Programs & Examples On #Setwindowlong

How can I issue a single command from the command line through sql plus?

@find /v "@" < %0 | sqlplus -s scott/tiger@orcl & goto :eof

select sysdate from dual;

Easiest way to convert a List to a Set in Java

Let's not forget our relatively new friend, stream API. If you need to preprocess list before converting it to a set, it's better to have something like:<here goes some preprocessing>.collect(Collectors.toSet());

C++ - How to append a char to char*?

Remove those char * ret declarations inside if blocks which hide outer ret. Therefor you have memory leak and on the other hand un-allocated memory for ret.

To compare a c-style string you should use strcmp(array,"") not array!="". Your final code should looks like below:

char* appendCharToCharArray(char* array, char a)
    size_t len = strlen(array);

    char* ret = new char[len+2];

    strcpy(ret, array);    
    ret[len] = a;
    ret[len+1] = '\0';

    return ret;

Note that, you must handle the allocated memory of returned ret somewhere by delete[] it.


Why you don't use std::string? it has .append method to append a character at the end of a string:

std::string str;

// or
str += x;

How to round the corners of a button

I tried the following solution with the UITextArea and I expect this will work with UIButton as well.

First of all import this in your .m file -

#import <QuartzCore/QuartzCore.h>

and then in your loadView method add following lines

    yourButton.layer.cornerRadius = 10; // this value vary as per your desire
    yourButton.clipsToBounds = YES;

How can I fill a div with an image while keeping it proportional?

Here you have my working example. I have used a trick that is setting the image as background of the div container with background-size:cover and background-position:center center

I have placed the image with width:100% and opacity:0 making it invisible. Note that I am showing my image only because I have an special interest on calling the child click event.

Please note that altought I am ussing angular it is completely irrelevant.

<div class="foto-item" ng-style="{'background-image':'url('+foto.path+')'}">
    <img class="materialboxed" ng-class="foto.picid" ng-src="{{foto.path}}" style="opacity: 0;filter: alpha(opacity=0);" width="100%" onclick="$('.materialboxed')/>
.foto-item {
height: 75% !important;
width: 100%;
position: absolute;
top: 0;
left: 0;
background-size: cover;
background-position: center center;

The result is the one that you define as optimal in all cases

Implement touch using Python?

This answer is compatible with all versions since Python-2.5 when keyword with has been released.

1. Create file if does not exist + Set current time
(exactly same as command touch)

import os

fname = 'directory/filename.txt'
with open(fname, 'a'):     # Create file if does not exist
    os.utime(fname, None)  # Set access/modified times to now
                           # May raise OSError if file does not exist

A more robust version:

import os

with open(fname, 'a'):
  try:                     # Whatever if file was already existing
    os.utime(fname, None)  # => Set current time anyway
  except OSError:
    pass  # File deleted between open() and os.utime() calls

2. Just create the file if does not exist
(does not update time)

with open(fname, 'a'):  # Create file if does not exist

3. Just update file access/modified times
(does not create file if not existing)

import os

    os.utime(fname, None)  # Set access/modified times to now
except OSError:
    pass  # File does not exist (or no permission)

Using os.path.exists() does not simplify the code:

from __future__ import (absolute_import, division, print_function)
import os

if os.path.exists(fname):
    os.utime(fname, None)  # Set access/modified times to now
  except OSError:
    pass  # File deleted between exists() and utime() calls
          # (or no permission)

Bonus: Update time of all files in a directory

from __future__ import (absolute_import, division, print_function)
import os

number_of_files = 0

#   Current directory which is "walked through"
#   |     Directories in root
#   |     |  Files in root       Working directory
#   |     |  |                     |
for root, _, filenames in os.walk('.'):
  for fname in filenames:
    pathname = os.path.join(root, fname)
      os.utime(pathname, None)  # Set access/modified times to now
      number_of_files += 1
    except OSError as why:
      print('Cannot change time of %r because %r', pathname, why)

print('Changed time of %i files', number_of_files)

Android: why setVisibility(View.GONE); or setVisibility(View.INVISIBLE); do not work

You can think it as a CSS style visibility & display.

<div style="visibility:visible; display:block">
    This is View.VISIBLE : Content is displayed normally.

<div style="visibility:hidden; display:block">
    This is View.INVISIBLE : Content is not displayed, but div still takes up place, but empty.

<div style="display:none">
    This is View.GONE : Container div is not shown, you can say the content is not displayed.

Binding ItemsSource of a ComboBoxColumn in WPF DataGrid

The correct solution seems to be:

    <CollectionViewSource x:Key="ItemsCVS" Source="{Binding MyItems}" />
<!-- ... -->
<DataGrid ItemsSource="{Binding MyRecords}">
    <DataGridComboBoxColumn Header="Column With Predefined Values"
                            ItemsSource="{Binding Source={StaticResource ItemsCVS}}"
                            SelectedValueBinding="{Binding MyItemId}"
                            DisplayMemberPath="StatusCode" />

The layout above works perfectly fine for me, and should work for others. This design choice also makes sense, though it isn't very well explained anywhere. But if you have a data column with predefined values, those values typically don't change during run-time. So creating a CollectionViewSource and initializing the data once makes sense. It also gets rid of the longer bindings to find an ancestor and bind on it's data context (which always felt wrong to me).

I am leaving this here for anyone else who struggled with this binding, and wondered if there was a better way (As this page is obviously still coming up in search results, that's how I got here).

How to display length of filtered ng-repeat data

Since AngularJS 1.3 you can use aliases:

item in items | filter:x as results

and somewhere:

<span>Total {{results.length}} result(s).</span>

From docs:

You can also provide an optional alias expression which will then store the intermediate results of the repeater after the filters have been applied. Typically this is used to render a special message when a filter is active on the repeater, but the filtered result set is empty.

For example: item in items | filter:x as results will store the fragment of the repeated items as results, but only after the items have been processed through the filter.

Git copy file preserving history

This process preserve history, but is little workarround:

# make branchs to new files
$: git mv arquivos && git commit

# in original branch, remove original files
$: git rm arquivos && git commit

# do merge and fix conflicts
$: git merge branch-copia-arquivos

# back to original branch and revert commit removing files
$: git revert commit

Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2

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

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

Replace below line of code :

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


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

Hide axis and gridlines Highcharts

If you doesn't want to touch the config object, you just hide the grid by css:

.chart-container .highcharts-grid {
   display: none;

How to check if a DateTime field is not null or empty?

DateTime is not standard nullable type. If you want assign null to DateTime type of variable, you have to use DateTime? type which supports null value.

If you only want test your variable to be set (e.g. variable holds other than default value), you can use keyword "default" like in following code:

if (dateTimeVariable == default(DateTime))
    //do work for dateTimeVariable == null situation

Adb over wireless without usb cable at all for not rooted phones

For your question

Adb over wireless without USB cable at all for not rooted phones

 You can't do it for now without USB cable.

But you have an option:

Note: You need put USB at least once to achieve the following:

You need to connect your device to your computer via USB cable. Make sure USB debugging is working. You can check if it shows up when running adb devices.

Open cmd in ...\AppData\Local\Android\sdk\platform-tools

Step1: Run adb devices

Ex: C:\pathToSDK\platform-tools>adb devices

You can check if it shows up when running adb devices.

Step2: Run adb tcpip 5555

Ex: C:\pathToSDK\platform-tools>adb tcpip 5555

Disconnect your device (remove the USB cable).

Step3: Go to the Settings -> About phone -> Status to view the IP address of your phone.


Step4: Run `adb connect

Ex: C:\pathToSDK\platform-tools>adb connect

Step5: Run adb devices again, you should see your device.

Now you can execute adb commands or use your favourite IDE for android development - wireless!

Now you might ask, what do I have to do when I move into a different work space and change WiFi networks? You do not have to repeat steps 1 to 3 (these set your phone into WiFi-debug mode). You do have to connect to your phone again by executing steps 4 to 6.

Unfortunately, the android phones lose the WiFi-debug mode when restarting. Thus, if your battery died, you have to start over. Otherwise, if you keep an eye on your battery and do not restart your phone, you can live without a cable for weeks!

See here for more

Happy wireless coding!



If you set C:\pathToSDK\platform-tools this path in Environment variables then there is no need to repeat all steps, you can simply use only Step 4 that's it, it will connect to your device.

To set path : My Computer-> Right click--> properties -> Advanced system settings -> Environment variables -> edit path in System variables -> paste the platform-tools path in variable value -> ok -> ok -> ok

Loop code for each file in a directory

Looks for the function glob():

$files = glob("dir/*.jpg");
foreach($files as $jpg){
    echo $jpg, "\n";

jQuery callback on image load (even when the image is cached)

A solution I found (This code taken directly from the comment)

var photo = document.getElementById('image_id');
var img = new Image();
img.addEventListener('load', myFunction, false);
img.src = 'http://newimgsource.jpg';
photo.src = img.src;

C++ correct way to return pointer to array from function

New answer to new question:

You cannot return pointer to automatic variable (int c[5]) from the function. Automatic variable ends its lifetime with return enclosing block (function in this case) - so you are returning pointer to not existing array.

Either make your variable dynamic:

int* test (int a[5], int b[5]) {
    int* c = new int[5];
    for (int i = 0; i < 5; i++) c[i] = a[i]+b[i];
    return c;

Or change your implementation to use std::array:

std::array<int,5> test (const std::array<int,5>& a, const std::array<int,5>& b) 
   std::array<int,5> c;
   for (int i = 0; i < 5; i++) c[i] = a[i]+b[i];
   return c;

In case your compiler does not provide std::array you can replace it with simple struct containing an array:

struct array_int_5 { 
   int data[5];
   int& operator [](int i) { return data[i]; } 
   int operator const [](int i) { return data[i]; } 

Old answer to old question:

Your code is correct, and ... hmm, well, ... useless. Since arrays can be assigned to pointers without extra function (note that you are already using this in your function):

int arr[5] = {1, 2, 3, 4, 5};
//int* pArr = test(arr);
int* pArr = arr;

Morever signature of your function:

int* test (int in[5])

Is equivalent to:

int* test (int* in)

So you see it makes no sense.

However this signature takes an array, not pointer:

int* test (int (&in)[5])

How to create bitmap from byte array?

In addition, you can simply convert byte array to Bitmap.

var bmp = new Bitmap(new MemoryStream(imgByte));

You can also get Bitmap from file Path directly.

Bitmap bmp = new Bitmap(Image.FromFile(filePath));

How do you append to a file?

The 'a' parameter signifies append mode. If you don't want to use with open each time, you can easily write a function to do it for you:

def append(txt='\nFunction Successfully Executed', file):
    with open(file, 'a') as f:

If you want to write somewhere else other than the end, you can use 'r+':

import os

with open(file, 'r+') as f:, os.SEEK_END)
    f.write("text to add")

Finally, the 'w+' parameter grants even more freedom. Specifically, it allows you to create the file if it doesn't exist, as well as empty the contents of a file that currently exists.

Credit for this function goes to @Primusa

How can I split a shell command over multiple lines when using an IF statement?

For Windows/WSL/Cygwin etc users:

Make sure that your line endings are standard Unix line feeds, i.e. \n (LF) only.

Using Windows line endings \r\n (CRLF) line endings will break the command line break.

This is because having \ at the end of a line with Windows line ending translates to \ \r \n.
As Mark correctly explains above:

The line-continuation will fail if you have whitespace after the backslash and before the newline.

This includes not just space () or tabs (\t) but also the carriage return (\r).

Bundler: Command not found

You can also create a symlink:

ln -s /opt/ruby-enterprise-1.8.7-2010.02/lib/ruby/gems/1.8/gems/bin/bundle /usr/bin/bundle

How to open my files in data_folder with pandas using relative path?

current_file = os.path.abspath(os.path.dirname(__file__)) #older/folder2/scripts_folder

csv_filename = os.path.join(current_file, '../data_folder/data.csv')

What is %timeit in python?

IPython intercepts those, they're called built-in magic commands, here's the list:

You can also create your own custom magics,

Your timeit is here

How to get the path of a running JAR file?

String path = getClass().getResource("").getPath();

The path always refers to the resource within the jar file.

Converting two lists into a matrix

Assuming lengths of portfolio and index are the same:

matrix = []
for i in range(len(portfolio)):
    matrix.append([portfolio[i], index[i]])

Or a one-liner using list comprehension:

matrix2 = [[portfolio[i], index[i]] for i in range(len(portfolio))]

How to create large PDF files (10MB, 50MB, 100MB, 200MB, 500MB, 1GB, etc.) for testing purposes?

Partly it depends on what you are trying to increase the size of... number of pages, number of images, size of a single image. In my experience, the vast bulk (90%+) of any given 'large' PDF file will be the images.

You could try using a pro product like Adobe InDesign to quickly build a large project and export it as a PDF.

Adobe Acrobat Pro has built-in tools to optimize PDF files -- you try using the tools to 'un-optimize' your file. :)

Expression ___ has changed after it was checked

I switched from AfterViewInit to AfterContentChecked and It worked for me.

Here is the process

  1. Add dependency in your constructor:

    constructor (private cdr: ChangeDetectorRef) {}

  2. and call your login in implemented method code here:

     ngAfterContentChecked() {
      // call or add here your code

add item in array list of android

you can use this add string to list on a button click

final String a[]={"hello","world"};
final ArrayAdapter<String> at=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1,a);
final ListView sp=(ListView)findViewById(;
final EditText et=(EditText)findViewById(;
Button b=(Button)findViewById(;
b.setOnClickListener(new OnClickListener() 

            public void onClick(View v) 
                // TODO Auto-generated method stub
                int k=sp.getCount();
                String a1[]=new String[k+1];
                for(int i=0;i<k;i++)
                ArrayAdapter<String> ats=new ArrayAdapter<String>(getApplicationContext(), android.R.layout.simple_list_item_1,a1);

So on a button click it will get string from edittext and store in listitem. you can change this to your needs.

What is the best way to access redux store outside a react component?

It might be a bit late but i think the best way is to use axios.interceptors as below. Import urls might change based on your project setup.


import axios from 'axios';
import setupAxios from './redux/setupAxios';
import store from './redux/store';

// some other codes

setupAxios(axios, store);


export default function setupAxios(axios, store) {
        (config) => {
            const {
                auth: { tokens: { authorization_token } },
            } = store.getState();

            if (authorization_token) {
                config.headers.Authorization = `Bearer ${authorization_token}`;

            return config;
       (err) => Promise.reject(err)

update columns values with column of another table based on condition

Something like this should do it :

UPDATE table1 
   SET table1.Price = table2.price 
   FROM table1  INNER JOIN  table2 ON =

You can also try this:

UPDATE table1 
   SET price=(SELECT price FROM table2 WHERE;

Eclipse - "Workspace in use or cannot be created, chose a different one."

An additional reason could be that you're pointing to a workspace on a drive that no longer exists, thinking that you're choosing the valid one. For instance, for me the workspace used to exist on the F drive, but now it is on my D drive. Even though I don't have the F drive anymore it is still listed as a workspace I once used during Eclipse startup. When I choose this old workspace Eclipse complains that the workspace is "in use", which is very strange.

How to convert a Collection to List?

What you request is quite a costy operation, make sure you don't need to do it often (e.g in a cycle).

If you need it to stay sorted and you update it frequently, you can create a custom collection. For example, I came up with one that has your TreeBidiMap and TreeMultiset under the hood. Implement only what you need and care about data integrity.

class MyCustomCollection implements Map<K, V> {
    TreeBidiMap<K, V> map;
    TreeMultiset<V> multiset;
    public V put(K key, V value) {
        removeValue(map.put(key, value));
    public boolean remove(K key) {
    /** removes value that was removed/replaced in map */
    private removeValue(V value) {
        if (value != null) {
    public Set<K> keySet() {
        return Collections.unmodifiableSet(map.keySet());
    public Collection<V> values() {
        return Collections.unmodifiableCollection(multiset);
    // many more methods to be implemented, e.g. count, isEmpty etc.
    // but these are fairly simple

This way, you have a sorted Multiset returned from values(). However, if you need it to be a list (e.g. you need the array-like get(index) method), you'd need something more complex.

For brevity, I only return unmodifiable collections. What @Lino mentioned is correct, and modifying the keySet or values collection as it is would make it inconsistent. I don't know any consistent way to make the values mutable, but the keySet could support remove if it uses the remove method from the MyCustomCollection class above.

How to fix an UnsatisfiedLinkError (Can't find dependent libraries) in a JNI project

I'm pretty sure the classpath and the shared library search path have little to do with each other. According to The JNI Book (which admittedly is old), on Windows if you do not use the java.library.path system property, the DLL needs to be in the current working directory or in a directory listed in the Windows PATH environment variable.


Looks like Oracle has removed the PDF from its website. I've updated the link above to point to an instance of the PDF living at University of Texas - Arlington.

Also, you can also read Oracle's HTML version of the JNI Specification. That lives in the Java 8 section of the Java website and so hopefully will be around for a while.

Update 2:

At least in Java 8 (I haven't checked earlier versions) you can do:

java -XshowSettings:properties -version

to find the shared library search path. Look for the value of the java.library.path property in that output.

Get the second highest value in a MySQL table

Found another interesting solution

SELECT salary 
FROM emp 
WHERE salary = (SELECT DISTINCT(salary) 
                FROM emp as e1 
                WHERE (n) = (SELECT COUNT(DISTINCT(salary)) 
                             FROM emp as e2 
                             WHERE e1.salary <= e2.salary))

Sorry. Forgot to write. n is the nth number of salary which you want.

How to reduce the image size without losing quality in PHP

well I think I have something interesting for you... I wrote it for the exact same purpose. Highly customizable, and does it in a great way.

How to make an android app to always run in background?

You have to start a service in your Application class to run it always. If you do that, your service will be always running. Even though user terminates your app from task manager or force stop your app, it will start running again.

Create a service:

public class YourService extends Service {

    public IBinder onBind(Intent intent) {
        return null;

    public int onStartCommand(Intent intent, int flags, int startId) {
        // do your jobs here
        return super.onStartCommand(intent, flags, startId);

Create an Application class and start your service:

public class App extends Application {

    public void onCreate() {

        startService(new Intent(this, YourService.class));

Add "name" attribute into the "application" tag of your AndroidManifest.xml


Also, don't forget to add your service in the "application" tag of your AndroidManifest.xml

<service android:name=".YourService"/>

And also this permission request in the "manifest" tag (if API level 28 or higher):

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


After Android Oreo, Google introduced some background limitations. Therefore, this solution above won't work probably. When a user kills your app from task manager, Android System will kill your service as well. If you want to run a service which is always alive in the background. You have to run a foreground service with showing an ongoing notification. So, edit your service like below.

public class YourService extends Service {

    private static final int NOTIF_ID = 1;
    private static final String NOTIF_CHANNEL_ID = "Channel_Id";

    public IBinder onBind(Intent intent) {
        return null;

    public int onStartCommand(Intent intent, int flags, int startId){

        // do your jobs here

        return super.onStartCommand(intent, flags, startId);

    private void startForeground() {
        Intent notificationIntent = new Intent(this, MainActivity.class);

        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0,
                notificationIntent, 0);

        startForeground(NOTIF_ID, new NotificationCompat.Builder(this, 
                NOTIF_CHANNEL_ID) // don't forget create a notification channel first
                .setContentText("Service is running background")


Unfortunately, some OEMs (Xiaomi, OnePlus, Samsung, Huawei etc.) restrict background operations due to provide longer battery life. There is no proper solution for these OEMs. Users need to allow some special permissions that are specific for OEMs or they need to add your app into whitelisted app list by device settings. You can find more detail information from

If background operations are an obligation for you, you need to explain it to your users why your feature is not working and how they can enable your feature by allowing those permissions. I suggest you to use AutoStarter library ( in order to redirect your users regarding permissions page easily from your app.

By the way, if you need to run some periodic work instead of having continuous background job. You better take a look WorkManager (

How to convert JSONObjects to JSONArray?

To deserialize the response need to use HashMap:

String resp = ...//String output from your source

Gson gson = new GsonBuilder().create();

class TheResponse{
 HashMap<String,Song> songs;

class Song{
  String id;
  String pos;

Check if specific input file is empty

You can check if there is a value, and if the image is valid by doing the following:

if(empty($_FILES['cover_image']['tmp_name']) || !is_uploaded_file($_FILES['cover_image']['tmp_name']))
   // Handle no image here...

How to top, left justify text in a <td> cell that spans multiple rows

 <td rowspan="2" style="text-align:left;vertical-align:top;padding:0">Save a lot</td>

That should do it.

Go to first line in a file in vim?

In command mode (press Esc if you are not sure) you can use:

  • gg,
  • :1,
  • 1G,
  • or 1gg.

Does VBScript have a substring() function?

Yes, Mid.

Dim sub_str
sub_str = Mid(source_str, 10, 5)

The first parameter is the source string, the second is the start index, and the third is the length.

@bobobobo: Note that VBScript strings are 1-based, not 0-based. Passing 0 as an argument to Mid results in "invalid procedure call or argument Mid".

Hibernate error - QuerySyntaxException: users is not mapped [from users]

For example: your bean class name is UserDetails

Query query = entityManager. createQuery("Select UserName from **UserDetails** "); 

You do not give your table name on the Db. you give the class name of bean.

How to blur background images in Android

This is an easy way to blur Images Efficiently with Android's RenderScript that I found on this article

  1. Create a Class called BlurBuilder

    public class BlurBuilder {
      private static final float BITMAP_SCALE = 0.4f;
      private static final float BLUR_RADIUS = 7.5f;
      public static Bitmap blur(Context context, Bitmap image) {
        int width = Math.round(image.getWidth() * BITMAP_SCALE);
        int height = Math.round(image.getHeight() * BITMAP_SCALE);
        Bitmap inputBitmap = Bitmap.createScaledBitmap(image, width, height, false);
        Bitmap outputBitmap = Bitmap.createBitmap(inputBitmap);
        RenderScript rs = RenderScript.create(context);
        ScriptIntrinsicBlur theIntrinsic = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
        Allocation tmpIn = Allocation.createFromBitmap(rs, inputBitmap);
        Allocation tmpOut = Allocation.createFromBitmap(rs, outputBitmap);
        return outputBitmap;
  2. Copy any image to your drawable folder

  3. Use BlurBuilder in your activity like this:

    protected void onCreate(Bundle savedInstanceState) {
        mContainerView = (LinearLayout) findViewById(;
        Bitmap originalBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.background);
        Bitmap blurredBitmap = BlurBuilder.blur( this, originalBitmap );
        mContainerView.setBackground(new BitmapDrawable(getResources(), blurredBitmap));
  4. Renderscript is included into support v8 enabling this answer down to api 8. To enable it using gradle include these lines into your gradle file (from this answer)

    defaultConfig {
        renderscriptTargetApi *your target api*
        renderscriptSupportModeEnabled true
  5. Result

enter image description here

How to transform numpy.matrix or array to scipy sparse matrix

There are several sparse matrix classes in scipy.

bsr_matrix(arg1[, shape, dtype, copy, blocksize]) Block Sparse Row matrix
coo_matrix(arg1[, shape, dtype, copy]) A sparse matrix in COOrdinate format.
csc_matrix(arg1[, shape, dtype, copy]) Compressed Sparse Column matrix
csr_matrix(arg1[, shape, dtype, copy]) Compressed Sparse Row matrix
dia_matrix(arg1[, shape, dtype, copy]) Sparse matrix with DIAgonal storage
dok_matrix(arg1[, shape, dtype, copy]) Dictionary Of Keys based sparse matrix.
lil_matrix(arg1[, shape, dtype, copy]) Row-based linked list sparse matrix

Any of them can do the conversion.

import numpy as np
from scipy import sparse

(0, 0)  1
(0, 2)  1
(1, 2)  1

See .

Get date from input form within PHP

if (isset($_POST['birthdate'])) {
    $timestamp = strtotime($_POST['birthdate']); 

React Native android build failed. SDK location not found

The problem is that you have misconfigured the environment variables. You have to use (in Windows) the SDK of: C:\Users\YOUR_USERNAME\AppData\Local\Android\Sdk

For more information:

Select: React Native CLI Quickstart in the Android development environment section in point 3. Configure the ANDROID_HOME environment variable

If you do it as you have it right now you must configure each project to use your environment variables and if the project is among several people with their equipment it can cause a problem. If you do it as I have told you, you will not have to configure any project.

submit the form using ajax

What about

  type: 'POST',
  url: $("form").attr("action"),
  data: $("form").serialize(), 
  //or your custom data either as object {foo: "bar", ...} or foo=bar&...
  success: function(response) { ... },

Tensorflow: how to save/restore a model?

Use tf.train.Saver to save a model, remerber, you need to specify the var_list, if you want to reduce the model size. The val_list can be tf.trainable_variables or tf.global_variables.

Handling of non breaking space: <p>&nbsp;</p> vs. <p> </p>

If I understand your issue this should work

&emsp—the em space; this should be a very wide space, typically as much as four real spaces. &ensp—the en space; this should be a somewhat wide space, roughly two regular spaces. &thinsp—this will be a narrow space, even more narrow than a regular space.


PHP Unset Session Variable

If you completely want to clear the session you can use this:


Actually both are not neccessary but it does not hurt.

If you want to clear only a specific part I think you need this:

$_SESSION['Products'] = "";

depending on what you need.

html5 audio player - jquery toggle click play/pause?

Simple Add this Code

        var status = "play"; // Declare global variable

        if (status == 'pause') {
        } else {
            status = 'pause';     

Changing specific text's color using NSMutableAttributedString in Swift

Super easy way to do this.

let text = "This is a colorful attributed string"
let attributedText = 
NSMutableAttributedString.getAttributedString(fromString: text)
attributedText.apply(color: .red, subString: "This")
//Apply yellow color on range
attributedText.apply(color: .yellow, onRange: NSMakeRange(5, 4))

For more detail click here:

How to create a custom-shaped bitmap marker with Android map API v2

From lambda answer, I have made something closer to the requirements.

boolean imageCreated = false;

Bitmap bmp = null;
Marker currentLocationMarker;
private void doSomeCustomizationForMarker(LatLng currentLocation) {
    if (!imageCreated) {
        imageCreated = true;
        Bitmap.Config conf = Bitmap.Config.ARGB_8888;
        bmp = Bitmap.createBitmap(400, 400, conf);
        Canvas canvas1 = new Canvas(bmp);

        Paint color = new Paint();

        BitmapFactory.Options opt = new BitmapFactory.Options();
        opt.inMutable = true;

        Bitmap imageBitmap=BitmapFactory.decodeResource(getResources(),
        Bitmap resized = Bitmap.createScaledBitmap(imageBitmap, 320, 320, true);
        canvas1.drawBitmap(resized, 40, 40, color);

        canvas1.drawText("Le Messi", 30, 40, color);

        currentLocationMarker = mMap.addMarker(new MarkerOptions().position(currentLocation)
                // Specifies the anchor to be at a particular point in the marker image.
                .anchor(0.5f, 1));
    } else {


How to print full stack trace in exception?

Recommend to use LINQPad related nuget package, then you can use exceptionInstance.Dump().

enter image description here

For .NET core:

  • Install LINQPad.Runtime

For .NET framework 4 etc.

  • Install LINQPad

Sample code:

using System;
using LINQPad;

namespace csharp_Dump_test
    public class Program
        public static void Main()
            catch (Exception ex)

        private static void dosome()
            throw new Exception("Unable.");

Running result: enter image description here

LinqPad nuget package is the most awesome tool for printing exception stack information. May it be helpful for you.

How do I execute external program within C code in linux with arguments?

For a simple way, use system():

#include <stdlib.h>
int status = system("./foo 1 2 3");

system() will wait for foo to complete execution, then return a status variable which you can use to check e.g. exitcode (the command's exitcode gets multiplied by 256, so divide system()'s return value by that to get the actual exitcode: int exitcode = status / 256).

The manpage for wait() (in section 2, man 2 wait on your Linux system) lists the various macros you can use to examine the status, the most interesting ones would be WIFEXITED and WEXITSTATUS.

Alternatively, if you need to read foo's standard output, use popen(3), which returns a file pointer (FILE *); interacting with the command's standard input/output is then the same as reading from or writing to a file.

Only get hash value using md5sum (without filename)

md5=$(md5sum < index.html | head -c -4)

Can I set state inside a useEffect hook

Effects are always executed after the render phase is completed even if you setState inside the one effect, another effect will read the updated state and take action on it only after the render phase.

Having said that its probably better to take both actions in the same effect unless there is a possibility that b can change due to reasons other than changing a in which case too you would want to execute the same logic

How to show particular image as thumbnail while implementing share on Facebook?

Facebook uses og:tags and the Open Graph Protocol to decipher what information to display when previewing your URL in a share dialog or in a news feed on facebook.

The og:tags contain information such as :

  • The title of the page
  • The type of page
  • The URL
  • The websites name
  • A description of the page
  • Facebook user_id's of administrators of the page ( on facebook )

Here is an example ( taken from the facebook documentation ) of some og:tags

<meta property="og:title" content="The Rock"/>
<meta property="og:type" content="movie"/>
<meta property="og:url" content=""/>
<meta property="og:image" content=""/>

Once you have implemented the correct markup of the og:tags and set their values, you can test how facebook will view your URL by using the Facebook Debugger. The debugger tool will also highlight any problems it finds with the og:tags on the page or lack there-of.

One thing to keep in mind is that facebook does do some caching with regard to this information, so in order for changes to take effect your page will have t be scraped as stated in the documentation :

Editing Meta Tags

You can update the attributes of your page by updating your page's tags. Note that og:title and og:type are only editable initially - after your page receives 50 likes the title becomes fixed, and after your page receives 10,000 likes the type becomes fixed. These properties are fixed to avoid surprising users who have liked the page already. Changing the title or type tags after these limits are reached does nothing, your page retains the original title and type.

For the changes to be reflected on Facebook, you must force your page to be scraped. The page is scraped when an admin for the page clicks the Like button or when the URL is entered into the Facebook URL Linter Facebook Debugger...

Parse query string in JavaScript

If you know that you will only have that one querystring variable you can simply do:

var dest =^.*?\=/, '');

Read connection string from web.config

Add System.Configuration as a reference then:

 using System.Configuration;


 string conn = 

Textarea to resize based on content length

You can achieve this by using a span and a textarea.

You have to update the span with the text in textarea each time the text is changed. Then set the css width and height of the textarea to the span's clientWidth and clientHeight property.


.textArea {
    border: #a9a9a9 1px solid;
    overflow: hidden;
    width:  expression( document.getElementById("spnHidden").clientWidth );
    height: expression( document.getElementById("spnHidden").clientHeight );

mysql datetime comparison

...this is obviously performing a 'string' comparison

No - if the date/time format matches the supported format, MySQL performs implicit conversion to convert the value to a DATETIME, based on the column it is being compared to. Same thing happens with:

WHERE int_column = '1'

...where the string value of "1" is converted to an INTeger because int_column's data type is INT, not CHAR/VARCHAR/TEXT.

If you want to explicitly convert the string to a DATETIME, the STR_TO_DATE function would be the best choice:

WHERE expires_at <= STR_TO_DATE('2010-10-15 10:00:00', '%Y-%m-%d %H:%i:%s')

SQL is null and = null

I think that equality is something that can be absolutely determined. The trouble with null is that it's inherently unknown. Null combined with any other value is null - unknown. Asking SQL "Is my value equal to null?" would be unknown every single time, even if the input is null. I think the implementation of IS NULL makes it clear.

Keeping it simple and how to do multiple CTE in a query

You can have multiple CTEs in one query, as well as reuse a CTE:

WITH    cte1 AS
        SELECT  1 AS id
        cte2 AS
        SELECT  2 AS id
FROM    cte1
FROM    cte2
FROM    cte1

Note, however, that SQL Server may reevaluate the CTE each time it is accessed, so if you are using values like RAND(), NEWID() etc., they may change between the CTE calls.

How do I disable and re-enable a button in with javascript?

you can try with

document.getElementById('btn').disabled = !this.checked"

<input type="submit" name="btn"  id="btn" value="submit" disabled/>_x000D_
<input type="checkbox"  onchange="document.getElementById('btn').disabled = !this.checked"/>

How to write character & in android strings.xml

This is a my issues, my solution is as following: Use &gt; for <, &lt;for > , &amp; for & ,"'" for ' , &quot for \"\"

How to obtain a QuerySet of all rows, with specific fields for each one of them?

Employees.objects.values_list('eng_name', flat=True)

That creates a flat list of all eng_names. If you want more than one field per row, you can't do a flat list: this will create a list of tuples:

Employees.objects.values_list('eng_name', 'rank')

How to use HTTP GET in PowerShell?

Downloading Wget is not necessary; the .NET Framework has web client classes built in.

$wc = New-Object system.Net.WebClient;
$sms = Read-Host "Enter SMS text";
$sms = [System.Web.HttpUtility]::UrlEncode($sms);
$smsResult = $wc.downloadString("http://smsserver/SNSManager/msgSend.jsp?uid&to=smartsms:*+001XXXXXX&msg=$sms&encoding=windows-1255")

How to create Select List for Country and States/province in MVC

So many ways to do this... for #NetCore use Lib..

    using System;
    using System.Collections.Generic;
    using System.Linq; // only required when .AsEnumerable() is used
    using System.ComponentModel.DataAnnotations;
    using Microsoft.AspNetCore.Mvc.Rendering;


namespace MyProject.Models
  public class MyModel
    [Display(Name = "State")]
    public string StatePick { get; set; }
    public string state { get; set; }
    [StringLength(35, ErrorMessage = "State cannot be longer than 35 characters.")]
    public SelectList StateList { get; set; }


namespace MyProject.Controllers
    /// <summary>
    /// create SelectListItem from strings
    /// </summary>
    /// <param name="isValue">defaultValue is SelectListItem.Value is true, SelectListItem.Text if false</param>
    /// <returns></returns>
    private SelectListItem newItem(string value, string text, string defaultValue = "", bool isValue = false)
        SelectListItem ss = new SelectListItem();
        ss.Text = text;
        ss.Value = value;

        // select default by Value or Text
        if (isValue && ss.Value == defaultValue || !isValue && ss.Text == defaultValue)
            ss.Selected = true;

        return ss;

    /// <summary>
    /// this pulls the state name from _context and sets it as the default for the selectList
    /// </summary>
    /// <param name="myState">sets default value for list of states</param>
    /// <returns></returns>
    private SelectList getStateList(string myState = "")
        List<SelectListItem> states = new List<SelectListItem>();
        SelectListItem chosen = new SelectListItem();

        // set default selected state to OHIO
        string defaultValue = "OH";
        if (!string.IsNullOrEmpty(myState))
            defaultValue = myState;

            states.Add(newItem("AL", "Alabama", defaultValue, true));
            states.Add(newItem("AK", "Alaska", defaultValue, true));
            states.Add(newItem("AZ", "Arizona", defaultValue, true));
            states.Add(newItem("AR", "Arkansas", defaultValue, true));
            states.Add(newItem("CA", "California", defaultValue, true));
            states.Add(newItem("CO", "Colorado", defaultValue, true));
            states.Add(newItem("CT", "Connecticut", defaultValue, true));
            states.Add(newItem("DE", "Delaware", defaultValue, true));
            states.Add(newItem("DC", "District of Columbia", defaultValue, true));
            states.Add(newItem("FL", "Florida", defaultValue, true));
            states.Add(newItem("GA", "Georgia", defaultValue, true));
            states.Add(newItem("HI", "Hawaii", defaultValue, true));
            states.Add(newItem("ID", "Idaho", defaultValue, true));
            states.Add(newItem("IL", "Illinois", defaultValue, true));
            states.Add(newItem("IN", "Indiana", defaultValue, true));
            states.Add(newItem("IA", "Iowa", defaultValue, true));
            states.Add(newItem("KS", "Kansas", defaultValue, true));
            states.Add(newItem("KY", "Kentucky", defaultValue, true));
            states.Add(newItem("LA", "Louisiana", defaultValue, true));
            states.Add(newItem("ME", "Maine", defaultValue, true));
            states.Add(newItem("MD", "Maryland", defaultValue, true));
            states.Add(newItem("MA", "Massachusetts", defaultValue, true));
            states.Add(newItem("MI", "Michigan", defaultValue, true));
            states.Add(newItem("MN", "Minnesota", defaultValue, true));
            states.Add(newItem("MS", "Mississippi", defaultValue, true));
            states.Add(newItem("MO", "Missouri", defaultValue, true));
            states.Add(newItem("MT", "Montana", defaultValue, true));
            states.Add(newItem("NE", "Nebraska", defaultValue, true));
            states.Add(newItem("NV", "Nevada", defaultValue, true));
            states.Add(newItem("NH", "New Hampshire", defaultValue, true));
            states.Add(newItem("NJ", "New Jersey", defaultValue, true));
            states.Add(newItem("NM", "New Mexico", defaultValue, true));
            states.Add(newItem("NY", "New York", defaultValue, true));
            states.Add(newItem("NC", "North Carolina", defaultValue, true));
            states.Add(newItem("ND", "North Dakota", defaultValue, true));
            states.Add(newItem("OH", "Ohio", defaultValue, true));
            states.Add(newItem("OK", "Oklahoma", defaultValue, true));
            states.Add(newItem("OR", "Oregon", defaultValue, true));
            states.Add(newItem("PA", "Pennsylvania", defaultValue, true));
            states.Add(newItem("RI", "Rhode Island", defaultValue, true));
            states.Add(newItem("SC", "South Carolina", defaultValue, true));
            states.Add(newItem("SD", "South Dakota", defaultValue, true));
            states.Add(newItem("TN", "Tennessee", defaultValue, true));
            states.Add(newItem("TX", "Texas", defaultValue, true));
            states.Add(newItem("UT", "Utah", defaultValue, true));
            states.Add(newItem("VT", "Vermont", defaultValue, true));
            states.Add(newItem("VA", "Virginia", defaultValue, true));
            states.Add(newItem("WA", "Washington", defaultValue, true));
            states.Add(newItem("WV", "West Virginia", defaultValue, true));
            states.Add(newItem("WI", "Wisconsin", defaultValue, true));
            states.Add(newItem("WY", "Wyoming", defaultValue, true));

            foreach (SelectListItem state in states)
                if (state.Selected)
                    chosen = state;
        catch (Exception err)
            string ss = "ERR!   " + err.Source + "   " + err.GetType().ToString() + "\r\n" + err.Message.Replace("\r\n", "   ");
            ss = this.sendError("Online getStateList Request", ss, _errPassword);
            // return error

        // .AsEnumerable() is not required in the pass.. it is an extension of Linq
        SelectList myList = new SelectList(states.AsEnumerable(), "Value", "Text", chosen);

        object val = myList.SelectedValue;

        return myList;

    public ActionResult pickState(MyModel pData)
        if (pData.StateList == null)
            if (String.IsNullOrEmpty(pData.StatePick)) // state abbrev, value collected onchange
                pData.StateList = getStateList();
                pData.StateList = getStateList(pData.StatePick);

            // assign values to state list items
                SelectListItem si = (SelectListItem)pData.StateList.SelectedValue;
                pData.state = si.Value;
                pData.StatePick = si.Value;
            catch { }
    return View(pData);


@model MyProject.Models.MyModel

ViewBag.Title = "United States of America";
Layout = "~/Views/Shared/_Layout.cshtml";
<h2>@ViewBag.Title - Where are you...</h2>

@using (Html.BeginForm()) {


    <div class="editor-label">
        @Html.DisplayNameFor(model => model.state)
    <div class="display-field">            
        @Html.DropDownListFor(m => m.StatePick, Model.StateList, new { OnChange = "state.value = this.value;" })
        @Html.EditorFor(model => model.state)
        @Html.ValidationMessageFor(model => model.StateList)

@Html.ActionLink("Back to List", "Index")

how to insert a new line character in a string to PrintStream then use a scanner to re-read the file

The linefeed character \n is not the line separator in certain operating systems (such as windows, where it's "\r\n") - my suggestion is that you use \r\n instead, then it'll both see the line-break with only \n and \r\n, I've never had any problems using it.

Also, you should look into using a StringBuilder instead of concatenating the String in the while-loop at BookCatalog.toString(), it is a lot more effective. For instance:

public String toString() {
        BookNode current = front;
        StringBuilder sb = new StringBuilder();
        while (current!=null){
            sb.append(current.getData().toString()+"\r\n ");
            current = current.getNext();
        return sb.toString();

Angular redirect to login page

Following the awesome answers above I would also like to CanActivateChild: guarding child routes. It can be used to add guard to children routes helpful for cases like ACLs

It goes like this

src/app/auth-guard.service.ts (excerpt)

import { Injectable }       from '@angular/core';
import {
  CanActivate, Router,
}                           from '@angular/router';
import { AuthService }      from './auth.service';

export class AuthGuard implements CanActivate, CanActivateChild {
  constructor(private authService: AuthService, private router:     Router) {}

  canActivate(route: ActivatedRouteSnapshot, state:    RouterStateSnapshot): boolean {
    let url: string = state.url;
    return this.checkLogin(url);

  canActivateChild(route: ActivatedRouteSnapshot, state:  RouterStateSnapshot): boolean {
    return this.canActivate(route, state);

/* . . . */

src/app/admin/admin-routing.module.ts (excerpt)

const adminRoutes: Routes = [
    path: 'admin',
    component: AdminComponent,
    canActivate: [AuthGuard],
    children: [
        path: '',
        canActivateChild: [AuthGuard],
        children: [
          { path: 'crises', component: ManageCrisesComponent },
          { path: 'heroes', component: ManageHeroesComponent },
          { path: '', component: AdminDashboardComponent }

  imports: [
  exports: [
export class AdminRoutingModule {}

This is taken from!#can-activate-guard

Cannot import XSSF in Apache POI

I needed the following files for my implementation:

  • poi-ooxml-schemas-3.14.20160307.jar
  • commons-codec-1.10.jar (this was in "lib" folder of the zip file you get from apache)
  • curvesapi-1.03.jar (in "ooxml-lib" folder)
  • poi-3.14-20160307.jar
  • poi-ooxml-3.14-20160307.jar
  • xmlbeans-2.6.0.jar (in "ooxml-lib" folder)

(though honestly, I'm not completely sure they are all necessary...) It's a little confusing because they are packaged that way. I needed to place them manually in my own "lib" folder and then add the references...

Maven always seems to download more than I need, so I always place libaries/dlls and things like that manually.

Increment value in mysql update query

Hope I'm not going offtopic on my first post, but I'd like to expand a little on the casting of integer to string as some respondents appear to have it wrong.

Because the expression in this query uses an arithmetic operator (the plus symbol +), MySQL will convert any strings in the expression to numbers.

To demonstrate, the following will produce the result 6:

SELECT ' 05.05 '+'.95';

String concatenation in MySQL requires the CONCAT() function so there is no ambiguity here and MySQL converts the strings to floats and adds them together.

I actually think the reason the initial query wasn't working is most likely because the $points variable was not in fact set to the user's current points. It was either set to zero, or was unset: MySQL will cast an empty string to zero. For illustration, the following will return 0:


Like I said, I hope I'm not being too off-topic. I agree that Daan and Tomas have the best solutions for this particular problem.

How might I find the largest number contained in a JavaScript array?

Use Array.reduce:

[0,1,2,3,4].reduce(function(previousValue, currentValue){
  return Math.max(previousValue,currentValue);

What exactly is a Maven Snapshot and why do we need it?

The three others answers provide you a good vision of what a -SNAPSHOT version is. I just wanted to add some information regarding the behavior of Maven when it finds a SNAPSHOT dependency.

When you build an application, Maven will search for dependencies in the local repository. If a stable version is not found there, it will search the remote repositories (defined in settings.xml or pom.xml) to retrieve this dependency. Then, it will copy it into the local repository, to make it available for the next builds.

For example, a foo-1.0.jar library is considered as a stable version, and if Maven finds it in the local repository, it will use this one for the current build.

Now, if you need a foo-1.0-SNAPSHOT.jar library, Maven will know that this version is not stable and is subject to changes. That's why Maven will try to find a newer version in the remote repositories, even if a version of this library is found on the local repository. However, this check is made only once per day. That means that if you have a foo-1.0-20110506.110000-1.jar (i.e. this library has been generated on 2011/05/06 at 11:00:00) in your local repository, and if you run the Maven build again the same day, Maven will not check the repositories for a newer version.

Maven provides you a way to change this update policy in your repository definition:


where XXX can be:

  • always: Maven will check for a newer version on every build;
  • daily, the default value;
  • interval:XXX: an interval in minutes (XXX)
  • never: Maven will never try to retrieve another version. It will do that only if it doesn't exist locally. With the configuration, SNAPSHOT version will be handled as the stable libraries.

(model of the settings.xml can be found here)

babel-loader jsx SyntaxError: Unexpected token

I ran into a similar issue when migrating from babel 5 to babel 6.

I was just running babel to compile the src to lib folder babel src --out-dir lib

I will share my setup for babel 6:

Ensure you have the following babel 6 devDependencies installed

"babel-core": "^6.7.6",
"babel-loader": "^6.2.4",
"babel-preset-es2015": "^6.6.0",
"babel-preset-react": "^6.5.0",
"babel-preset-stage-0": "^6.5.0"

Add your .babelrc file to the project:

  "presets": ["es2015", "stage-0", "react"]

How to get height of Keyboard?

The method by ZAFAR007 updated for Swift 5 in Xcode 10

override func viewDidLoad() {

    NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)


@objc func keyboardWillShow(notification: NSNotification) {

    if let keyboardSize = (notification.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
        let keyboardHeight : Int = Int(keyboardSize.height)


How to clear browser cache with php?

header("Cache-Control: no-cache, must-revalidate");
header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Content-Type: application/xml; charset=utf-8");

Assign result of dynamic sql to variable

Most of these answers use sp_executesql as the solution to this problem. I have found that there are some limitations when using sp_executesql, which I will not go into, but I wanted to offer an alternative using EXEC(). I am using SQL Server 2008 and I know that some of the objects I am using in this script are not available in earlier versions of SQL Server so be wary.

DECLARE @CountResults TABLE (CountReturned INT)
    @SqlStatement VARCHAR(8000) = 'SELECT COUNT(*) FROM table'
    , @Count INT

INSERT @CountResults

SET @Count = (SELECT CountReturned FROM @CountResults)

Are PHP short tags acceptable to use?

They're not recommended because it's a PITA if you ever have to move your code to a server where it's not supported (and you can't enable it). As you say, lots of shared hosts do support shorttags but "lots" isn't all of them. If you want to share your scripts, it's best to use the full syntax.

I agree that <? and <?= are easier on programmers than <?php and <?php echo but it is possible to do a bulk find-and-replace as long as you use the same form each time (and don't chuck in spaces (eg: <? php or <? =)

I don't buy readability as a reason at all. Most serious developers have the option of syntax highlighting available to them.

As ThiefMaster mentions in the comments, as of PHP 5.4, <?= ... ?> tags are supported everywhere, regardless of shorttags settings. This should mean they're safe to use in portable code but that does mean there's then a dependency on PHP 5.4+. If you want to support pre-5.4 and can't guarantee shorttags, you'll still need to use <?php echo ... ?>.

Also, you need to know that ASP tags <% , %> , <%= , and script tag are removed from PHP 7. So if you would like to support long-term portable code and would like switching to the most modern tools consider changing that parts of code.

How can I label points in this scatterplot?

You should use labels attribute inside plot function and the value of this attribute should be the vector containing the values that you want for each point to have.

How to get just the responsive grid from Bootstrap 3?

It looks like you can download just the grid now on Bootstrap 4s new download features.

MS SQL compare dates?

Try This:


declare @Date1 datetime
declare @Date2 datetime

declare @chkYear int
declare @chkMonth int
declare @chkDay int
declare @chkHour int
declare @chkMinute int
declare @chkSecond int
declare @chkMiliSecond int

set @Date1='2010-12-31 15:13:48.593'
set @Date2='2010-12-31 00:00:00.000'

set @chkYear=datediff(yyyy,@Date1,@Date2)
set @chkMonth=datediff(mm,@Date1,@Date2)
set @chkDay=datediff(dd,@Date1,@Date2)
set @chkHour=datediff(hh,@Date1,@Date2)
set @chkMinute=datediff(mi,@Date1,@Date2)
set @chkSecond=datediff(ss,@Date1,@Date2)
set @chkMiliSecond=datediff(ms,@Date1,@Date2)

if @chkYear=0 AND @chkMonth=0 AND @chkDay=0 AND @chkHour=0 AND @chkMinute=0 AND @chkSecond=0 AND @chkMiliSecond=0
        Print 'Both Date is Same'
        Print 'Both Date is not Same'

Performance differences between ArrayList and LinkedList

I want to add an additional piece of information her about the difference in performance.

We already know that due to the fact that ArrayList implementation is backed by an Object[] it's supports random access and dynamic resizing and LinkedList implementation uses references to head and tail to navigate it. It has no random access capabilities, but it supports dynamic resizing as well.

The first thing is that with an ArrayList, you can immediately access the index, whereas with a LinkedList, you have iterate down the object chain.

Secondly, inserting into ArrayList is generally slower because it has to grow once you hit its boundaries. It will have to create a new bigger array, and copy data from the original one.

But the interesting thing is that when you create an ArrayList that is already huge enough to fit all your inserts it will obviously not involve any array copying operations. Adding to it will be even faster than with LinkedList because LinkedList will have to deal with its pointers, while huge ArrayList just sets value at given index.

enter image description here

Check out for more ArrayList and LinkedList differences.

How to print strings with line breaks in java

Use String buffer.

  final StringBuffer mText = new StringBuffer("SHOP MA\n"
        + "----------------------------\n"
        + "Pannampitiya\n"
        + "09-10-2012 harsha  no: 001\n"
        + "No  Item  Qty  Price  Amount\n"
        + "1 Bread 1 50.00  50.00\n"
        + "____________________________\n");

Delete commit on gitlab

We've had similar problem and it was not enough to only remove commit and force push to GitLab.
It was still available in GitLab interface using url:<group>/<project>/commit/<commit hash>

We've had to remove project from GitLab and recreate it to get rid of this commit in GitLab UI.

Difference between jQuery parent(), parents() and closest() functions

The differences between the two, though subtle, are significant:


  • Begins with the current element
  • Travels up the DOM tree until it finds a match for the supplied selector
  • The returned jQuery object contains zero or one element


  • Begins with the parent element
  • Travels up the DOM tree to the document's root element, adding each ancestor element to a temporary collection; it then filters that collection based on a selector if one is supplied
  • The returned jQuery object contains zero, one, or multiple elements

From jQuery docs

Java Try Catch Finally blocks without Catch

how does the try block work if it encounters an exception or anything throwable

The exception is thrown out of the block, just as in any other case where it's not caught.

The finally block is executed regardless of how the try block is exited -- regardless whether there are any catches at all, regardless of whether there is a matching catch.

The catch blocks and the finally are orthogonal parts of the try block. You can have either or both. With Java 7, you'll be able to have neither!

Explanation of the UML arrows

For quick reference along with clear concise examples, Allen Holub's UML Quick Reference is excellent:

(There are quite a few specific examples of arrows and pointers in the first column of a table, with descriptions in the second column.)

test if event handler is bound to an element in jQuery

With reference to SJG's answer and from

As of jQuery version 1.7, the off() method is the new replacement for the unbind(), die() and undelegate() methods. This method brings a lot of consistency to the API, and we recommend that you use this method, as it simplifies the jQuery code base.

This gives:




Handling InterruptedException in Java

I would say in some cases it's ok to do nothing. Probably not something you should be doing by default, but in case there should be no way for the interrupt to happen, I'm not sure what else to do (probably logging error, but that does not affect program flow).

One case would be in case you have a task (blocking) queue. In case you have a daemon Thread handling these tasks and you do not interrupt the Thread by yourself (to my knowledge the jvm does not interrupt daemon threads on jvm shutdown), I see no way for the interrupt to happen, and therefore it could be just ignored. (I do know that a daemon thread may be killed by the jvm at any time and therefore are unsuitable in some cases).

EDIT: Another case might be guarded blocks, at least based on Oracle's tutorial at:

Where are SQL Server connection attempts logged?

You can enable connection logging. For SQL Server 2008, you can enable Login Auditing. In SQL Server Management Studio, open SQL Server Properties > Security > Login Auditing select "Both failed and successful logins".

Make sure to restart the SQL Server service.

Once you've done that, connection attempts should be logged into SQL's error log. The physical logs location can be determined here.

ViewDidAppear is not called when opening app from background

Swift 4.2. version

Register with the NotificationCenter in viewDidLoad to be notified when the app returns from background

NotificationCenter.default.addObserver(self, selector: #selector(doSomething), name: UIApplication.willEnterForegroundNotification, object: nil)

Implement the method that should be called.

@objc private func doSomething() {
    // Do whatever you want, for example update your view.

You can remove the observer once the ViewController is destroyed. This is only required below iOS9 and macOS 10.11

deinit {

How do check if a PHP session is empty?

You could use the count() function to see how many entries there are in the $_SESSION array. This is not good practice. You should instead set the id of the user (or something similar) to check wheter the session was initialised or not.

if( !isset($_SESSION['uid']) )
    die( "Login required." );

(Assuming you want to check if someone is logged in)

Check if a string is a palindrome

In C# :

public bool EhPalindromo(string text)
 var reverseText = string.Join("", text.ToLower().Reverse());
 return reverseText == text;

Can a variable number of arguments be passed to a function?

def f(dic):
    if 'a' in dic:
        print dic['a'],
    else: print 'None',

    if 'b' in dic:
        print dic['b'],
    else: print 'None',

    if 'c' in dic:
        print dic['c'],
    else: print 'None',

the above code will output

None None None
20 None 30
20 red 30

This is as good as passing variable arguments by means of a dictionary

Operator overloading on class templates

This way works:

class A
    struct Wrap
        A& a;
        Wrap(A& aa) aa(a) {}
        operator int() { return a.value; }
        operator std::string() { stringstream ss; ss << a.value; return ss.str(); } 
    Wrap operator*() { return Wrap(*this); }

remove all special characters in java

Your problem is that the indices returned by match.start() correspond to the position of the character as it appeared in the original string when you matched it; however, as you rewrite the string c every time, these indices become incorrect.

The best approach to solve this is to use replaceAll, for example:

        System.out.println(c.replaceAll("[^a-zA-Z0-9]", ""));

ASP.NET Temporary files cleanup

Yes, it's safe to delete these, although it may force a dynamic recompilation of any .NET applications you run on the server.

For background, see the Understanding ASP.NET dynamic compilation article on MSDN.

How to split a string with any whitespace chars as delimiters

Also you may have a UniCode non-breaking space xA0...

String[] elements = s.split("[\\s\\xA0]+"); //include uniCode non-breaking

How to install Python packages from the tar.gz file without using pip install

For those of you using python3 you can use:

python3 install

Are one-line 'if'/'for'-statements good Python style?

You could do all of that in one line by omitting the example variable:

if "exam" in "example": print "yes!"

How to get the clicked link's href with jquery?

You're looking for $(this).attr("href");

What is the full path to the Packages folder for Sublime text 2 on Mac OS Lion

/Users/{user}/Library/Application Support/Sublime Text 2/Packages

Get to it quickly from within Sublime via the menu at Sublime Text 2... Preferences... Browse Packages

In Visual Studio Code How do I merge between two local branches?

I found this extension for VS code called Git Merger. It adds Git: Merge from to the commands.

Overlay a background-image with an rgba background-color

I've gotten the following to work:

html {
      url('bgimage.jpg') no-repeat center center fixed;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;

The above will produce a nice opaque blue overlay.

Filter by Dates in SQL

If your dates column does not contain time information, you could get away with:

WHERE dates BETWEEN '20121211' and '20121213'

However, given your dates column is actually datetime, you want this

WHERE dates >= '20121211'
  AND dates < '20121214'  -- i.e. 00:00 of the next day

Another option for SQL Server 2008 onwards that retains SARGability (ability to use index for good performance) is:

WHERE CAST(dates as date) BETWEEN '20121211' and '20121213'

Note: always use ISO-8601 format YYYYMMDD with SQL Server for unambiguous date literals.

Mockito How to mock and assert a thrown exception?

BDD Style Solution (Updated to Java 8)

Mockito alone is not the best solution for handling exceptions, use Mockito with Catch-Exception

Mockito + Catch-Exception + AssertJ

given( MyException());

when(() ->;


Sample code


Return a value if no rows are found in Microsoft tSQL

Something like:

if exists (select top 1 * from Sites S where S.Id IS NOT NULL AND S.Status = 1 AND (S.WebUserId = @WebUserId OR S.AllowUploads = 1))
    select 1
    select 0

An error occurred while collecting items to be installed (Access is denied)

Installig Eclispe ADT from market place solved this problem for me.

CURL to pass SSL certifcate and password

Should be:

curl --cert certificate_file.pem:password

how to read value from string.xml in android?

Solution 1

Context context;
String mess = context.getString(R.string.mess_1)

Solution 2

String mess = getString(R.string.mess_1)

Javascript / Chrome - How to copy an object from the webkit inspector as code

  1. Right-click an object in Chrome's console and select Store as Global Variable from the context menu. It will return something like temp1 as the variable name.

  2. Chrome also has a copy() method, so copy(temp1) in the console should copy that object to your clipboard.

Copy Javascript Object in Chrome DevTools

Note on Recursive Objects: If you're trying to copy a recursive object, you will get [object Object]. The way out is to copy(JSON.stringify(temp1)) , the object will be fully copied to your clipboard as a valid JSON, so you'd be able to format it as you wish, using one of many resources.

How to Call VBA Function from Excel Cells?

Here's the answer

Steps to follow:

  1. Open the Visual Basic Editor. In Excel, hit Alt+F11 if on Windows, Fn+Option+F11 if on a Mac.

  2. Insert a new module. From the menu: Insert -> Module (Don't skip this!).

  3. Create a Public function. Example:

    Public Function findArea(ByVal width as Double, _
                             ByVal height as Double) As Double
        ' Return the area
        findArea = width * height
    End Function
  4. Then use it in any cell like you would any other function: =findArea(B12,C12).

InvalidKeyException : Illegal Key Size - Java code throwing exception for encryption class - how to fix?

Add below code in your client code :

static {
    Security.insertProviderAt(new BouncyCastleProvider(),1);

with this there is no need to add any entry in file.

Two column div layout with fluid left and fixed right column

Here's a solution (and it has some quirks, but let me know if you notice them and that they're a concern):

    <div style="width:200px;float:left;display:inline-block;">
        Hello world
    <div style="margin-left:200px;">
        Hello world

Free easy way to draw graphs and charts in C++?

Cern's ROOT produces some pretty nice stuff, I use it to display Neural Network data a lot.

How to slice an array in Bash

See the Parameter Expansion section in the Bash man page. A[@] returns the contents of the array, :1:2 takes a slice of length 2, starting at index 1.

A=( foo bar "a  b c" 42 )
C=("${A[@]:1}")       # slice to the end of the array
echo "${B[@]}"        # bar a  b c
echo "${B[1]}"        # a  b c
echo "${C[@]}"        # bar a  b c 42
echo "${C[@]: -2:2}"  # a  b c 42 # The space before the - is necesssary

Note that the fact that "a b c" is one array element (and that it contains an extra space) is preserved.

import module from string variable

I developed these 3 useful functions:

def loadModule(moduleName):
    module = None
        import sys
        del sys.modules[moduleName]
    except BaseException as err:
        import importlib
        module = importlib.import_module(moduleName)
    except BaseException as err:
        serr = str(err)
        print("Error to load the module '" + moduleName + "': " + serr)
    return module

def reloadModule(moduleName):
    module = loadModule(moduleName)
    moduleName, modulePath = str(module).replace("' from '", "||").replace("<module '", '').replace("'>", '').split("||")
    if (modulePath.endswith(".pyc")):
        import os
        module = loadModule(moduleName)
    return module

def getInstance(moduleName, param1, param2, param3):
    module = reloadModule(moduleName)
    instance = eval("module." + moduleName + "(param1, param2, param3)")
    return instance

And everytime I want to reload a new instance I just have to call getInstance() like this:

myInstance = getInstance("MyModule", myParam1, myParam2, myParam3)

Finally I can call all the functions inside the new Instance:


The only specificity here is to customize the params list (param1, param2, param3) of your instance.

Unstage a deleted file in git

The answers to your two questions are related. I'll start with the second:

Once you have staged a file (often with git add, though some other commands implicitly stage the changes as well, like git rm) you can back out that change with git reset -- <file>.

In your case you must have used git rm to remove the file, which is equivalent to simply removing it with rm and then staging that change. If you first unstage it with git reset -- <file> you can then recover it with git checkout -- <file>.

Change the bullet color of list

I would recommend you to use background-image instead of default list.

.listStyle {
    list-style: none;
    background: url(image_path.jpg) no-repeat left center;
    padding-left: 30px;
    width: 20px;
    height: 20px;

Or, if you don't want to use background-image as bullet, there is an option to do it with pseudo element:

    list-style: none;
    margin: 0;
    padding: 0;
.liststyle:before {
    content: "• ";
    color: red; /* or whatever color you prefer */
    font-size: 20px;/* or whatever the bullet size you prefer */

Use jQuery to change a second select list based on the first select list option

I wanted to make a version of this that uses $.getJSON() from a separate JSON file.

Demo: here


$(document).ready(function () {
    "use strict";

    var selectData, $states;

    function updateSelects() {
        var cities = $.map(selectData[this.value], function (city) {
            return $("<option />").text(city);

    $.getJSON("updateSelect.json", function (data) {
        var state;
        selectData = data;
        $states = $("#us_states").on("change", updateSelects);
        for (state in selectData) {
            $("<option />").text(state).appendTo($states);


<!DOCTYPE html>
    <script src=""></script>
    <select id="us_states"></select>
    <select id="city_names"></select>
    <script type="text/javascript" src="updateSelect.js"></script>


    "NE": [
    "CA": [
    "MI": [

React component initialize state from props

If you directly init state from props, it will shows warning in React 16.5 (5th September 2018)

How to configure slf4j-simple

It's either through system property


or file on the classpath

see for details

MIN and MAX in C

This is a late answer, due to a fairly recent development. Since the OP accepted the answer that relies on a non-portable GCC (and clang) extension typeof - or __typeof__ for 'clean' ISO C - there's a better solution available as of gcc-4.9.

#define max(x,y) ( \
    { __auto_type __x = (x); __auto_type __y = (y); \
      __x > __y ? __x : __y; })

The obvious benefit of this extension is that each macro argument is only expanded once, unlike the __typeof__ solution.

__auto_type is a limited form of C++11's auto. It cannot (or should not?) be used in C++ code, though there's no good reason not to use the superior type inference capabilities of auto when using C++11.

That said, I assume there are no issues using this syntax when the macro is included in an extern "C" { ... } scope; e.g., from a C header. AFAIK, this extension has not found its way info clang

How to configure Glassfish Server in Eclipse manually

For Eclipse Luna

Go to Help>Eclipse MarketPlace> Search for GlassFish Tools and install it.

Restart Eclipse.

Now go to servers>new>server and you will find Glassfish server.

gpg: no valid OpenPGP data found

I too got the same error, when I did this behind a proxy. But after I exported the following from a terminal and re-tried the same command, the problem got resolved:

export http_proxy="http://username:password@proxy_ip_addr:port/"
export https_proxy="https://username:password@proxy_ip_addr:port/"

convert nan value to zero

For your purposes, if all the items are stored as str and you just use sorted as you are using and then check for the first element and replace it with '0'

>>> l1 = ['88','NaN','67','89','81']
>>> n = sorted(l1,reverse=True)
['NaN', '89', '88', '81', '67']
>>> import math
>>> if math.isnan(float(n[0])):
...     n[0] = '0'
>>> n
['0', '89', '88', '81', '67']

File being used by another process after using File.Create()

The File.Create method creates the file and opens a FileStream on the file. So your file is already open. You don't really need the file.Create method at all:

string filePath = @"c:\somefilename.txt";
using (StreamWriter sw = new StreamWriter(filePath, true))
    //write to the file

The boolean in the StreamWriter constructor will cause the contents to be appended if the file exists.

Reading a plain text file in Java

You can use readAllLines and the join method to get whole file content in one line:

String str = String.join("\n",Files.readAllLines(Paths.get("e:\\text.txt")));

It uses UTF-8 encoding by default, which reads ASCII data correctly.

Also you can use readAllBytes:

String str = new String(Files.readAllBytes(Paths.get("e:\\text.txt")), StandardCharsets.UTF_8);

I think readAllBytes is faster and more precise, because it does not replace new line with \n and also new line may be \r\n. It is depending on your needs which one is suitable.

How to get integer values from a string in Python?

if you have multiple sets of numbers then this is another option

>>> import re
>>> print(re.findall('\d+', 'xyz123abc456def789'))
['123', '456', '789']

its no good for floating point number strings though.

SQL: Two select statements in one query

You can do something like this:

    name, games, goals
    FROM tblMadrid WHERE name = 'ronaldo')
    name, games, goals
    FROM tblBarcelona WHERE name = 'messi')
ORDER BY goals;

See, for example:

simple HTTP server in Java using only Java SE API

How about Apache Commons HttpCore project?

From the web site:... HttpCore Goals

  • Implementation of the most fundamental HTTP transport aspects
  • Balance between good performance and the clarity & expressiveness of API
  • Small (predictable) memory footprint
  • Self contained library (no external dependencies beyond JRE)

In Excel how to get the left 5 characters of each cell in a specified column and put them into a new column

1) Put =Left(E1,5) in F1

2) Copy F1, then select entire F column and paste.

Why use a READ UNCOMMITTED isolation level?

This will give you dirty reads, and show you transactions that's not committed yet. That is the most obvious answer. I don't think its a good idea to use this just to speed up your reads. There is other ways of doing that if you use a good database design.

Its also interesting to note whats not happening. READ UNCOMMITTED does not only ignore other table locks. It's also not causing any locks in its own.

Consider you are generating a large report, or you are migrating data out of your database using a large and possibly complex SELECT statement. This will cause a shared lock that's may be escalated to a shared table lock for the duration of your transaction. Other transactions may read from the table, but updates are impossible. This may be a bad idea if its a production database since the production may stop completely.

If you are using READ UNCOMMITTED you will not set a shared lock on the table. You may get the result from some new transactions or you may not depending where it the table the data were inserted and how long your SELECT transaction have read. You may also get the same data twice if for example a page split occurs (the data will be copied to another location in the data file).

So, if its very important for you that data can be inserted while doing your SELECT, READ UNCOMMITTED may make sense. You have to consider that your report may contain some errors, but if its based on millions of rows and only a few of them are updated while selecting the result this may be "good enough". Your transaction may also fail all together since the uniqueness of a row may not be guaranteed.

A better way altogether may be to use SNAPSHOT ISOLATION LEVEL but your applications may need some adjustments to use this. One example of this is if your application takes an exclusive lock on a row to prevent others from reading it and go into edit mode in the UI. SNAPSHOT ISOLATION LEVEL does also come with a considerable performance penalty (especially on disk). But you may overcome that by throwing hardware on the problem. :)

You may also consider restoring a backup of the database to use for reporting or loading data into a data warehouse.

write() versus writelines() and concatenated strings

if you just want to save and load a list try Pickle

Pickle saving:

with open("yourFile","wb")as file:

and loading:

with open("yourFile","rb")as file:

SQL Server Management Studio, how to get execution time down to milliseconds

I don't know about expanding the information bar.

But you can get the timings set as a default for all queries showing in the "Messages" tab.

When in a Query window, go to the Query Menu item, select "query options" then select "advanced" in the "Execution" group and check the "set statistics time" / "set statistics IO" check boxes. These values will then show up in the messages area for each query without having to remember to put in the set stats on and off.

You could also use Shift + Alt + S to enable client statistics at any time

Is there any 'out-of-the-box' 2D/3D plotting library for C++?

AntiGrain Geometry (AGG). Its an opensource 2D vector graphics library. Its a standalone library with no additional dependencies. Has good documentation. Python plotting library matplotlib uses AGG as one of backends.

How to echo print statements while executing a sql script

What about using mysql -v to put mysql client in verbose mode ?

Oracle JDBC intermittent Connection Issue should be right! not or

How to store .pdf files into MySQL as BLOBs using PHP?

In regards to Gordon M's answer above, the 1st and 2nd parameter in mysqli_real_escape_string () call should be swapped for the newer php versions, according to:

Is there a decorator to simply cache function return values?

I coded this simple decorator class to cache function responses. I find it VERY useful for my projects:

from datetime import datetime, timedelta 

class cached(object):
    def __init__(self, *args, **kwargs):
        self.cached_function_responses = {}
        self.default_max_age = kwargs.get("default_cache_max_age", timedelta(seconds=0))

    def __call__(self, func):
        def inner(*args, **kwargs):
            max_age = kwargs.get('max_age', self.default_max_age)
            if not max_age or func not in self.cached_function_responses or ( - self.cached_function_responses[func]['fetch_time'] > max_age):
                if 'max_age' in kwargs: del kwargs['max_age']
                res = func(*args, **kwargs)
                self.cached_function_responses[func] = {'data': res, 'fetch_time':}
            return self.cached_function_responses[func]['data']
        return inner

The usage is straightforward:

import time

def myfunc(a):
    print "in func"
    return (a,

@cached(default_max_age = timedelta(seconds=6))
def cacheable_test(a):
    print "in cacheable test: "
    return (a,

print cacheable_test(1,max_age=timedelta(seconds=5))
print cacheable_test(2,max_age=timedelta(seconds=5))
print cacheable_test(3,max_age=timedelta(seconds=5))

Auto Generate Database Diagram MySQL

Try out Vertabelo!

It's an online database modeler that supports reverse enginnering.

Just create free of charge Vertabelo account, import an existing database into Vertabelo and voila - your database is in Vertabelo!

It supports following databases:

  • PostgreSQL,
  • MySQL,
  • Oracle,
  • IBM DB2,
  • MS SQL Server.

What are unit tests, integration tests, smoke tests, and regression tests?

Unit test: Verifying that particular component (i.e., class) created or modified functions as designed. This test can be manual or automated, but it does not move beyond the boundary of the component.

Integration test: Verifying that the interaction of particular components function as designed. Integration tests can be performed at the unit level or the system level. These tests can be manual or automated.

Regression test: Verifying that new defects are not introduced into existing code. These tests can be manual or automated.

Depending upon your SDLC (waterfall, RUP, agile, etc.) particular tests may be performed in 'phases' or may all be performed, more or less, at the same time. For example, unit testing may be limited to developers who then turn the code over to testers for integration and regression testing. However, another approach might have developers doing unit testing and some level of integration and regression testing (using a TDD approach along with continuous integration and automated unit and regression tests).

The tool set will depend largely on the codebase, but there are many open source tools for unit testing (JUnit). HP's (Mercury) QTP or Borland's Silk Test are both tools for automated integration and regression testing.

How to add comments into a Xaml file in WPF?

I assume those XAML namespace declarations are in the parent tag of your control? You can't put comments inside of another tag. Other than that, the syntax you're using is correct.

<UserControl xmlns="...">
    <!-- Here's a valid comment. Notice it's outside the <UserControl> tag's braces -->

exclude @Component from @ComponentScan

The configuration seem alright, except that you should use excludeFilters instead of excludes:

@Configuration @EnableSpringConfigured
@ComponentScan(basePackages = {"com.example"}, excludeFilters={
  @ComponentScan.Filter(type=FilterType.ASSIGNABLE_TYPE, value=Foo.class)})
public class MySpringConfiguration {}

First Or Create

Previous answer is obsolete. It's possible to achieve in one step since Laravel 5.3, firstOrCreate now has second parameter values, which is being used for new record, but not for search

$user = User::firstOrCreate([
    'email' => '[email protected]'
], [
    'firstName' => 'Taylor',
    'lastName' => 'Otwell'

How to set time to a date object in java

I should like to contribute the modern answer. This involves using java.time, the modern Java date and time API, and not the old Date nor Calendar except where there’s no way to avoid it.

Your issue is very likely really a timezone issue. When it is Tue Aug 09 00:00:00 IST 2011, in time zones west of IST midnight has not yet been reached. It is still Aug 8. If for example your API for putting the date into Excel expects UTC, the date will be the day before the one you intended. I believe the real and good solution is to produce a date-time of 00:00 UTC (or whatever time zone or offset is expected and used at the other end).

    LocalDate yourDate = LocalDate.of(2018, Month.FEBRUARY, 27);
    ZonedDateTime utcDateDime = yourDate.atStartOfDay(ZoneOffset.UTC);

This prints


Z means UTC (think of it as offset zero from UTC or Zulu time zone). Better still, of course, if you could pass the LocalDate from the first code line to Excel. It doesn’t include time-of-day, so there is no confusion possible. On the other hand, if you need an old-fashioned Date object for that, convert just before handing the Date on:

    Date oldfashionedDate = Date.from(utcDateDime.toInstant());

On my computer this prints

Tue Feb 27 01:00:00 CET 2018

Don’t be fooled, it is correct. My time zone (Central European Time) is at offset +01:00 from UTC in February (standard time), so 01:00:00 here is equal to 00:00:00 UTC. It’s just Date.toString() grabbing the JVMs time zone and using it for producing the string.

How can I set it to something like 5:30 pm?

To answer your direct question directly, if you have a ZonedDateTime, OffsetDateTime or LocalDateTime, in all of these cases the following will accomplish what you asked for:

    yourDateTime = yourDateTime.with(LocalTime.of(17, 30));

If yourDateTime was a LocalDateTime of 2018-02-27T00:00, it will now be 2018-02-27T17:30. Similarly for the other types, only they include offset and time zone too as appropriate.

If you only had a date, as in the first snippet above, you can also add time-of-day information to it:

    LocalDate yourDate = LocalDate.of(2018, Month.FEBRUARY, 27);
    LocalDateTime dateTime = yourDate.atTime(LocalTime.of(17, 30));

For most purposes you should prefer to add the time-of-day in a specific time zone, though, for example

    ZonedDateTime dateTime = yourDate.atTime(LocalTime.of(17, 30))

This yields 2018-02-27T17:30+05:30[Asia/Kolkata].

Date and Calendar vs java.time

The Date class that you use as well as Calendar and SimpleDateFormat used in the other answers are long outdated, and SimpleDateFormat in particular has proven troublesome. In all cases the modern Java date and time API is so much nicer to work with. Which is why I wanted to provide this answer to an old question that is still being visited.

Link: Oracle Tutorial Date Time, explaining how to use java.time.

What are and

DEVELOPER runs autoconf and automake:

  1. autoconf -- creates shippable configure script
    (which the installer will later run to make the Makefile)
  1. automake - creates shippable data file
    (which configure will later read to make the Makefile)

INSTALLER runs configure, make and sudo make install:

./configure       # Creates  Makefile        (from  
make              # Creates  the application (from the Makefile just created).  

sudo make install # Installs the application 
                  #   Often, by default its files are installed into /usr/local


Notation below is roughly: inputs --> programs --> outputs

DEVELOPER runs these: -> autoconf -> configure (script) --- (*.ac = autoconf) --> autoconf -> configure (script) --- ( depreciated. Use -> automake -> ----------- (*.am = automake)

INSTALLER runs these: -> configure -> Makefile (*.in = input file)

Makefile -> make ----------> (puts new software in your downloads or temporary directory)
Makefile -> make install -> (puts new software in system directories)

"autoconf is an extensible package of M4 macros that produce shell scripts to automatically configure software source code packages. These scripts can adapt the packages to many kinds of UNIX-like systems without manual user intervention. Autoconf creates a configuration script for a package from a template file that lists the operating system features that the package can use, in the form of M4 macro calls."

"automake is a tool for automatically generating files compliant with the GNU Coding Standards. Automake requires the use of Autoconf."


Free online tutorials:


The main used to build LibreOffice is over 12k lines of code, (but there are also 57 other files in subfolders.)

From this my generated configure is over 41k lines of code.

And while the and Makefile are both only 493 lines of code. (But, there are also 768 more's in subfolders.)

How to programmatically move, copy and delete files and directories on SD?

Use standard Java I/O. Use Environment.getExternalStorageDirectory() to get to the root of external storage (which, on some devices, is an SD card).

Creating a class object in c++

First of all, both cases calls a constructor. If you write

Example *example = new Example();

then you are creating an object, call the constructor and retrieve a pointer to it.

If you write

Example example;

The only difference is that you are getting the object and not a pointer to it. The constructor called in this case is the same as above, the default (no argument) constructor.

As for the singleton question, you must simple invoke your static method by writing:

Example *e = Singleton::getExample();

What is the OAuth 2.0 Bearer Token exactly?

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

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

Duplicate / Copy records in the same MySQL table

I needed this as well; my solution was to use SQLYOG (free version) to export the desired record as SQL (creates an insert).

I then hand edited this to remove the id as this needs to be auto-generated and then copied the insert into SQLYog to execute it. This was painless. I guess plenty of other MySQL GUIs can do this as well.

This provides me with a record I can use for test purposes on a live system.

I now have this insert for reuse as well, as the table is rewritten daily.

How to know a Pod's own IP address from inside a container in the Pod?

The simplest answer is to ensure that your pod or replication controller yaml/json files add the pod IP as an environment variable by adding the config block defined below. (the block below additionally makes the name and namespace available to the pod)

- name: MY_POD_NAME
      fieldPath: metadata.namespace
- name: MY_POD_IP
      fieldPath: status.podIP

Recreate the pod/rc and then try

echo $MY_POD_IP

also run env to see what else kubernetes provides you with.


How to enter newline character in Oracle?

   dbms_output.put_line( 'hello' ||chr(13) || chr(10) || 'world' );

How to create a link to another PHP page


<a href="page2.php">Link</a>

And if you need to pass a value:

<a href="page2.php?val=1">Link that pass the value 1</a>

To retrive the value put in page2.php this code:

$val = $_GET["val"];

Now the variable $val has the value 1.

How to open a new tab using Selenium WebDriver

Just for anyone else who's looking for an answer in Ruby, Python, and C# bindings (Selenium 2.33.0).

Note that the actual keys to send depend on your OS. For example, Mac uses CMD + T, instead of Ctrl + T.


require 'selenium-webdriver'

driver = Selenium::WebDriver.for :firefox

body = driver.find_element(:tag_name => 'body')
body.send_keys(:control, 't')



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

driver = webdriver.Firefox()

body = driver.find_element_by_tag_name("body")
body.send_keys(Keys.CONTROL + 't')



using OpenQA.Selenium;
using OpenQA.Selenium.Firefox;

namespace StackOverflowTests {

    class OpenNewTab {

        static void Main(string[] args) {

            IWebDriver driver = new FirefoxDriver();

            IWebElement body = driver.FindElement(By.TagName("body"));
            body.SendKeys(Keys.Control + 't');


What is more efficient? Using pow to square or just multiply it with itself?

The most efficient way is to consider the exponential growth of the multiplications. Check this code for p^q:

template <typename T>
T expt(T p, unsigned q){
    T r =1;
    while (q != 0) {
        if (q % 2 == 1) {    // if q is odd
            r *= p;
        p *= p;
        q /= 2;
    return r;

how to pass this element to javascript onclick function and add a class to that clicked element

Use this html to get the clicked element:

<div class="row" style="padding-left:21px;">
    <ul class="nav nav-tabs" style="padding-left:40px;">
        <li class="active filter"><a href="#month" onclick="Data('month', this)">This Month</a></li>
        <li class="filter"><a href="#year" onclick="Data('year', this)">Year</a></li>
        <li class="filter"><a href="#last60" onclick="Data('last60', this)">60 Days</a></li>
        <li class="filter"><a href="#last90" onclick="Data('last90', this)">90 Days</a></li>


 function Data(string, el)

How to select current date in Hive SQL

According to the LanguageManual, you can use unix_timestamp() to get the "current time stamp using the default time zone." If you need to convert that to something more human-readable, you can use from_unixtime(unix_timestamp()).

Hope that helps.

How to use requirements.txt to install all dependencies in a python project

(Taken from my comment)

pip won't handle system level dependencies. You'll have to apt-get install libfreetype6-dev before continuing. (It even says so right in your output. Try skimming over it for such errors next time, usually build outputs are very detailed)

How to get values of selected items in CheckBoxList with foreach in ASP.NET C#?

I like to use this simple method to get the selected values and join them into a string

private string JoinCBLSelectedValues(CheckBoxList cbl, string separator = "")
    return string.Join(separator, cbl.Items.Cast<ListItem>().Where(li => li.Selected).ToList());

How to make a text box have rounded corners?

You could use CSS to do that, but it wouldn't be supported in IE8-. You can use some site like to come up with actual CSS you'd use, which would look something like this (again, depending on how many browsers you're trying to support):

-webkit-border-radius: 5px;
-moz-border-radius: 5px;
border-radius: 5px;

Maven: Command to update repository after adding dependency to POM

mvn install (or mvn package) will always work.

You can use mvn compile to download compile time dependencies or mvn test for compile time and test dependencies but I prefer something that always works.

Java - JPA - @Version annotation

Although @Pascal answer is perfectly valid, from my experience I find the code below helpful to accomplish optimistic locking:

public class MyEntity implements Serializable {    
    // ...

    @Column(name = "optlock", columnDefinition = "integer DEFAULT 0", nullable = false)
    private long version = 0L;

    // ...

Why? Because:

  1. Optimistic locking won't work if field annotated with @Version is accidentally set to null.
  2. As this special field isn't necessarily a business version of the object, to avoid a misleading, I prefer to name such field to something like optlock rather than version.

First point doesn't matter if application uses only JPA for inserting data into the database, as JPA vendor will enforce 0 for @version field at creation time. But almost always plain SQL statements are also in use (at least during unit and integration testing).

CSS: How to have position:absolute div inside a position:relative div not be cropped by an overflow:hidden on a container

I don't really see a way to do this as-is. I think you might need to remove the overflow:hidden from div#1 and add another div within div#1 (ie as a sibling to div#2) to hold your unspecified 'content' and add the overflow:hidden to that instead. I don't think that overflow can be (or should be able to be) over-ridden.

How to check if element exists using a lambda expression?

The above answers require you to malloc a new stream object.

public <T>
boolean containsByLambda(Collection<? extends T> c, Predicate<? super T> p) {

    for (final T z : c) {
        if (p.test(z)) {
            return true;
    return false;

public boolean containsTabById(TabPane tabPane, String id) {
    return containsByLambda(tabPane.getTabs(), z -> z.getId().equals(id));
if (containsTabById(tabPane, idToCheck))) {

How do I fetch multiple columns for use in a cursor loop?

Here is slightly modified version. Changes are noted as code commentary.


declare @cnt int
declare @test nvarchar(128)
-- variable to hold table name
declare @tableName nvarchar(255)
declare @cmd nvarchar(500) 
-- local means the cursor name is private to this code
-- fast_forward enables some speed optimizations
declare Tests cursor local fast_forward for

open Tests
-- Instead of fetching twice, I rather set up no-exit loop
while 1 = 1
  -- And then fetch
  fetch next from Tests into @test, @tableName
  -- And then, if no row is fetched, exit the loop
  if @@fetch_status <> 0
  -- Quotename is needed if you ever use special characters
  -- in table/column names. Spaces, reserved words etc.
  -- Other changes add apostrophes at right places.
  set @cmd = N'exec sp_rename ''' 
           + quotename(@tableName) 
           + '.' 
           + quotename(@test) 
           + N''',''' 
           + RIGHT(@test,LEN(@test)-3) 
           + '_Pct''' 
           + N', ''column''' 

  print @cmd

  EXEC sp_executeSQL @cmd

close Tests 
deallocate Tests


How to use sed to remove all double quotes within a file

Try prepending the doublequote with a backslash in your expresssion:

sed 's/\"//g' [file name]

Find all elements on a page whose element ID contains a certain text using jQuery

$('*[id*=mytext]:visible').each(function() {

Note the asterisk '*' at the beginning of the selector matches all elements.

See the Attribute Contains Selectors, as well as the :visible and :hidden selectors.

How do I force a vertical scrollbar to appear?

html { overflow-y: scroll; }

This css rule causes a vertical scrollbar to always appear.


ASP.NET postback with JavaScript

If anyone's having trouble with this (as I was), you can get the postback code for a button by adding the UseSubmitBehavior="false" attribute to it. If you examine the rendered source of the button, you'll see the exact javascript you need to execute. In my case it was using the name of the button rather than the id.

Is optimisation level -O3 dangerous in g++?

In my somewhat checkered experience, applying -O3 to an entire program almost always makes it slower (relative to -O2), because it turns on aggressive loop unrolling and inlining that make the program no longer fit in the instruction cache. For larger programs, this can also be true for -O2 relative to -Os!

The intended use pattern for -O3 is, after profiling your program, you manually apply it to a small handful of files containing critical inner loops that actually benefit from these aggressive space-for-speed tradeoffs. Newer versions of GCC have a profile-guided optimization mode that can (IIUC) selectively apply the -O3 optimizations to hot functions -- effectively automating this process.

XSL xsl:template match="/"

It's worth noting, since it's confusing for people new to XML, that the root (or document node) of an XML document is not the top-level element. It's the parent of the top-level element. This is confusing because it doesn't seem like the top-level element can have a parent. Isn't it the top level?

But look at this, a well-formed XML document:

<?xml-stylesheet href="my_transform.xsl" type="text/xsl"?>
<!-- Comments and processing instructions are XML nodes too, remember. -->

The root of this document has three children: a processing instruction, a comment, and an element.

So, for example, if you wanted to write a transform that got rid of that comment, but left in any comments appearing anywhere else in the document, you'd add this to the identity transform:

<xsl:template match="/comment()"/>

Even simpler (and more commonly useful), here's an XPath pattern that matches the document's top-level element irrespective of its name: /*.

What is the 'override' keyword in C++ used for?

And as an addendum to all answers, FYI: override is not a keyword, but a special kind of identifier! It has meaning only in the context of declaring/defining virtual functions, in other contexts it's just an ordinary identifier. For details read 2.11.2 of The Standard.

#include <iostream>

struct base
    virtual void foo() = 0;

struct derived : base
    virtual void foo() override
        std::cout << __PRETTY_FUNCTION__ << std::endl;

int main()
    base* override = new derived();
    return 0;


zaufi@gentop /work/tests $ g++ -std=c++11 -o override-test
zaufi@gentop /work/tests $ ./override-test
virtual void derived::foo()

How to stop tracking and ignore changes to a file in Git?

The accepted answer still did not work for me

I used

git rm -r --cached .

git add .

git commit -m "fixing .gitignore"

Found the answer from here

Does the join order matter in SQL?

If you try joining C on a field from B before joining B, i.e.:

       on B.x = C.x
       on A.x = B.x

your query will fail, so in this case the order matters. Access denied (

Within your <jre location>\lib\security\java.policy try adding:

grant { permission; };

And see if it allows you. If so, you will have to add more granular permissions.


Java 8 Documentation for java.policy files


How do I handle newlines in JSON?

I used this function to strip newline or other characters in data to parse JSON data:

function normalize_str($str) {

    $invalid = array(
        'Š'=>'S', 'š'=>'s',  'Ð'=>'Dj', 'd'=>'dj', 'Ž'=>'Z', 'ž'=>'z',
        'C'=>'C', 'c'=>'c',  'C'=>'C',  'c'=>'c',  'À'=>'A', 'Á'=>'A', 'Â'=>'A', 'Ã'=>'A',
        'Ä'=>'A', 'Å'=>'A',  'Æ'=>'A',  'Ç'=>'C',  'È'=>'E', 'É'=>'E', 'Ê'=>'E', 'Ë'=>'E',
        'Ì'=>'I', 'Í'=>'I',  'Î'=>'I',  'Ï'=>'I',  'Ñ'=>'N', 'Ò'=>'O', 'Ó'=>'O', 'Ô'=>'O',
        'Õ'=>'O', 'Ö'=>'O',  'Ø'=>'O',  'Ù'=>'U',  'Ú'=>'U', 'Û'=>'U', 'Ü'=>'U', 'Ý'=>'Y',
        'Þ'=>'B', 'ß'=>'Ss', 'à'=>'a',  'á'=>'a',  'â'=>'a', 'ã'=>'a', 'ä'=>'a', 'å'=>'a',
        'æ'=>'a', 'ç'=>'c',  'è'=>'e',  'é'=>'e',  'ê'=>'e', 'ë'=>'e', 'ì'=>'i', 'í'=>'i',
        'î'=>'i', 'ï'=>'i',  'ð'=>'o',  'ñ'=>'n',  'ò'=>'o', 'ó'=>'o', 'ô'=>'o', 'õ'=>'o',
        'ö'=>'o', 'ø'=>'o',  'ù'=>'u',  'ú'=>'u',  'û'=>'u', 'ý'=>'y', 'ý'=>'y', 'þ'=>'b',
        'ÿ'=>'y', 'R'=>'R',  'r'=>'r',
        "`" => "'", "´" => "'",  '"' => ',',  '`' => "'",
        '´' => "'", '"' => '\"', '"' => "\"", '´' => "'",
        "&acirc;€™" => "'",
        "{" => "",
        "~" => "",  "–" => "-",  "'" => "'",  "     " => " ");

    $str = str_replace(array_keys($invalid), array_values($invalid), $str);

    $remove = array("\n", "\r\n", "\r");
    $str = str_replace($remove, "\\n", trim($str));

    //$str = htmlentities($str, ENT_QUOTES);

    return htmlspecialchars($str);

echo normalize_str($lst['address']);

What is the Difference Between read() and recv() , and Between send() and write()?

On Linux I also notice that :

Interruption of system calls and library functions by signal handlers
If a signal handler is invoked while a system call or library function call is blocked, then either:

  • the call is automatically restarted after the signal handler returns; or

  • the call fails with the error EINTR.

... The details vary across UNIX systems; below, the details for Linux.

If a blocked call to one of the following interfaces is interrupted by a signal handler, then the call is automatically restarted after the signal handler returns if the SA_RESTART flag was used; otherwise the call fails with the error EINTR:

  • read(2), readv(2), write(2), writev(2), and ioctl(2) calls on "slow" devices.


The following interfaces are never restarted after being interrupted by a signal handler, regardless of the use of SA_RESTART; they always fail with the error EINTR when interrupted by a signal handler:

  • "Input" socket interfaces, when a timeout (SO_RCVTIMEO) has been set on the socket using setsockopt(2): accept(2), recv(2), recvfrom(2), recvmmsg(2) (also with a non-NULL timeout argument), and recvmsg(2).

  • "Output" socket interfaces, when a timeout (SO_RCVTIMEO) has been set on the socket using setsockopt(2): connect(2), send(2), sendto(2), and sendmsg(2).

Check man 7 signal for more details.

A simple usage would be use signal to avoid recvfrom blocking indefinitely.

An example from APUE:

#include "apue.h"
#include <netdb.h>
#include <errno.h>
#include <sys/socket.h>

#define BUFLEN      128
#define TIMEOUT     20

sigalrm(int signo)

print_uptime(int sockfd, struct addrinfo *aip)
    int     n;
    char    buf[BUFLEN];

    buf[0] = 0;
    if (sendto(sockfd, buf, 1, 0, aip->ai_addr, aip->ai_addrlen) < 0)
        err_sys("sendto error");
    if ((n = recvfrom(sockfd, buf, BUFLEN, 0, NULL, NULL)) < 0) {
        if (errno != EINTR)
        err_sys("recv error");
    write(STDOUT_FILENO, buf, n);

main(int argc, char *argv[])
    struct addrinfo     *ailist, *aip;
    struct addrinfo     hint;
    int                 sockfd, err;
    struct sigaction    sa;

    if (argc != 2)
        err_quit("usage: ruptime hostname");
    sa.sa_handler = sigalrm;
    sa.sa_flags = 0;
    if (sigaction(SIGALRM, &sa, NULL) < 0)
        err_sys("sigaction error");
    memset(&hint, 0, sizeof(hint));
    hint.ai_socktype = SOCK_DGRAM;
    hint.ai_canonname = NULL;
    hint.ai_addr = NULL;
    hint.ai_next = NULL;
    if ((err = getaddrinfo(argv[1], "ruptime", &hint, &ailist)) != 0)
        err_quit("getaddrinfo error: %s", gai_strerror(err));

    for (aip = ailist; aip != NULL; aip = aip->ai_next) {
        if ((sockfd = socket(aip->ai_family, SOCK_DGRAM, 0)) < 0) {
            err = errno;
        } else {
            print_uptime(sockfd, aip);

    fprintf(stderr, "can't contact %s: %s\n", argv[1], strerror(err));

How do I set path while saving a cookie value in JavaScript?

See for more documentation:

 setItem: function (sKey, sValue, vEnd, sPath, sDomain, bSecure) {  
     if (!sKey || /^(?:expires|max\-age|path|domain|secure)$/.test(sKey)) { return; }  
     var sExpires = "";  
     if (vEnd) {  
       switch (typeof vEnd) {  
         case "number": sExpires = "; max-age=" + vEnd; break;  
         case "string": sExpires = "; expires=" + vEnd; break;  
         case "object": if (vEnd.hasOwnProperty("toGMTString")) { sExpires = "; expires=" + vEnd.toGMTString(); } break;  
     document.cookie = escape(sKey) + "=" + escape(sValue) + sExpires + (sDomain ? "; domain=" + sDomain : "") + (sPath ? "; path=" + sPath : "") + (bSecure ? "; secure" : "");  

How to check if my string is equal to null?

This should work:

if (myString != null && !myString.equals(""))

If not, then myString likely has a value that you are not expecting. Try printing it out like this:

System.out.println("+" + myString + "+");

Using the '+' symbols to surround the string will show you if there is extra whitespace in there that you're not accounting for.

How to link HTML5 form action to Controller ActionResult method in ASP.NET MVC 4

Here I'm basically wrapping a button in a link. The advantage is that you can post to different action methods in the same form.

<a href="Controller/ActionMethod">
    <input type="button" value="Click Me" />

Adding parameters:

<a href="Controller/ActionMethod?userName=ted">
    <input type="button" value="Click Me" />

Adding parameters from a non-enumerated Model:

<a href="Controller/[email protected]">
    <input type="button" value="Click Me" />

You can do the same for an enumerated Model too. You would just have to reference a single entity first. Happy Coding!

C - function inside struct

This will only work in C++. Functions in structs are not a feature of C.

Same goes for your client.AddClient(); call ... this is a call for a member function, which is object oriented programming, i.e. C++.

Convert your source to a .cpp file and make sure you are compiling accordingly.

If you need to stick to C, the code below is (sort of) the equivalent:

typedef struct client_t client_t, *pno;
struct client_t
        pid_t pid;
        char password[TAM_MAX]; // -> 50 chars
        pno next;


pno AddClient(pno *pclient) 
    /* code */

int main()

    client_t client;

    //code ..



Flutter : Vertically center column



How can I unstage my files again after making a local commit?

git reset --soft HEAD~1 should do what you want. After this, you'll have the first changes in the index (visible with git diff --cached), and your newest changes not staged. git status will then look like this:

# On branch master
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#       modified:
# Changes not staged for commit:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#       modified:

You can then do git add and commit both changes at once.

symbol(s) not found for architecture i386

I've been stumped by this one before only to realize I added a data-only @interface and forgot to add the empty @implementation block.

Error sending json in POST to web API service

In the HTTP request you need to set Content-Type to: Content-Type: application/json

So if you're using fiddler client add Content-Type: application/json to the request header

How do I save a String to a text file using Java?

If you only care about pushing one block of text to file, this will overwrite it each time.

JFileChooser chooser = new JFileChooser();
int returnVal = chooser.showSaveDialog(this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
    FileOutputStream stream = null;
    PrintStream out = null;
    try {
        File file = chooser.getSelectedFile();
        stream = new FileOutputStream(file); 
        String text = "Your String goes here";
        out = new PrintStream(stream);
        out.print(text);                  //This will overwrite existing contents

    } catch (Exception ex) {
        //do something
    } finally {
        try {
            if(stream!=null) stream.close();
            if(out!=null) out.close();
        } catch (Exception ex) {
            //do something

This example allows the user to select a file using a file chooser.

Add a pipe separator after items in an unordered list unless that item is the last on a line


li + li::before {
    content: " | ";

Of course, this does not actually solve the OP's problem. He wants to elide the vertical bars at the beginning and end of lines depending on where they are broken. I will go out on a limb and assert that this problem is not solvable using CSS, and not even with JS unless one wants to essentially rewrite the browser engine's text-measurement/layout/line breaking logic.

The only pieces of CSS, as far as I can see, that "know" about line breaking are, first, the ::first-line pseudo element, which does not help us here--in any case, it is limited to a few presentational attributes, and does not work together with things like ::before and ::after. The only other aspect of CSS I can think of that to some extent exposes line-breaking is hyphenation. However, hyphenating is all about adding a character (usually a dash) to the end of lines in certain situations, whereas here we are concerned about removing a character (the vertical line), so I just can't see how to apply any kind of hyphenation-related logic, even with the help of properties such as hyphenate-character.

We have the word-spacing property, which is applied intra-line but not at line beginnings and endings, which seems promising, but it defines the width of the space between words, not the character(s) to be used.

One wonders if there's some way to use the text-overflow property, which has the little-known ability to take two values for display of overflow text at both left and right, as in

text-overflow: '' '';

but there still doesn't seem to be any obvious way to get from A to B here.

How to display a "busy" indicator with jQuery?

You can just show / hide a gif, but you can also embed that to ajaxSetup, so it's called on every ajax request.

        // show gif here, eg:
        // hide gif here, eg:

One note is that if you want to do an specific ajax request without having the loading spinner, you can do it like this:

   global: false,
   // stuff

That way the previous $.ajaxSetup we did will not affect the request with global: false.

More details available at:

Binding a generic list to a repeater - ASP.NET

You may want to create a subRepeater.

<asp:Repeater ID="SubRepeater" runat="server" DataSource='<%# Eval("Fields") %>'>
    <span><%# Eval("Name") %></span>

You can also cast your fields

<%# ((ArrayFields)Container.DataItem).Fields[0].Name %>

Finally you could do a little CSV Function and write out your fields with a function

<%# GetAsCsv(((ArrayFields)Container.DataItem).Fields) %>

public string GetAsCsv(IEnumerable<Fields> fields)
  var builder = new StringBuilder();
  foreach(var f in fields)
  builder.Remove(builder.Length - 1);
  return builder.ToString();

Artificially create a connection timeout error

Plenty of good answers but the cleanest solution seems to be this service

You can configure the timeout duration (up to 230 seconds) and eventual return code.

Execution Failed for task :app:compileDebugJavaWithJavac in Android Studio

The problem is just in naming folder, if your folder to save your project contains special characters then remove them. If the error persists try to save the folder with no space.

Find rows that have the same value on a column in MySQL

First part of accepted answer does not work for MSSQL.
This worked for me:

select email, COUNT(*) as C from table 
group by email having COUNT(*) >1 order by C desc

How to get first/top row of the table in Sqlite via Sql Query

LIMIT 1 is what you want. Just keep in mind this returns the first record in the result set regardless of order (unless you specify an order clause in an outer query).