.

How to compare different branches in Visual Studio Code

2019 answer

Here is the step by step guide:

  1. Install the GitLens extension: GitLens
  2. The GitLens icon will show up in nav bar. Click on it.

    Git lens icon

  3. Click on compare

    Enter image description here

  4. Select branches to compare

    enter image description here

  5. Now you can see the difference. You can select any file for which you want to see the diff for.

    Enter image description here

Using Server.MapPath() inside a static field in ASP.NET MVC

I think you can try this for calling in from a class


*----------------Sorry I oversight, for static function already answered the question by adrift*



I got exception while using System.Web.Hosting.HostingEnvironment.MapPath("~/SignatureImages/");

Ex details : System.ArgumentException: The relative virtual path 'SignatureImages' is not allowed here. at System.Web.VirtualPath.FailIfRelativePath()

Solution (tested in static webmethod)

System.Web.HttpContext.Current.Server.MapPath("~/SignatureImages/"); Worked

What does ${} (dollar sign and curly braces) mean in a string in Javascript?

As mentioned in a comment above, you can have expressions within the template strings/literals. Example:

const one = 1;_x000D_
const two = 2;_x000D_
const result = `One add two is ${one + two}`;_x000D_
console.log(result); // output: One add two is 3

Exception: Unexpected end of ZLIB input stream

You have to call close() on the GZIPOutputStream before you attempt to read it. The final bytes of the file will only be written when the file is actually closed. (This is irrespective of any explicit buffering in the output stack. The stream only knows to compress and write the last bytes when you tell it to close. A flush() probably won't help ... though calling finish() instead of close() should work. Look at the javadocs.)

Here's the correct code (in Java);

package test;


public class GZipTest {

    public static void main(String[] args) throws
                FileNotFoundException, IOException {
        String name = "/tmp/test";
        GZIPOutputStream gz = new GZIPOutputStream(new FileOutputStream(name));
        gz.close();       // Remove this to reproduce the reported bug
        System.out.println(new GZIPInputStream(new FileInputStream(name)).read());

(I've not implemented resource management or exception handling / reporting properly as they are not relevant to the purpose of this code. Don't treat this as an example of "good code".)

PLS-00201 - identifier must be declared

The procedure name should be in caps while creating procedure in database. You may use small letters for your procedure name while calling from Java class like:

String getDBUSERByUserIdSql = "{call getDBUSERByUserId(?,?,?,?)}";

In database the name of procedure should be:

GETDBUSERBYUSERID    -- (all letters in caps only)

This serves as one of the solutions for this problem.

How to "crop" a rectangular image into a square with CSS?

Assuming they do not have to be in IMG tags...


<div class="thumb1">


.thumb1 { 
  background: url(blah.jpg) 50% 50% no-repeat; /* 50% 50% centers image in div */
  width: 250px;
  height: 250px;

.thumb1:hover { YOUR HOVER STYLES HERE }

EDIT: If the div needs to link somewhere just adjust HTML and Styles like so:


<div class="thumb1">
<a href="#">Link</a>


.thumb1 { 
  background: url(blah.jpg) 50% 50% no-repeat; /* 50% 50% centers image in div */
  width: 250px;
  height: 250px;

.thumb1 a {
  display: block;
  width: 250px;
  height: 250px;

.thumb1 a:hover { YOUR HOVER STYLES HERE }

Note this could also be modified to be responsive, for example % widths and heights etc.

How can I format a list to print each element on a separate line in python?

Use str.join:

In [27]: mylist = ['10', '12', '14']

In [28]: print '\n'.join(mylist)

When to use "new" and when not to, in C++?

New is always used to allocate dynamic memory, which then has to be freed.

By doing the first option, that memory will be automagically freed when scope is lost.

Point p1 = Point(0,0); //This is if you want to be safe and don't want to keep the memory outside this function.

Point* p2 = new Point(0, 0); //This must be freed manually. with...
delete p2;

PHP: Convert any string to UTF-8 without knowing the original character set, or at least try

You've probably tried this to but why not just use the mb_convert_encoding function? It will attempt to auto-detect char set of the text provided or you can pass it a list.

Also, I tried to run:

$text = "fiancée";
echo mb_convert_encoding($text, "UTF-8");
echo "<br/><br/>";
echo iconv(mb_detect_encoding($text), "UTF-8", $text);

and the results are the same for both. How do you see that your text is truncated to 'fianc'? is it in the DB or in a browser?

Get protocol + host name from URL

I know it's an old question, but I too encountered it today. Solved this with an one-liner:

import re
result = re.sub(r'(.*://)?([^/?]+).*', '\g<1>\g<2>', url)

access denied for user @ 'localhost' to database ''

Try this: Adding users to MySQL

You need grant privileges to the user if you want external acess to database(ie. web pages).

How to set "style=display:none;" using jQuery's attr method?

var display =  $("#msform").css("display");
        $("#msform").attr("style", "display:none");

Iterate over array of objects in Typescript

In Typescript and ES6 you can also use for..of:

for (var product of products) {

which will be transcoded to javascript:

for (var _i = 0, products_1 = products; _i < products_1.length; _i++) {
    var product = products_1[_i];

MySQL wait_timeout Variable - GLOBAL vs SESSION

SHOW SESSION VARIABLES LIKE "wait_timeout"; -- 28800
SHOW GLOBAL VARIABLES LIKE "wait_timeout"; -- 28800

At first, wait_timeout = 28800 which is the default value. To change the session value, you need to set the global variable because the session variable is read-only.

SET @@GLOBAL.wait_timeout=300

After you set the global variable, the session variable automatically grabs the value.

SHOW SESSION VARIABLES LIKE "wait_timeout"; -- 300
SHOW GLOBAL VARIABLES LIKE "wait_timeout"; -- 300

Next time when the server restarts, the session variables will be set to the default value i.e. 28800.

P.S. I m using MySQL 5.6.16

How to overplot a line on a scatter plot in python?

You can use this tutorial by Adarsh Menon

This way is the easiest I found and it basically looks like:

import numpy as np
import matplotlib.pyplot as plt  # To visualize
import pandas as pd  # To read data
from sklearn.linear_model import LinearRegression
data = pd.read_csv('data.csv')  # load data set
X = data.iloc[:, 0].values.reshape(-1, 1)  # values converts it into a numpy array
Y = data.iloc[:, 1].values.reshape(-1, 1)  # -1 means that calculate the dimension of rows, but have 1 column
linear_regressor = LinearRegression()  # create object for the class, Y)  # perform linear regression
Y_pred = linear_regressor.predict(X)  # make predictions
plt.scatter(X, Y)
plt.plot(X, Y_pred, color='red')

Iterate over each line in a string in PHP

Kyril's answer is best considering you need to be able to handle newlines on different machines.

"I'm mostly looking for useful PHP functions, not an algorithm for how to do it. Any suggestions?"

I use these a lot:

  • explode() can be used to split a string into an array, given a single delimiter.
  • implode() is explode's counterpart, to go from array back to string.

Virtual member call in a constructor

In order to answer your question, consider this question: what will the below code print out when the Child object is instantiated?

class Parent
    public Parent()

    protected virtual void DoSomething() 

class Child : Parent
    private string foo;

    public Child() 
        foo = "HELLO"; 

    protected override void DoSomething()
        Console.WriteLine(foo.ToLower()); //NullReferenceException!?!

The answer is that in fact a NullReferenceException will be thrown, because foo is null. An object's base constructor is called before its own constructor. By having a virtual call in an object's constructor you are introducing the possibility that inheriting objects will execute code before they have been fully initialized.

how to create 100% vertical line in css

When I tested this, I tried using the position property and it worked perfectly.


<div class="main">
 <div class="body">
 //add content here


 position: relative;

 position: absolute;
 height: 100%;

How to encode the filename parameter of Content-Disposition header in HTTP?

I know this is an old post but it is still very relevant. I have found that modern browsers support rfc5987, which allows utf-8 encoding, percentage encoded (url-encoded). Then Naïve file.txt becomes:

Content-Disposition: attachment; filename*=UTF-8''Na%C3%AFve%20file.txt

Safari (5) does not support this. Instead you should use the Safari standard of writing the file name directly in your utf-8 encoded header:

Content-Disposition: attachment; filename=Naïve file.txt

IE8 and older don't support it either and you need to use the IE standard of utf-8 encoding, percentage encoded:

Content-Disposition: attachment; filename=Na%C3%AFve%20file.txt

In ASP.Net I use the following code:

string contentDisposition;
if (Request.Browser.Browser == "IE" && (Request.Browser.Version == "7.0" || Request.Browser.Version == "8.0"))
    contentDisposition = "attachment; filename=" + Uri.EscapeDataString(fileName);
else if (Request.Browser.Browser == "Safari")
    contentDisposition = "attachment; filename=" + fileName;
    contentDisposition = "attachment; filename*=UTF-8''" + Uri.EscapeDataString(fileName);
Response.AddHeader("Content-Disposition", contentDisposition);

I tested the above using IE7, IE8, IE9, Chrome 13, Opera 11, FF5, Safari 5.

Update November 2013:

Here is the code I currently use. I still have to support IE8, so I cannot get rid of the first part. It turns out that browsers on Android use the built in Android download manager and it cannot reliably parse file names in the standard way.

string contentDisposition;
if (Request.Browser.Browser == "IE" && (Request.Browser.Version == "7.0" || Request.Browser.Version == "8.0"))
    contentDisposition = "attachment; filename=" + Uri.EscapeDataString(fileName);
else if (Request.UserAgent != null && Request.UserAgent.ToLowerInvariant().Contains("android")) // android built-in download manager (all browsers on android)
    contentDisposition = "attachment; filename=\"" + MakeAndroidSafeFileName(fileName) + "\"";
    contentDisposition = "attachment; filename=\"" + fileName + "\"; filename*=UTF-8''" + Uri.EscapeDataString(fileName);
Response.AddHeader("Content-Disposition", contentDisposition);

The above now tested in IE7-11, Chrome 32, Opera 12, FF25, Safari 6, using this filename for download: ??abcABCæøåÆØÅäöüïëêîâéíáóúýñ½§!#¤%&()=`@£$€{[]}+´¨^~'-_,;.txt

On IE7 it works for some characters but not all. But who cares about IE7 nowadays?

This is the function I use to generate safe file names for Android. Note that I don't know which characters are supported on Android but that I have tested that these work for sure:

private static readonly Dictionary<char, char> AndroidAllowedChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ._-+,@£$€!½§~'=()[]{}0123456789".ToDictionary(c => c);
private string MakeAndroidSafeFileName(string fileName)
    char[] newFileName = fileName.ToCharArray();
    for (int i = 0; i < newFileName.Length; i++)
        if (!AndroidAllowedChars.ContainsKey(newFileName[i]))
            newFileName[i] = '_';
    return new string(newFileName);

@TomZ: I tested in IE7 and IE8 and it turned out that I did not need to escape apostrophe ('). Do you have an example where it fails?

@Dave Van den Eynde: Combining the two file names on one line as according to RFC6266 works except for Android and IE7+8 and I have updated the code to reflect this. Thank you for the suggestion.

@Thilo: No idea about GoodReader or any other non-browser. You might have some luck using the Android approach.

@Alex Zhukovskiy: I don't know why but as discussed on Connect it doesn't seem to work terribly well.

Editing in the Chrome debugger

Now google chrome has introduce new feature. By Using this feature You can edit you code in chrome browse. (Permanent change on code location)

For that Press F12 --> Source Tab -- (right side) --> File System - in that please select your location of code. and then chrome browser will ask you permission and after that code will be sink with green color. and you can modify your code and it will also reflect on you code location (It means it will Permanent change)


How to properly stop the Thread in Java?

Using Thread.interrupt() is a perfectly acceptable way of doing this. In fact, it's probably preferrable to a flag as suggested above. The reason being that if you're in an interruptable blocking call (like Thread.sleep or using java.nio Channel operations), you'll actually be able to break out of those right away.

If you use a flag, you have to wait for the blocking operation to finish and then you can check your flag. In some cases you have to do this anyway, such as using standard InputStream/OutputStream which are not interruptable.

In that case, when a thread is interrupted, it will not interrupt the IO, however, you can easily do this routinely in your code (and you should do this at strategic points where you can safely stop and cleanup)

if (Thread.currentThread().isInterrupted()) {
  // cleanup and stop execution
  // for example a break in a loop

Like I said, the main advantage to Thread.interrupt() is that you can immediately break out of interruptable calls, which you can't do with the flag approach.

How can I delete a service in Windows?

You can use my small service list editor utility Service Manager


You can choose any service > Modify > Delete. Method works immediately, no reboot required.

Executable file: [Download]

Source code: [Download]

Blog post: [BlogLink]

Service editor class: WinServiceUtils.cs

How to change the new TabLayout indicator color and height

Since I can't post a follow-up to android developer's comment, here's an updated answer for anyone else who needs to programmatically set the selected tab indicator color:


Similarly, for height:

tabLayout.setSelectedTabIndicatorHeight((int) (2 * getResources().getDisplayMetrics().density));

These methods were only recently added to revision 23.0.0 of the Support Library, which is why Soheil Setayeshi's answer uses reflection.

Javascript, viewing [object HTMLInputElement]


$("input:text").change(function() {
    var value=$("input:text").val();


$("input:text").change(function() {
    var value=$("input[type=text].selector").val();

note: selector:id,class..

Removing duplicates from rows based on specific columns in an RDD/Spark DataFrame

From your question, it is unclear as-to which columns you want to use to determine duplicates. The general idea behind the solution is to create a key based on the values of the columns that identify duplicates. Then, you can use the reduceByKey or reduce operations to eliminate duplicates.

Here is some code to get you started:

def get_key(x):
    return "{0}{1}{2}".format(x[0],x[2],x[3])

m = x: (get_key(x),x))

Now, you have a key-value RDD that is keyed by columns 1,3 and 4. The next step would be either a reduceByKey or groupByKey and filter. This would eliminate duplicates.

r = m.reduceByKey(lambda x,y: (x))

Simple insecure two-way data "obfuscation"?

Other answers here work fine, but AES is a more secure and up-to-date encryption algorithm. This is a class that I obtained a few years ago to perform AES encryption that I have modified over time to be more friendly for web applications (e,g. I've built Encrypt/Decrypt methods that work with URL-friendly string). It also has the methods that work with byte arrays.

NOTE: you should use different values in the Key (32 bytes) and Vector (16 bytes) arrays! You wouldn't want someone to figure out your keys by just assuming that you used this code as-is! All you have to do is change some of the numbers (must be <= 255) in the Key and Vector arrays (I left one invalid value in the Vector array to make sure you do this...). You can use to generate a new set easily:

Using it is easy: just instantiate the class and then call (usually) EncryptToString(string StringToEncrypt) and DecryptString(string StringToDecrypt) as methods. It couldn't be any easier (or more secure) once you have this class in place.

using System;
using System.Data;
using System.Security.Cryptography;
using System.IO;

public class SimpleAES
    // Change these keys
    private byte[] Key = __Replace_Me__({ 123, 217, 19, 11, 24, 26, 85, 45, 114, 184, 27, 162, 37, 112, 222, 209, 241, 24, 175, 144, 173, 53, 196, 29, 24, 26, 17, 218, 131, 236, 53, 209 });

    // a hardcoded IV should not be used for production AES-CBC code
    // IVs should be unpredictable per ciphertext
    private byte[] Vector = __Replace_Me__({ 146, 64, 191, 111, 23, 3, 113, 119, 231, 121, 2521, 112, 79, 32, 114, 156 });

    private ICryptoTransform EncryptorTransform, DecryptorTransform;
    private System.Text.UTF8Encoding UTFEncoder;

    public SimpleAES()
        //This is our encryption method
        RijndaelManaged rm = new RijndaelManaged();

        //Create an encryptor and a decryptor using our encryption method, key, and vector.
        EncryptorTransform = rm.CreateEncryptor(this.Key, this.Vector);
        DecryptorTransform = rm.CreateDecryptor(this.Key, this.Vector);

        //Used to translate bytes to text and vice versa
        UTFEncoder = new System.Text.UTF8Encoding();

    /// -------------- Two Utility Methods (not used but may be useful) -----------
    /// Generates an encryption key.
    static public byte[] GenerateEncryptionKey()
        //Generate a Key.
        RijndaelManaged rm = new RijndaelManaged();
        return rm.Key;

    /// Generates a unique encryption vector
    static public byte[] GenerateEncryptionVector()
        //Generate a Vector
        RijndaelManaged rm = new RijndaelManaged();
        return rm.IV;

    /// ----------- The commonly used methods ------------------------------    
    /// Encrypt some text and return a string suitable for passing in a URL.
    public string EncryptToString(string TextValue)
        return ByteArrToString(Encrypt(TextValue));

    /// Encrypt some text and return an encrypted byte array.
    public byte[] Encrypt(string TextValue)
        //Translates our text value into a byte array.
        Byte[] bytes = UTFEncoder.GetBytes(TextValue);

        //Used to stream the data in and out of the CryptoStream.
        MemoryStream memoryStream = new MemoryStream();

         * We will have to write the unencrypted bytes to the stream,
         * then read the encrypted result back from the stream.
        #region Write the decrypted value to the encryption stream
        CryptoStream cs = new CryptoStream(memoryStream, EncryptorTransform, CryptoStreamMode.Write);
        cs.Write(bytes, 0, bytes.Length);

        #region Read encrypted value back out of the stream
        memoryStream.Position = 0;
        byte[] encrypted = new byte[memoryStream.Length];
        memoryStream.Read(encrypted, 0, encrypted.Length);

        //Clean up.

        return encrypted;

    /// The other side: Decryption methods
    public string DecryptString(string EncryptedString)
        return Decrypt(StrToByteArray(EncryptedString));

    /// Decryption when working with byte arrays.    
    public string Decrypt(byte[] EncryptedValue)
        #region Write the encrypted value to the decryption stream
        MemoryStream encryptedStream = new MemoryStream();
        CryptoStream decryptStream = new CryptoStream(encryptedStream, DecryptorTransform, CryptoStreamMode.Write);
        decryptStream.Write(EncryptedValue, 0, EncryptedValue.Length);

        #region Read the decrypted value from the stream.
        encryptedStream.Position = 0;
        Byte[] decryptedBytes = new Byte[encryptedStream.Length];
        encryptedStream.Read(decryptedBytes, 0, decryptedBytes.Length);
        return UTFEncoder.GetString(decryptedBytes);

    /// Convert a string to a byte array.  NOTE: Normally we'd create a Byte Array from a string using an ASCII encoding (like so).
    //      System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
    //      return encoding.GetBytes(str);
    // However, this results in character values that cannot be passed in a URL.  So, instead, I just
    // lay out all of the byte values in a long string of numbers (three per - must pad numbers less than 100).
    public byte[] StrToByteArray(string str)
        if (str.Length == 0)
            throw new Exception("Invalid string value in StrToByteArray");

        byte val;
        byte[] byteArr = new byte[str.Length / 3];
        int i = 0;
        int j = 0;
            val = byte.Parse(str.Substring(i, 3));
            byteArr[j++] = val;
            i += 3;
        while (i < str.Length);
        return byteArr;

    // Same comment as above.  Normally the conversion would use an ASCII encoding in the other direction:
    //      System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
    //      return enc.GetString(byteArr);    
    public string ByteArrToString(byte[] byteArr)
        byte val;
        string tempStr = "";
        for (int i = 0; i <= byteArr.GetUpperBound(0); i++)
            val = byteArr[i];
            if (val < (byte)10)
                tempStr += "00" + val.ToString();
            else if (val < (byte)100)
                tempStr += "0" + val.ToString();
                tempStr += val.ToString();
        return tempStr;

Jquery Ajax beforeSend and success,error & complete

It's actually much easier with jQuery's promise API:

            type: "GET",
            url: requestURL,
        ).then((success) =>
        ).failure((failureResponse) =>

Alternatively, you can pass in of bind functions to each result callback; the order of parameters is: (success, failure). So long as you specify a function with at least 1 parameter, you get access to the response. So, for example, if you wanted to check the response text, you could simply do:

            type: "GET",
            url: @get("url") + "logout",
            beforeSend: (xhr) -> xhr.setRequestHeader("token", currentToken)
        ).failure((response) -> console.log "Request was unauthorized" if response.status is 401

How to run Pip commands from CMD

In my case I was trying to install Flask. I wanted to run pip install Flask command. But when I open command prompt it I goes to C:\Users[user]>. If you give here it will say pip is not recognized. I did below steps

On your desktop right click Computer and select Properties

Select Advanced Systems Settings

In popup which you see select Advanced tab and then click Environment Variables

In popup double click PATH and from popup copy variable value for variable name PATH and paste the variable value in notepad or so and look for an entry for Python.

In my case it was C:\Users\[user]\AppData\Local\Programs\Python\Python36-32

Now in my command prompt i moved to above location and gave pip install Flask

enter image description here

"Cannot open include file: 'config-win.h': No such file or directory" while installing mysql-python

Download the version of Connector from For my case I had installed 64 bit of connector and my python was 32 bit. So I had to copy MySQL from program files to Program Files(86)

Private properties in JavaScript ES6 classes

It is possible to have private methods in classes using WeakMap.

According to MDN web docs:

The WeakMap object is a collection of key/value pairs in which the keys are objects only and the values can be arbitrary values.

The object references in the keys are held weakly, meaning that they are a target of garbage collection (GC) if there is no other reference to the object anymore.

And this is an example of creating Queue data structure with a private member _items which holds an array.

const _items = new WeakMap();

class Queue {    
    constructor() {
        _items.set(this, []);

    enqueue( item) {

    get count() {
        return _items.get(this).length;        

    peek() {
        const anArray = _items.get(this);
        if( anArray.length == 0)
            throw new Error('There are no items in array!');

        if( anArray.length > 0)
            return anArray[0];

    dequeue() {        
        const anArray = _items.get(this);
        if( anArray.length == 0)
            throw new Error('There are no items in array!');

        if( anArray.length > 0)
            return anArray.splice(0, 1)[0];

An example of using:

const c = new Queue();

Private member _items is hided and cannot be seen in properties or methods of an Queue object:

enter image description here

However, private member _items in the Queue object can be reached using this way:

const anArray = _items.get(this);

Tomcat 404 error: The origin server did not find a current representation for the target resource or is not willing to disclose that one exists

Problem solved, I've not added the index.html. Which is point out in the web.xml

enter image description here

Note: a project may have more than one web.xml file.

if there are another web.xml in


Then you might need to add another index (this time index.jsp) to


How do you connect to multiple MySQL databases on a single webpage?

    // Sapan Mohanty
    // Skype:sapan.mohannty
    $oldData = mysql_connect('localhost', 'DBUSER', 'DBPASS');
    echo mysql_error();
    $NewData = mysql_connect('localhost', 'DBUSER', 'DBPASS');
    echo mysql_error();
    mysql_select_db('OLDDBNAME', $oldData );
    mysql_select_db('NEWDBNAME', $NewData );
    $getAllTablesName    = "SELECT table_name FROM information_schema.tables WHERE table_type = 'base table'";
    $getAllTablesNameExe = mysql_query($getAllTablesName);
    //echo mysql_error();
    while ($dataTableName = mysql_fetch_object($getAllTablesNameExe)) {

        $oldDataCount       = mysql_query('select count(*) as noOfRecord from ' . $dataTableName->table_name, $oldData);
        $oldDataCountResult = mysql_fetch_object($oldDataCount);

        $newDataCount       = mysql_query('select count(*) as noOfRecord from ' . $dataTableName->table_name, $NewData);
        $newDataCountResult = mysql_fetch_object($newDataCount);

        if ( $oldDataCountResult->noOfRecord != $newDataCountResult->noOfRecord ) {
            echo "<br/><b>" . $dataTableName->table_name . "</b>";
            echo " | Old: " . $oldDataCountResult->noOfRecord;
            echo " | New: " . $newDataCountResult->noOfRecord;

            if ($oldDataCountResult->noOfRecord < $newDataCountResult->noOfRecord) {
                echo " | <font color='green'>*</font>";

            } else {
                echo " | <font color='red'>*</font>";

            echo "<br/>----------------------------------------";



How to rotate a div using jQuery

EDIT: Updated for jQuery 1.8

Since jQuery 1.8 browser specific transformations will be added automatically. jsFiddle Demo

var rotation = 0;

jQuery.fn.rotate = function(degrees) {
    $(this).css({'transform' : 'rotate('+ degrees +'deg)'});
    return $(this);

$('.rotate').click(function() {
    rotation += 5;

EDIT: Added code to make it a jQuery function.

For those of you who don't want to read any further, here you go. For more details and examples, read on. jsFiddle Demo.

var rotation = 0;

jQuery.fn.rotate = function(degrees) {
    $(this).css({'-webkit-transform' : 'rotate('+ degrees +'deg)',
                 '-moz-transform' : 'rotate('+ degrees +'deg)',
                 '-ms-transform' : 'rotate('+ degrees +'deg)',
                 'transform' : 'rotate('+ degrees +'deg)'});
    return $(this);

$('.rotate').click(function() {
    rotation += 5;

EDIT: One of the comments on this post mentioned jQuery Multirotation. This plugin for jQuery essentially performs the above function with support for IE8. It may be worth using if you want maximum compatibility or more options. But for minimal overhead, I suggest the above function. It will work IE9+, Chrome, Firefox, Opera, and many others.

Bobby... This is for the people who actually want to do it in the javascript. This may be required for rotating on a javascript callback.

Here is a jsFiddle.

If you would like to rotate at custom intervals, you can use jQuery to manually set the css instead of adding a class. Like this! I have included both jQuery options at the bottom of the answer.


<div class="rotate">
    <h1>Rotatey text</h1>


/* Totally for style */
.rotate {
    background: #F02311;
    color: #FFF;
    width: 200px;
    height: 200px;
    text-align: center;
    font: normal 1em Arial;
    position: relative;
    top: 50px;
    left: 50px;

/* The real code */
.rotated {
    -webkit-transform: rotate(45deg);  /* Chrome, Safari 3.1+ */
    -moz-transform: rotate(45deg);  /* Firefox 3.5-15 */
    -ms-transform: rotate(45deg);  /* IE 9 */
    -o-transform: rotate(45deg);  /* Opera 10.50-12.00 */
    transform: rotate(45deg);  /* Firefox 16+, IE 10+, Opera 12.10+ */


Make sure these are wrapped in $(document).ready

$('.rotate').click(function() {

Custom intervals

var rotation = 0;
$('.rotate').click(function() {
    rotation += 5;
    $(this).css({'-webkit-transform' : 'rotate('+ rotation +'deg)',
                 '-moz-transform' : 'rotate('+ rotation +'deg)',
                 '-ms-transform' : 'rotate('+ rotation +'deg)',
                 'transform' : 'rotate('+ rotation +'deg)'});

Are multi-line strings allowed in JSON?

While not standard, I found that some of the JSON libraries have options to support multiline Strings. I am saying this with the caveat, that this will hurt your interoperability.

However in the specific scenario I ran into, I needed to make a config file that was only ever used by one system readable and manageable by humans. And opted for this solution in the end.

Here is how this works out on Java with Jackson:

JsonMapper mapper = JsonMapper.builder()

SQL join on multiple columns in same tables

You want to join on condition 1 AND condition 2, so simply use the AND keyword as below

ON a.userid = b.sourceid AND a.listid = b.destinationid;

How to iterate through an ArrayList of Objects of ArrayList of Objects?

for (Bullet bullet : gunList.get(2).getBullet()) System.out.println(bullet);

PHP function to build query string from array

Here's a simple php4-friendly implementation:

* Builds an http query string.
* @param array $query  // of key value pairs to be used in the query
* @return string       // http query string.
function build_http_query( $query ){

    $query_array = array();

    foreach( $query as $key => $key_value ){

        $query_array[] = urlencode( $key ) . '=' . urlencode( $key_value );


    return implode( '&', $query_array );


What is logits, softmax and softmax_cross_entropy_with_logits?

Logits simply means that the function operates on the unscaled output of earlier layers and that the relative scale to understand the units is linear. It means, in particular, the sum of the inputs may not equal 1, that the values are not probabilities (you might have an input of 5).

tf.nn.softmax produces just the result of applying the softmax function to an input tensor. The softmax "squishes" the inputs so that sum(input) = 1: it's a way of normalizing. The shape of output of a softmax is the same as the input: it just normalizes the values. The outputs of softmax can be interpreted as probabilities.

a = tf.constant(np.array([[.1, .3, .5, .9]]))
[[ 0.16838508  0.205666    0.25120102  0.37474789]]

In contrast, tf.nn.softmax_cross_entropy_with_logits computes the cross entropy of the result after applying the softmax function (but it does it all together in a more mathematically careful way). It's similar to the result of:

sm = tf.nn.softmax(x)
ce = cross_entropy(sm)

The cross entropy is a summary metric: it sums across the elements. The output of tf.nn.softmax_cross_entropy_with_logits on a shape [2,5] tensor is of shape [2,1] (the first dimension is treated as the batch).

If you want to do optimization to minimize the cross entropy AND you're softmaxing after your last layer, you should use tf.nn.softmax_cross_entropy_with_logits instead of doing it yourself, because it covers numerically unstable corner cases in the mathematically right way. Otherwise, you'll end up hacking it by adding little epsilons here and there.

Edited 2016-02-07: If you have single-class labels, where an object can only belong to one class, you might now consider using tf.nn.sparse_softmax_cross_entropy_with_logits so that you don't have to convert your labels to a dense one-hot array. This function was added after release 0.6.0.

"int cannot be dereferenced" in Java

id is of primitive type int and not an Object. You cannot call methods on a primitive as you are doing here :


Try replacing this:

        if (id.equals(list[pos].getItemNumber())){ //Getting error on "equals"


        if (id == list[pos].getItemNumber()){ //Getting error on "equals"

Static method in a generic class?

Since static variables are shared by all instances of the class. For example if you are having following code

class Class<T> {
  static void doIt(T object) {
    // using T here 

T is available only after an instance is created. But static methods can be used even before instances are available. So, Generic type parameters cannot be referenced inside static methods and variables

Python's time.clock() vs. time.time() accuracy?

clock() -> floating point number

Return the CPU time or real time since the start of the process or since the first call to clock(). This has as much precision as the system records.

time() -> floating point number

Return the current time in seconds since the Epoch. Fractions of a second may be present if the system clock provides them.

Usually time() is more precise, because operating systems do not store the process running time with the precision they store the system time (ie, actual time)

cannot find module "lodash"

Be sure to install lodash in the required folder. This is probably your C:\gwsk directory.

If that folder has a package.json file, it is also best to add --save behind the install command.

$ npm install lodash --save

The package.json file holds information about the project, but to keep it simple, it holds your project dependencies.

The save command will add the installed module to the project dependencies.

If the package.json file exists, and if it contains the lodash dependency you could try to remove the node_modules folder and run following command:

$ npm cache clean    
$ npm install

The first command will clean the npm cache. (just to be sure) The second command will install all (missing) dependencies of the project.

Hope this helps you understand the node package manager a little bit more.

PHP Include for HTML?

I have a similar issue. It appears that PHP does not like php code inside included file. In your case solution is quite simple. Remove php code from navbar.php, simply leave plain HTML in it and it will work.

How do I center text vertically and horizontally in Flutter?

maybe u want to provide the same width and height for 2 container

            width: size.width * 0.30, height: size.height * 0.4,
            decoration: BoxDecoration(
              borderRadius: BorderRadius.circular(6)
            child: Center(
              child: Text(categoryName, textAlign:, style: TextStyle(
                fontWeight: FontWeight.bold,
                fontSize: 17,
                color: Colors.white,

Arrays in type script

A cleaner way to do this:

class Book {
    public Title: string;
    public Price: number;
    public Description: string;

    constructor(public BookId: number, public Author: string){}


var bks: Book[] = [
    new Book(1, "vamsee")

How do I get the path of a process in Unix / Linux

Find the path to a process name

# @author Lukas Gottschall
PID=`ps aux | grep precessname | grep -v grep | awk '{ print $2 }'`
PATH=`ls -ald --color=never /proc/$PID/exe | awk '{ print $10 }'`
echo $PATH

MySQL: ALTER TABLE if column not exists

Add field if not exist:

CALL addFieldIfNotExists ('settings', 'multi_user', 'TINYINT(1) NOT NULL DEFAULT 1');

addFieldIfNotExists code:




CREATE FUNCTION isFieldExisting (table_name_IN VARCHAR(100), field_name_IN VARCHAR(100)) 
    AND TABLE_NAME = table_name_IN 
    AND COLUMN_NAME = field_name_IN

CREATE PROCEDURE addFieldIfNotExists (
    IN table_name_IN VARCHAR(100)
    , IN field_name_IN VARCHAR(100)
    , IN field_definition_IN VARCHAR(100)

    SET @isFieldThere = isFieldExisting(table_name_IN, field_name_IN);
    IF (@isFieldThere = 0) THEN

        SET @ddl = CONCAT('ALTER TABLE ', table_name_IN);
        SET @ddl = CONCAT(@ddl, ' ', 'ADD COLUMN') ;
        SET @ddl = CONCAT(@ddl, ' ', field_name_IN);
        SET @ddl = CONCAT(@ddl, ' ', field_definition_IN);

        PREPARE stmt FROM @ddl;
        EXECUTE stmt;

    END IF;


.prop() vs .attr()

Gently reminder about using prop(), example:

if ($("#checkbox1").prop('checked')) {
    isDelete = 1;
} else {
    isDelete = 0;

The function above is used to check if checkbox1 is checked or not, if checked: return 1; if not: return 0. Function prop() used here as a GET function.

if ($("#checkbox1").prop('checked', true)) {
    isDelete = 1;
} else {
    isDelete = 0;

The function above is used to set checkbox1 to be checked and ALWAYS return 1. Now function prop() used as a SET function.

Don't mess up.

P/S: When I'm checking Image src property. If the src is empty, prop return the current URL of the page (wrong), and attr return empty string (right).

SQL Server NOLOCK and joins

I won't address the READ UNCOMMITTED argument, just your original question.

Yes, you need WITH(NOLOCK) on each table of the join. No, your queries are not the same.

Try this exercise. Begin a transaction and insert a row into table1 and table2. Don't commit or rollback the transaction yet. At this point your first query will return successfully and include the uncommitted rows; your second query won't return because table2 doesn't have the WITH(NOLOCK) hint on it.

File upload from <input type="file">

Try this small lib, works with Angular 5.0.0

Quickstart example with ng2-file-upload 1.3.0:

User clicks custom button, which triggers upload dialog from hidden input type="file" , uploading started automatically after selecting single file.


import {FileUploadModule} from "ng2-file-upload";


  <button mat-button onclick="document.getElementById('myFileInputField').click()" >
    Select and upload file
  <input type="file" id="myFileInputField" ng2FileSelect [uploader]="uploader" style="display:none">


import {FileUploader} from 'ng2-file-upload';
uploader: FileUploader;
constructor() {
   this.uploader = new FileUploader({url: "/your-api/some-endpoint"});
   this.uploader.onErrorItem = item => {
       console.error("Failed to upload");
   this.uploader.onCompleteItem = (item, response) => {"Successfully uploaded");

       // (Optional) Parsing of response
       let responseObject = JSON.parse(response) as MyCustomClass;


   // Asks uploader to start upload file automatically after selecting file
  this.uploader.onAfterAddingFile = fileItem => this.uploader.uploadAll();

private clearUploadField(): void {
    .value = "";

Alternative lib, works in Angular 4.2.4, but requires some workarounds to adopt to Angular 5.0.0

How to create a JSON object

You could json encode a generic object.

$post_data = new stdClass();
$post_data->item = new stdClass();
$post_data->item->item_type_id = $item_type;
$post_data->item->string_key = $string_key;
$post_data->item->string_value = $string_value;
$post_data->item->string_extra = $string_extra;
$post_data->item->is_public = $public;
$post_data->item->is_public_for_contacts = $public_contacts;
echo json_encode($post_data);

Converting DateTime format using razor

Below code will help you

@Html.Label(@item.Date.Value.ToString("dd - M - yy"))

Loop through columns and add string lengths as new columns

You need to use [[, the programmatic equivalent of $. Otherwise, for example, when i is col1, R will look for df$i instead of df$col1.

for(i in names(df)){
  df[[paste(i, 'length', sep="_")]] <- str_length(df[[i]])

How can I detect the touch event of an UIImageView?

I've been on different threads on the past few hours trying to find a solution for my problem, to no avail. I see that many developers share this problem, and I think people here know about this. I have multiple images inside a UIScrollView, trying to get tap events on them.

I am not getting any events from an UIImangeView, but I do get an event from a similar UILable with very similar parameters I am setting to it. Under iOS 5.1.

I have already done the following:

  1. set setUserInteractionEnabled to YES for both `UIImageView and parent view .
  2. set setMultipleTouchEnabled to YES for UIImageView.
  3. Tried subclassing UIImageView, didn't help any.

Attaching some code below, in this code I initialize both a UIImageView and UILabel, the label works fine in terms of firing events. I tried keeping out irrelevant code.

UIImageView *single_view = [[UIImageView alloc]initWithFrame:CGRectMake(200, 200, 100, 100)];
single_view.image = img;
single_view.layer.zPosition = 4;

UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTapGestureCaptured:)];
[single_view addGestureRecognizer:singleTap];
[single_view setMultipleTouchEnabled:YES];
[single_view setUserInteractionEnabled:YES];
[self.myScrollView addSubview:single_view];
self.myScrollView.userInteractionEnabled = YES;

UILabel *testLabel = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
testLabel.backgroundColor = [UIColor redColor];
[self.myScrollView addSubview:testLabel];
[testLabel addGestureRecognizer:singleTap];
[testLabel setMultipleTouchEnabled:YES];
[testLabel setUserInteractionEnabled:YES];
testLabel.layer.zPosition = 4;

And the method which handles the event:

- (void)singleTapGestureCaptured:(UITapGestureRecognizer *)gesture
    UIView *tappedView = [gesture.view hitTest:[gesture locationInView:gesture.view] withEvent:nil];
    NSLog(@"Touch event on view: %@", [tappedView class]);

As said, the label tap is received.

Handling identity columns in an "Insert Into TABLE Values()" statement?

You have 2 choices:

1) Either specify the column name list (without the identity column).

2) SET IDENTITY_INSERT tablename ON, followed by insert statements that provide explicit values for the identity column, followed by SET IDENTITY_INSERT tablename OFF.

If you are avoiding a column name list, perhaps this 'trick' might help?:

-- Get a comma separated list of a table's column names
',' + COLUMN_NAME AS [text()]
TABLE_NAME = 'TableName'
Order By Ordinal_position
), 1,1, '')

Multipart File upload Spring Boot

@RequestMapping(value="/add/image", method=RequestMethod.POST)
public ResponseEntity upload(@RequestParam("id") Long id, HttpServletResponse response, HttpServletRequest request)
    try {
        MultipartHttpServletRequest multipartRequest=(MultipartHttpServletRequest)request;
        Iterator<String> it=multipartRequest.getFileNames();
        MultipartFile multipart=multipartRequest.getFile(;
        String fileName=id+".png";
        String imageName = fileName;

        byte[] bytes=multipart.getBytes();
        BufferedOutputStream stream= new BufferedOutputStream(new FileOutputStream("src/main/resources/static/image/book/"+fileName));;

        return new ResponseEntity("upload success", HttpStatus.OK);

    } catch (Exception e) {
        return new ResponseEntity("Upload fialed", HttpStatus.BAD_REQUEST);

Angular @ViewChild() error: Expected 2 arguments, but got 1

In Angular 8 , ViewChild takes 2 parameters

 @ViewChild(ChildDirective, {static: false}) Component

High CPU Utilization in java application - why?

You may be victim of a garbage collection problem.

When your application requires memory and it's getting low on what it's configured to use the garbage collector will run often which consume a lot of CPU cycles. If it can't collect anything your memory will stay low so it will be run again and again. When you redeploy your application the memory is cleared and the garbage collection won't happen more than required so the CPU utilization stays low until it's full again.

You should check that there is no possible memory leak in your application and that it's well configured for memory (check the -Xmx parameter, see What does Java option -Xmx stand for?)

Also, what are you using as web framework? JSF relies a lot on sessions and consumes a lot of memory, consider being stateless at most!

Display an image into windows forms

I display images in windows forms when I put it in Load event like this:

    private void Form1_Load( object sender , EventArgs e )
        pictureBox1.ImageLocation = "./image.png"; //path to image
        pictureBox1.SizeMode = PictureBoxSizeMode.AutoSize;

Script to kill all connections to a database (More than RESTRICTED_USER ROLLBACK)

Little known: the GO sql statement can take an integer for the number of times to repeat previous command.

So if you:



GO 2000

This will repeat the USE command 2000 times, force deadlock on all other connections, and take ownership of the single connection. (Giving your query window sole access to do as you wish.)

Changing cell color using apache poi

For apache POI 3.9 you can use the code bellow:

HSSFCellStyle style = workbook.createCellStyle()
style.setFillPattern((short) FillPatternType.SOLID_FOREGROUND.ordinal())

The methods for 3.9 version accept short and you should pay attention to the inputs.

How to shut down the computer from C#

Works starting with windows XP, not available in win 2000 or lower:

This is the quickest way to do it:

Process.Start("shutdown","/s /t 0");

Otherwise use P/Invoke or WMI like others have said.

Edit: how to avoid creating a window

var psi = new ProcessStartInfo("shutdown","/s /t 0");
psi.CreateNoWindow = true;
psi.UseShellExecute = false;

Combating AngularJS executing controller twice

I figured out mine is getting called twice is because i was calling the method twice from my html.

`<form class="form-horizontal" name="x" ng-submit="findX() novalidate >
 <input type="text"....>
 <input type="text"....>
 <input type="text"....>
 <button type="submit" class="btn btn-sm btn-primary" ng-click="findX()"

The highlighted section was causing findX() to be called twice. Hope it helps someone.

How can I control Chromedriver open window size?

C# version of @yonatan-kiron's answer, and Selenium's using statement from their example code.

ChromeOptions chromeOptions = new ChromeOptions();

using (IWebDriver driver = new ChromeDriver(chromeOptions))

WebForms UnobtrusiveValidationMode requires a ScriptResourceMapping for jquery

To fix this problem on specific page need to set some validation settings when page loading. Write code below in Page_Load() method:

protected void Page_Load(object sender, EventArgs e)
        ValidationSettings.UnobtrusiveValidationMode = UnobtrusiveValidationMode.None;

Its work for me in .NET 4.5

Unit test naming best practices

Class Names. For test fixture names, I find that "Test" is quite common in the ubiquitous language of many domains. For example, in an engineering domain: StressTest, and in a cosmetics domain: SkinTest. Sorry to disagree with Kent, but using "Test" in my test fixtures (StressTestTest?) is confusing.

"Unit" is also used a lot in domains. E.g. MeasurementUnit. Is a class called MeasurementUnitTest a test of "Measurement" or "MeasurementUnit"?

Therefore I like to use the "Qa" prefix for all my test classes. E.g. QaSkinTest and QaMeasurementUnit. It is never confused with domain objects, and using a prefix rather than a suffix means that all the test fixtures live together visually (useful if you have fakes or other support classes in your test project)

Namespaces. I work in C# and I keep my test classes in the same namespace as the class they are testing. It is more convenient than having separate test namespaces. Of course, the test classes are in a different project.

Test method names. I like to name my methods WhenXXX_ExpectYYY. It makes the precondition clear, and helps with automated documentation (a la TestDox). This is similar to the advice on the Google testing blog, but with more separation of preconditions and expectations. For example:


Form Submit Execute JavaScript Best Practice?

Attach an event handler to the submit event of the form. Make sure it cancels the default action.

Quirks Mode has a guide to event handlers, but you would probably be better off using a library to simplify the code and iron out the differences between browsers. All the major ones (such as YUI and jQuery) include event handling features, and there is a large collection of tiny event libraries.

Here is how you would do it in YUI 3:

<script src=""></script>
    YUI().use('event', function (Y) {'form').on('submit', function (e) {
            // Whatever else you want to do goes here

Make sure that the server will pick up the slack if the JavaScript fails for any reason.

Printing a char with printf

In C, character constant expressions such as '\n' or 'a' have type int (thus sizeof '\n' == sizeof (int)), whereas in C++ they have type char.

The statement printf("%d", '\0'); should simply print 0; the type of the expression '\0' is int, and its value is 0.

The statement printf("%d", ch); should print the integer encoding for the value in ch (for ASCII, 'a' == 97).

What are the different NameID format used for?

Refer to Section 8.3 of this SAML core pdf of oasis SAML specification.

SP and IdP usually communicate each other about a subject. That subject should be identified through a NAME-IDentifier , which should be in some format so that It is easy for the other party to identify it based on the Format.

All these

1.urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified [default]




are format for the Name Identifiers.

The name format for a transient ID in SAML 1 is urn:mace:shibboleth:1.0:nameIdentifier and in SAML 2 is urn:oasis:names:tc:SAML:2.0:nameid-format:transient

Transient is for [section 8.3.8 of SAML Core]

Indicates that the content of the element is an identifier with transient semantics and SHOULD be treated as an opaque and temporary value by the relying party.

Unspecified can be used and it purely depends on the entities implementation on their own wish.

Is there anything like .NET's NotImplementedException in Java?

No there isn't and it's probably not there, because there are very few valid uses for it. I would think twice before using it. Also, it is indeed easy to create yourself.

Please refer to this discussion about why it's even in .NET.

I guess UnsupportedOperationException comes close, although it doesn't say the operation is just not implemented, but unsupported even. That could imply no valid implementation is possible. Why would the operation be unsupported? Should it even be there? Interface segregation or Liskov substitution issues maybe?

If it's work in progress I'd go for ToBeImplementedException, but I've never caught myself defining a concrete method and then leave it for so long it makes it into production and there would be a need for such an exception.

Blurry text after using CSS transform: scale(); in Chrome

Another fix to try i just found for blurry transforms (translate3d, scaleX) on Chrome is to set the element as "display: inline-table;". It seems to force pixel rounding in some case (on the X axis).

I read subpixel positioning under Chrome was intended and devs won't fix it.

Kafka consumer list


For example

bin/  --list --bootstrap-server localhost:9092

bin/ --describe --group mygroup --bootstrap-server localhost:9092

How to negate 'isblank' function

The solution is isblank(cell)=false

Java 8 NullPointerException in Collectors.toMap

If the value is a String, then this might work: map.entrySet().stream().collect(Collectors.toMap(e -> e.getKey(), e -> Optional.ofNullable(e.getValue()).orElse("")))

C++ JSON Serialization

Does anything, easy like that, exists?? THANKS :))

C++ does not store class member names in compiled code, and there's no way to discover (at runtime) which members (variables/methods) class contains. In other words, you cannot iterate through members of a struct. Because there's no such mechanism, you won't be able to automatically create "JSONserialize" for every object.

You can, however, use any json library to serialize objects, BUT you'll have to write serialization/deserialization code yourself for every class. Either that, or you'll have to create serializeable class similar to QVariantMap that'll be used instead of structs for all serializeable objects.

In other words, if you're okay with using specific type for all serializeable objects (or writing serialization routines yourself for every class), it can be done. However, if you want to automatically serialize every possible class, you should forget about it. If this feature is important to you, try another language.

How to transfer data from JSP to servlet when submitting HTML form

Well, there are plenty of database tutorials online for java (what you're looking for is called JDBC). But if you are using plain servlets, you will have a class that extends HttpServlet and inside it you will have two methods that look like

public void doPost(HttpServletRequest req, HttpServletResponse resp){



public void doGet(HttpServletRequest req, HttpServletResponse resp){


One of them is called to handle GET operations and another is used to handle POST operations. You will then use the HttpServletRequest object to get the parameters that were passed as part of the form like so:

String name = req.getParameter("name");

Then, once you have the data from the form, it's relatively easy to add it to a database using a JDBC tutorial that is widely available on the web. I also suggest searching for a basic Java servlet tutorial to get you started. It's very easy, although there are a number of steps that need to be configured correctly.

convert UIImage to NSData

Try one of the following, depending on your image format:


Returns the data for the specified image in JPEG format.

NSData * UIImageJPEGRepresentation (
   UIImage *image,
   CGFloat compressionQuality


Returns the data for the specified image in PNG format

NSData * UIImagePNGRepresentation (
   UIImage *image

Here the docs.


if you want to access the raw bytes that make up the UIImage, you could use this approach:

CGDataProviderRef provider = CGImageGetDataProvider(image.CGImage);
NSData* data = (id)CFBridgingRelease(CGDataProviderCopyData(provider));
const uint8_t* bytes = [data bytes];

This will give you the low-level representation of the image RGB pixels. (Omit the CFBridgingRelease bit if you are not using ARC).

Difference between res.send and res.json in Express.js

res.json forces the argument to JSON. res.send will take an non-json object or non-json array and send another type. For example:

This will return a JSON number.


This will return a status code and issue a warning to use sendStatus.


If your argument is not a JSON object or array (null,undefined,boolean,string), and you want to ensure it is sent as JSON, use res.json.

javascript node.js next()

It is naming convention used when passing callbacks in situations that require serial execution of actions, e.g. scan directory -> read file data -> do something with data. This is in preference to deeply nesting the callbacks. The first three sections of the following article on Tim Caswell's HowToNode blog give a good overview of this:

Also see the Sequential Actions section of the second part of that posting:

Android: Share plain text using intent (to all messaging apps)

This a great example about share with Intents in Android:

* Share with Intents in Android

//Share text:

Intent intent2 = new Intent(); intent2.setAction(Intent.ACTION_SEND);
intent2.putExtra(Intent.EXTRA_TEXT, "Your text here" );  
startActivity(Intent.createChooser(intent2, "Share via"));

//via Email:

Intent intent2 = new Intent();
intent2.putExtra(Intent.EXTRA_EMAIL, new String[]{EMAIL1, EMAIL2});
intent2.putExtra(Intent.EXTRA_SUBJECT, "Email Subject");
intent2.putExtra(Intent.EXTRA_TEXT, "Your text here" );  

//Share Files:


boolean isPNG = (path.toLowerCase().endsWith(".png")) ? true : false;

Intent i = new Intent(Intent.ACTION_SEND);
//Set type of file
    i.setType("image/png");//With png image file or set "image/*" type

Uri imgUri = Uri.fromFile(new File(path));//Absolute Path of image
i.putExtra(Intent.EXTRA_STREAM, imgUri);//Uri of image
startActivity(Intent.createChooser(i, "Share via"));


File f = new File(path1);

   Intent intent2 = new Intent();
   intent2.setType("application/");//APk file type  
   intent2.putExtra(Intent.EXTRA_STREAM, Uri.fromFile(f) );  
   startActivity(Intent.createChooser(intent2, "Share via"));

How to write multiple conditions in with "else if"

ifeq ($(CHIPSET),8960)
else ifeq ($(CHIPSET),8930)
else ifeq ($(CHIPSET),8064)
else ifeq ($(CHIPSET), 9x15)

How to declare a variable in MySQL?


SET @var_name = value 


SET @var := value

both operators = and := are accepted


SELECT col1, @var_name := col2 from tb_name WHERE "conditon";

if multiple record sets found only the last value in col2 is keep (override);

SELECT col1, col2 INTO @var_name, col3 FROM .....

in this case the result of select is not containing col2 values

Ex both methods used

-- TRIGGER_BEFORE_INSERT --- setting a column value from calculations

SELECT count(*) INTO @NR FROM a_table WHERE a_condition;
SET NEW.ord_col =  IFNULL( @NR, 0 ) + 1;

What does -z mean in Bash?


string is null, that is, has zero length

String=''   # Zero-length ("null") string variable.

if [ -z "$String" ]
  echo "\$String is null."
  echo "\$String is NOT null."
fi     # $String is null.

How to remove all the punctuation in a string? (Python)

import string

asking = "".join(l for l in asking if l not in string.punctuation)

filter with string.punctuation.

How to run a subprocess with Python, wait for it to exit and get the full stdout as a string?

I am using the following construct, although you might want to avoid shell=True. This gives you the output and error message for any command, and the error code as well:

process = subprocess.Popen(cmd, shell=True,

# wait for the process to terminate
out, err = process.communicate()
errcode = process.returncode

Get class list for element with jQuery

A bit late, but using the extend() function lets you call "hasClass()" on any element, e.g.:
var hasClass = $('#divId').hasClass('someClass');

(function($) {
    hasClass: new function(className) {
        var classAttr = $J(this).attr('class');
        if (classAttr != null && classAttr != undefined) {
            var classList = classAttr.split(/\s+/);
            for(var ix = 0, len = classList.length;ix < len;ix++) {
                if (className === classList[ix]) {
                    return true;
        return false;
}); })(jQuery);

How can I debug git/git-shell related problems?

If its over SSH, you can use the following:

For a higher debug level for type -vv or -vvv for debug level 2 and 3 respectively:

# Debug level 1
GIT_SSH_COMMAND="ssh -v" git clone <repositoryurl>

# Debug level 2
GIT_SSH_COMMAND="ssh -vv" git clone <repositoryurl>

# Debug level 3
GIT_SSH_COMMAND="ssh -vvv" git clone <repositoryurl>

This is mainly useful to handle public and private key problems with the server. You can use this command for any git command, not only 'git clone'.

Is there a performance difference between CTE , Sub-Query, Temporary Table or Table Variable?

There is no rule. I find CTEs more readable, and use them unless they exhibit some performance problem, in which case I investigate the actual problem rather than guess that the CTE is the problem and try to re-write it using a different approach. There is usually more to the issue than the way I chose to declaratively state my intentions with the query.

There are certainly cases when you can unravel CTEs or remove subqueries and replace them with a #temp table and reduce duration. This can be due to various things, such as stale stats, the inability to even get accurate stats (e.g. joining to a table-valued function), parallelism, or even the inability to generate an optimal plan because of the complexity of the query (in which case breaking it up may give the optimizer a fighting chance). But there are also cases where the I/O involved with creating a #temp table can outweigh the other performance aspects that may make a particular plan shape using a CTE less attractive.

Quite honestly, there are way too many variables to provide a "correct" answer to your question. There is no predictable way to know when a query may tip in favor of one approach or another - just know that, in theory, the same semantics for a CTE or a single subquery should execute the exact same. I think your question would be more valuable if you present some cases where this is not true - it may be that you have discovered a limitation in the optimizer (or discovered a known one), or it may be that your queries are not semantically equivalent or that one contains an element that thwarts optimization.

So I would suggest writing the query in a way that seems most natural to you, and only deviate when you discover an actual performance problem the optimizer is having. Personally I rank them CTE, then subquery, with #temp table being a last resort.

How to properly apply a lambda function into a pandas data frame column

You need to add else in your lambda function. Because you are telling what to do in case your condition(here x < 90) is met, but you are not telling what to do in case the condition is not met.

sample['PR'] = sample['PR'].apply(lambda x: 'NaN' if x < 90 else x) 

Angular - ui-router get previous state

For sake of readability, I'll place my solution (based of stu.salsbury's anwser) here.

Add this code to your app's abstract template so it runs on every page.

$rootScope.$on('$stateChangeSuccess', function(ev, to, toParams, from, fromParams) {
    $rootScope.previousState =;
    $rootScope.currentState =;
    console.log('Previous state:'+$rootScope.previousState)
    console.log('Current state:'+$rootScope.currentState)

Keeps track of the changes in rootScope. Its pretty handy.

Android XML Percent Symbol

A tricky method: using small percent sign as below

 <string name="zone_50">Fat Burning (50&#65130; to 60&#65130;)</string> 

Percent Sign on Wikipedia

"Multiple definition", "first defined here" errors

I had a similar issue when not using inline for my global function that was included in two places.

How to assert greater than using JUnit Assert?

You can put it like this

  assertTrue("your fail message ",Long.parseLong(previousTokenValues[1]) > Long.parseLong(currentTokenValues[1]));

Django TemplateDoesNotExist?

I had an embarrassing problem...

I got this error because I was rushing and forgot to put the app in INSTALLED_APPS. You would think Django would raise a more descriptive error.

How to create an exit message

If you want to denote an actual error in your code, you could raise a RuntimeError exception:

raise RuntimeError, 'Message goes here'

This will print a stacktrace, the type of the exception being raised and the message that you provided. Depending on your users, a stacktrace might be too scary, and the actual message might get lost in the noise. On the other hand, if you die because of an actual error, a stacktrace will give you additional information for debugging.

Python Brute Force algorithm

If you REALLY want to brute force it, try this, but it will take you a ridiculous amount of time:

your_list = 'abcdefghijklmnopqrstuvwxyz'
complete_list = []
for current in xrange(10):
    a = [i for i in your_list]
    for y in xrange(current):
        a = [x+i for i in your_list for x in a]
    complete_list = complete_list+a

On a smaller example, where list = 'ab' and we only go up to 5, this prints the following:

['a', 'b', 'aa', 'ba', 'ab', 'bb', 'aaa', 'baa', 'aba', 'bba', 'aab', 'bab', 'abb', 'bbb', 'aaaa', 'baaa', 'abaa', 'bbaa', 'aaba', 'baba', 'abba', 'bbba', 'aaab', 'baab', 'abab', 'bbab', 'aabb', 'babb', 'abbb', 'bbbb', 'aaaaa', 'baaaa', 'abaaa', 'bbaaa', 'aabaa', 'babaa', 'abbaa', 'bbbaa', 'aaaba','baaba', 'ababa', 'bbaba', 'aabba', 'babba', 'abbba', 'bbbba', 'aaaab', 'baaab', 'abaab', 'bbaab', 'aabab', 'babab', 'abbab', 'bbbab', 'aaabb', 'baabb', 'ababb', 'bbabb', 'aabbb', 'babbb', 'abbbb', 'bbbbb']

How to change color of Toolbar back button in Android?

Simple and no Worries

 <?xml version="1.0" encoding="utf-8"?>
    < xmlns:android=""


                app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />


        <include layout="@layout/testing" />


How do I serialize an object and save it to a file in Android?

I just made a class to handle this with Generics, so it can be used with all the object types that are serializable:

public class SerializableManager {

     * Saves a serializable object.
     * @param context The application context.
     * @param objectToSave The object to save.
     * @param fileName The name of the file.
     * @param <T> The type of the object.

    public static <T extends Serializable> void saveSerializable(Context context, T objectToSave, String fileName) {
        try {
            FileOutputStream fileOutputStream = context.openFileOutput(fileName, Context.MODE_PRIVATE);
            ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream);


        } catch (IOException e) {

     * Loads a serializable object.
     * @param context The application context.
     * @param fileName The filename.
     * @param <T> The object type.
     * @return the serializable object.

    public static<T extends Serializable> T readSerializable(Context context, String fileName) {
        T objectToReturn = null;

        try {
            FileInputStream fileInputStream = context.openFileInput(fileName);
            ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);
            objectToReturn = (T) objectInputStream.readObject();

        } catch (IOException | ClassNotFoundException e) {

        return objectToReturn;

     * Removes a specified file.
     * @param context The application context.
     * @param filename The name of the file.

    public static void removeSerializable(Context context, String filename) {


What are .dex files in Android?

dex file is a file that is executed on the Dalvik VM.

Dalvik VM includes several features for performance optimization, verification, and monitoring, one of which is Dalvik Executable (DEX).

Java source code is compiled by the Java compiler into .class files. Then the dx (dexer) tool, part of the Android SDK processes the .class files into a file format called DEX that contains Dalvik byte code. The dx tool eliminates all the redundant information that is present in the classes. In DEX all the classes of the application are packed into one file. The following table provides comparison between code sizes for JVM jar files and the files processed by the dex tool.

The table compares code sizes for system libraries, web browser applications, and a general purpose application (alarm clock app). In all cases dex tool reduced size of the code by more than 50%.

enter image description here

In standard Java environments each class in Java code results in one .class file. That means, if the Java source code file has one public class and two anonymous classes, let’s say for event handling, then the java compiler will create total three .class files.

The compilation step is same on the Android platform, thus resulting in multiple .class files. But after .class files are generated, the “dx” tool is used to convert all .class files into a single .dex, or Dalvik Executable, file. It is the .dex file that is executed on the Dalvik VM. The .dex file has been optimized for memory usage and the design is primarily driven by sharing of data.

How to do a SOAP Web Service call from Java class?

Or just use Apache CXF's wsdl2java to generate objects you can use.

It is included in the binary package you can download from their website. You can simply run a command like this:

$ ./wsdl2java -p com.mynamespace.for.the.api.objects -autoNameResolution

It uses the wsdl to generate objects, which you can use like this (object names are also grabbed from the wsdl, so yours will be different a little):

DefaultWebService defaultWebService = new DefaultWebService();
String res = defaultWebService.getDefaultWebServiceHttpSoap11Endpoint().login("webservice","dadsadasdasd");

There is even a Maven plug-in which generates the sources:

Note: If you generate sources using CXF and IDEA, you might want to look at this:

How to bind 'touchstart' and 'click' events but not respond to both?

Taking advantage of the fact that a click will always follow a touch event, here is what I did to get rid of the "ghost click" without having to use timeouts or global flags.

$('#buttonId').on('touchstart click', function(event){
    if ($(this).data("already")) {
        $(this).data("already", false);
        return false;
    } else if (event.type == "touchstart") {
        $(this).data("already", true);
    //your code here

Basically whenever an ontouchstart event fires on the element, a flag a set and then subsequently removed (and ignored), when the click comes.

Equivalent of typedef in C#

You can use an open source library and NuGet package called LikeType that I created that will give you the GenericClass<int> behavior that you're looking for.

The code would look like:

public class SomeInt : LikeType<int>
    public SomeInt(int value) : base(value) { }

public class HashSetExample
    public void Contains_WhenInstanceAdded_ReturnsTrueWhenTestedWithDifferentInstanceHavingSameValue()
        var myInt = new SomeInt(42);
        var myIntCopy = new SomeInt(42);
        var otherInt = new SomeInt(4111);

        Assert.IsTrue(myInt == myIntCopy);

        var mySet = new HashSet<SomeInt>();


Iterating over a 2 dimensional python list

>>> mylist = [["%s,%s"%(i,j) for j in range(columns)] for i in range(rows)]
>>> mylist
[['0,0', '0,1', '0,2'], ['1,0', '1,1', '1,2'], ['2,0', '2,1', '2,2']]
>>> zip(*mylist)
[('0,0', '1,0', '2,0'), ('0,1', '1,1', '2,1'), ('0,2', '1,2', '2,2')]
>>> sum(zip(*mylist),())
('0,0', '1,0', '2,0', '0,1', '1,1', '2,1', '0,2', '1,2', '2,2')

Generating Request/Response XML from a WSDL

The easiest way is to use this chrome extension link, happy web service requesting

How to get a complete list of object's methods and attributes?

Only to supplement:

  1. dir() is the most powerful/fundamental tool. (Most recommended)
  2. Solutions other than dir() merely provide their way of dealing the output of dir().

    Listing 2nd level attributes or not, it is important to do the sifting by yourself, because sometimes you may want to sift out internal vars with leading underscores __, but sometimes you may well need the __doc__ doc-string.

  3. __dir__() and dir() returns identical content.
  4. __dict__ and dir() are different. __dict__ returns incomplete content.
  5. IMPORTANT: __dir__() can be sometimes overwritten with a function, value or type, by the author for whatever purpose.

    Here is an example:

    \\...\\ in traverse(self, mod, search_attributes)
    445             if prefix in traversed_mod_names:
    446                 continue
    447             names = dir(m)
    448             for name in names:
    449                 obj = getattr(m,name)

    TypeError: descriptor __dir__ of 'object' object needs an argument

    The author of PyTorch modified the __dir__() method to something that requires an argument. This modification makes dir() fail.

  6. If you want a reliable scheme to traverse all attributes of an object, do remember that every pythonic standard can be overridden and may not hold, and every convention may be unreliable.

How to import a single table in to mysql database using command line

Command Line

Import / Export for single table:

Exporting table schema

 -> mysqldump -u your_user_name -p your_database_name table_name > test.sql

This will create a file named test.sql and creates table sql command to create table table_name.

Importing data into table

 -> mysql -u your_user_name -p database_name table_name < test.sql

Make sure your test.sql file is in the same directory, if not navigate through the path and then run the command.

onChange and onSelect in DropDownList

Simply & Easy : JavaScript code :

function JoinedOrNot(){
    var cat = document.getElementById("mySelect");
    if(cat.value == "yes"){
        document.getElementById("mySelect1").disabled = false;
        document.getElementById("mySelect1").disabled = true;

just add in this line [onChange="JoinedOrNot()"] : <select id="mySelect" onchange="JoinedOrNot()">

it's work fine ;)

powerpoint loop a series of animation

Unfortunately you're probably done with the animation and presentation already. In the hopes this answer can help future questioners, however, this blog post has a walkthrough of steps that can loop a single slide as a sort of sub-presentation.

First, click Slide Show > Set Up Show.

Put a checkmark to Loop continuously until 'Esc'.

Click Ok. Now, Click Slide Show > Custom Shows. Click New.

Select the slide you are looping, click Add. Click Ok and Close.

Click on the slide you are looping. Click Slide Show > Slide Transition. Under Advance slide, put a checkmark to Automatically After. This will allow the slide to loop automatically. Do NOT Apply to all slides.

Right click on the thumbnail of the current slide, select Hide Slide.

Now, you will need to insert a new slide just before the slide you are looping. On the new slide, insert an action button. Set the hyperlink to the custom show you have created. Put a checkmark on "Show and Return"

This has worked for me.