Programs & Examples On #Trust

Trust is a measure of how much an entity relies on other entities for its security.

Could not establish trust relationship for SSL/TLS secure channel -- SOAP

The very simple "catch all" solution is this:

System.Net.ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };

The solution from sebastian-castaldi is a bit more detailed.

Is there a cross-browser onload event when clicking the back button?

I couldn't get the above examples to work. I simply wanted to trigger a refresh of certain modified div areas when coming back to the page via the back button. The trick I used was to set a hidden input field (called a "dirty bit") to 1 as soon as the div areas changed from the original. The hidden input field actually retains its value when I click back, so onload I can check for this bit. If it's set, I refresh the page (or just refresh the divs). On the original load, however, the bit is not set, so I don't waste time loading the page twice.

<input type='hidden' id='dirty'>

$(document).ready(function() {
  if ($('#dirty').val()) {
    // ... reload the page or specific divs only
  // when something modifies a div that needs to be refreshed, set dirty=1

And it would trigger properly whenever I clicked the back button.

Serialize object to query string in JavaScript/jQuery

Alternatively YUI has

For example:

var data = { one: 'first', two: 'second' };
var result = Y.QueryString.stringify(data);

Explicitly select items from a list or tuple

>>> map(myList.__getitem__, (2,2,1,3))
('baz', 'baz', 'bar', 'quux')

You can also create your own List class which supports tuples as arguments to __getitem__ if you want to be able to do myList[(2,2,1,3)].

Short form for Java if statement

name = ( (city.getName() == null)? "N/A" : city.getName() );

firstly the condition (city.getName() == null) is checked. If yes, then "N/A" is assigned to name or simply name="N/A" or else the value from city.getName() is assigned to name, i.e. name=city.getName().

Things to look out here:

  1. condition is in the parenthesis followed by a question mark. That's why I write (city.getName() == null)?. Here the question mark is right after the condition. Easy to see/read/guess even!
  2. value left of colon (:) and value right of colon (a) value left of colon is assigned when condition is true, else the value right of colon is assigned to the variable.

here's a reference:

C# cannot convert method to non delegate type

You need to add parentheses after a method call, else the compiler will think you're talking about the method itself (a delegate type), whereas you're actually talking about the return value of that method.

string t = obj.getTitle();

Extra Non-Essential Information

Also, have a look at properties. That way you could use title as if it were a variable, while, internally, it works like a function. That way you don't have to write the functions getTitle() and setTitle(string value), but you could do it like this:

public string Title // Note: public fields, methods and properties use PascalCasing
    get // This replaces your getTitle method
        return _title; // Where _title is a field somewhere
    set // And this replaces your setTitle method
        _title = value; // value behaves like a method parameter

Or you could use auto-implemented properties, which would use this by default:

public string Title { get; set; }

And you wouldn't have to create your own backing field (_title), the compiler would create it itself.

Also, you can change access levels for property accessors (getters and setters):

public string Title { get; private set; }

You use properties as if they were fields, i.e.:

this.Title = "Example";
string local = this.Title;

CSS transition fade in

CSS Keyframes support is pretty good these days:

.fade-in {_x000D_
 opacity: 1;_x000D_
 animation-name: fadeInOpacity;_x000D_
 animation-iteration-count: 1;_x000D_
 animation-timing-function: ease-in;_x000D_
 animation-duration: 2s;_x000D_
@keyframes fadeInOpacity {_x000D_
 0% {_x000D_
  opacity: 0;_x000D_
 100% {_x000D_
  opacity: 1;_x000D_
<h1 class="fade-in">Fade Me Down Scotty</h1>

Java synchronized method lock on object, or method?

In java synchronization,if a thread want to enter into synchronization method it will acquire lock on all synchronized methods of that object not just on one synchronized method that thread is using. So a thread executing addA() will acquire lock on addA() and addB() as both are synchronized.So other threads with same object cannot execute addB().

Oracle date to string conversion

Try this. Oracle has this feature to distinguish the millennium years..

As you mentioned, if your column is a varchar, then the below query will yield you 1989..

select to_date(column_name,'dd/mm/rr') from table1;

When the format rr is used in year, the following would be done by oracle.

if rr->00 to 49 ---> result will be 2000 - 2049, if rr->50 to 99 ---> result will be 1950 - 1999

jquery data selector

If you also use jQueryUI, you get a (simple) version of the :data selector with it that checks for the presence of a data item, so you can do something like $("div:data(view)"), or $( this ).closest(":data(view)").

See . I don't know for how long they've had it, but it's there now!

Rotating x axis labels in R for barplot

use optional parameter las=2 .

barplot(mytable,main="Car makes",ylab="Freqency",xlab="make",las=2)

enter image description here

How to use regex in XPath "contains" function

If you're using Selenium with Firefox you should be able to use EXSLT extensions, and regexp:test()

Does this work for you?

String expr = "//*[regexp:test(@id, 'sometext[0-9]+_text')]";

Observable Finally on Subscribe

The current "pipable" variant of this operator is called finalize() (since RxJS 6). The older and now deprecated "patch" operator was called finally() (until RxJS 5.5).

I think finalize() operator is actually correct. You say:

do that logic only when I subscribe, and after the stream has ended

which is not a problem I think. You can have a single source and use finalize() before subscribing to it if you want. This way you're not required to always use finalize():

let source = new Observable(observer => {;
  observer.error('error message');;

  finalize(() => console.log('Finally callback')),
  value => console.log('#1 Next:', value),
  error => console.log('#1 Error:', error),
  () => console.log('#1 Complete')

  value => console.log('#2 Next:', value),
  error => console.log('#2 Error:', error),
  () => console.log('#2 Complete')


This prints to console:

#1 Next: 1
#2 Next: 1
#1 Error: error message
Finally callback
#2 Error: error message

Jan 2019: Updated for RxJS 6

Tomcat is web server or application server?

It runs Java compiled code, it can maintain database connection pools, it can log errors of various types. I'd call it an application server, in fact I do. In our environment we have Apache as the webserver fronting a number of different application servers, including Tomcat and Coldfusion, and others.

sqlite database default time value 'now'

according to dr. hipp in a recent list post:

CREATE TABLE whatever(
     timestamp DATE DEFAULT (datetime('now','localtime')),

SqlException from Entity Framework - New transaction is not allowed because there are other threads running in the session

I was also facing same issue.

Here is the cause and solution.

Make sure before firing data manipulation commands like inserts, updates, you have closed all previous active SQL readers.

Most common error is functions that read data from db and return values. For e.g functions like isRecordExist.

In this case we immediately return from the function if we found the record and forget to close the reader.

How to set upload_max_filesize in .htaccess?

php_value memory_limit 30M
php_value post_max_size 100M
php_value upload_max_filesize 30M

Use all 3 in .htaccess after everything at last line. php_value post_max_size must be more than than the remaining two.

How to force Docker for a clean build of an image

GUI-driven approach: Open the docker desktop tool (that usually comes with Docker):

  1. under "Containers / Apps" stop all running instances of that image
  2. under "Images" remove the build image (hover over the box name to get a context menu), eventually also the underlying base image

How to pass parameters or arguments into a gradle task

If the task you want to pass parameters to is of type JavaExec and you are using Gradle 5, for example the application plugin's run task, then you can pass your parameters through the --args=... command line option. For example gradle run --args="foo --bar=true".

Otherwise there is no convenient builtin way to do this, but there are 3 workarounds.

1. If few values, task creation function

If the possible values are few and are known in advance, you can programmatically create a task for each of them:

void createTask(String platform) {
   String taskName = "myTask_" + platform;
   task (taskName) {
      ... do what you want

String[] platforms = ["macosx", "linux32", "linux64"];
for(String platform : platforms) {

You would then call your tasks the following way:

./gradlew myTask_macosx

2. Standard input hack

A convenient hack is to pass the arguments through standard input, and have your task read from it:

./gradlew myTask <<<"arg1 arg2 arg\ in\ several\ parts"

with code below:

String[] splitIntoTokens(String commandLine) {
    String regex = "(([\"']).*?\\2|(?:[^\\\\ ]+\\\\\\s+)+[^\\\\ ]+|\\S+)";
    Matcher matcher = Pattern.compile(regex).matcher(commandLine);
    ArrayList<String> result = new ArrayList<>();
    while (matcher.find()) {
    return result.toArray();   

task taskName, {
        doFirst {
            String typed = new Scanner(;
            String[] parsed = splitIntoTokens(typed);
            println ("Arguments received: " + parsed.join(" "))
            ... do what you want

You will also need to add the following lines at the top of your build script:

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.Scanner;

3. -P parameters

The last option is to pass a -P parameter to Gradle:

./gradlew myTask -PmyArg=hello

You can then access it as myArg in your build script:

task myTask {
    doFirst {
       println myArg
       ... do what you want

Credit to @789 for his answer on splitting arguments into tokens

Converting a vector<int> to string

template<typename T>
string str(T begin, T end)
    stringstream ss;
    bool first = true;
    for (; begin != end; begin++)
        if (!first)
            ss << ", ";
        ss << *begin;
        first = false;
    return ss.str();

This is the str function that can make integers turn into a string and not into a char for what the integer represents. Also works for doubles.

How do I solve this error, "error while trying to deserialize parameter"

I have a solution for this but not sure on the reason why this would be different from one environment to the other - although one big difference between the two environments is WSS svc pack 1 was installed on the environment where the error was occurring.

To fix this issue I got a good clue from this link - ie to "please check the Xml Schema of your service" and "the sequence in the schema is sorted alphabetically"

Looking at the wsdl generated I noticed that for the serialized class that was causing the error, the properties of this class were not visible in the wsdl.

The Definition of the class had private setters for most of the properties, but not for CustomFields property ie..

public class FileMetaDataDto
    . a constructor...   etc and several other properties edited for brevity

    public int Id { get; private set; }
    public string Version { get; private set; }
    public List<MetaDataValueDto> CustomFields { get; set; }


On removing private from the setter and redeploying the service then looking at the wsdl again, these properties were now visible, and the original error was fixed.

So the wsdl before update was

- <s:complexType name="ArrayOfFileMetaDataDto">
- <s:sequence>
  <s:element minOccurs="0" maxOccurs="unbounded" name="FileMetaDataDto" nillable="true" type="tns:FileMetaDataDto" /> 
- <s:complexType name="FileMetaDataDto">
- <s:sequence>
  <s:element minOccurs="0" maxOccurs="1" name="CustomFields" type="tns:ArrayOfMetaDataValueDto" /> 

The wsdl after update was

- <s:complexType name="ArrayOfFileMetaDataDto">
- <s:sequence>
  <s:element minOccurs="0" maxOccurs="unbounded" name="FileMetaDataDto" nillable="true" type="tns:FileMetaDataDto" /> 
- <s:complexType name="FileMetaDataDto">
- <s:sequence>
  <s:element minOccurs="1" maxOccurs="1" name="Id" type="s:int" /> 
  <s:element minOccurs="0" maxOccurs="1" name="Name" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="Title" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="ContentType" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="Icon" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="ModifiedBy" type="s:string" /> 
  <s:element minOccurs="1" maxOccurs="1" name="ModifiedDateTime" type="s:dateTime" /> 
  <s:element minOccurs="1" maxOccurs="1" name="FileSizeBytes" type="s:int" /> 
  <s:element minOccurs="0" maxOccurs="1" name="Url" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="RelativeFolderPath" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="DisplayVersion" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="Version" type="s:string" /> 
  <s:element minOccurs="0" maxOccurs="1" name="CustomFields" type="tns:ArrayOfMetaDataValueDto" /> 
  <s:element minOccurs="0" maxOccurs="1" name="CheckoutBy" type="s:string" /> 

Android Webview - Completely Clear the Cache


How to create a new schema/new user in Oracle Database 11g?

From oracle Sql developer, execute the below in sql worksheet:

create user lctest identified by lctest;
grant dba to lctest;

then right click on "Oracle connection" -> new connection, then make everything lctest from connection name to user name password. Test connection shall pass. Then after connected you will see the schema.

how to take user input in Array using java?

int length;
    Scanner input = new Scanner(;
    System.out.println("How many numbers you wanna enter?");
    length = input.nextInt();
    System.out.println("Enter " + length + " numbers, one by one...");
    int[] arr = new int[length];
    for (int i = 0; i < arr.length; i++) {
        System.out.println("Enter the number " + (i + 1) + ": ");
        //Below is the way to collect the element from the user
        arr[i] = input.nextInt();

        // auto generate the elements
        //arr[i] = (int)(Math.random()*100);

How to set 00:00:00 using moment.js

Moment.js stores dates it utc and can apply different timezones to it. By default it applies your local timezone. If you want to set time on utc date time you need to specify utc timezone.

Try the following code:

var m = moment().utcOffset(0);

What Language is Used To Develop Using Unity

i remember this from reading some articles about performance in unity from internet which awaring javascript users from using it in unity about really massive issues of using javascript in unity instead of C#, it says that C# is almost 4x faster than javascript!
i really appreciate that article b/c it saved my ass when i was about to start gaming, i dont mean that javascript it bad for unity developers , it is good but my advice could be that if you like using javascript, you should use it for simple small gamesNOT FOR BIG PROJECTS because it really can be a damn problem!

How to extract the nth word and count word occurrences in a MySQL string?

No, there isn't a syntax for extracting text using regular expressions. You have to use the ordinary string manipulation functions.

Alternatively select the entire value from the database (or the first n characters if you are worried about too much data transfer) and then use a regular expression on the client.

Inserting a text where cursor is using Javascript/jquery

Adding text to current cursor position involves two steps:

  1. Adding the text at the current cursor position
  2. Updating the current cursor position


Tested in Chrome 48, Firefox 45, IE 11 and Edge 25


function addTextAtCaret(textAreaId, text) {
    var textArea = document.getElementById(textAreaId);
    var cursorPosition = textArea.selectionStart;
    addTextAtCursorPosition(textArea, cursorPosition, text);
    updateCursorPosition(cursorPosition, text, textArea);
function addTextAtCursorPosition(textArea, cursorPosition, text) {
    var front = (textArea.value).substring(0, cursorPosition);
    var back = (textArea.value).substring(cursorPosition, textArea.value.length);
    textArea.value = front + text + back;
function updateCursorPosition(cursorPosition, text, textArea) {
    cursorPosition = cursorPosition + text.length;
    textArea.selectionStart = cursorPosition;
    textArea.selectionEnd = cursorPosition;


    <button type="button" onclick="addTextAtCaret('textArea','Apple')">Insert Apple!</button>
    <button type="button" onclick="addTextAtCaret('textArea','Mango')">Insert Mango!</button>
    <button type="button" onclick="addTextAtCaret('textArea','Orange')">Insert Orange!</button>
<textarea id="textArea" rows="20" cols="50"></textarea>

How can I open a .db file generated by eclipse(android) form DDMS-->File explorer-->data--->data-->packagename-->database?

Download this Sqlite manager its the easiest one to use Sqlite manager

and drag and drop your fetched file on its running instance

only drawback of this Sqlite Manager it stop responding if you run some SQL statement that has Syntax Error in it.

So i Use Firefox Plugin Side by side also which you can find at FireFox addons

Convert a char to upper case using regular expressions (EditPad Pro)

You can also capitalize the first letter of the match using \I1 and \I2 etc instead of $1 and $2.

css - position div to bottom of containing div

Add position: relative to .outside. (

Elements that are positioned relatively are still considered to be in the normal flow of elements in the document. In contrast, an element that is positioned absolutely is taken out of the flow and thus takes up no space when placing other elements. The absolutely positioned element is positioned relative to nearest positioned ancestor. If a positioned ancestor doesn't exist, the initial container is used.

The "initial container" would be <body>, but adding the above makes .outside positioned.

How can I roll back my last delete command in MySQL?

If you didn't commit the transaction yet, try rollback. If you have already committed the transaction (by commit or by exiting the command line client), you must restore the data from your last backup.

How to empty a redis database?

You have two options:

  • FLUSHDB - clears currently active database
  • FLUSHALL - clears all the existing databases

How to control border height?

A border will always be at the full length of the containing box (the height of the element plus its padding), it can't be controlled except for adjusting the height of the element to which it applies. If all you need is a vertical divider, you could use:

<div id="left">
<span class="divider"></span>
<div id="right">

With css:

span {
 display: inline-block;
 width: 0;
 height: 1em;
 border-left: 1px solid #ccc;
 border-right: 1px solid #ccc;

Demo at JS Fiddle, adjust the height of the span.container to adjust the border 'height'.

Or, to use pseudo-elements (::before or ::after), given the following HTML:

<div id="left">content</div>
<div id="right">content</div>

The following CSS adds a pseudo-element before any div element that's the adjacent sibling of another div element:

div {
    display: inline-block;
    position: relative;

div + div {
    padding-left: 0.3em;

div + div::before {
    content: '';
    border-left: 2px solid #000;
    position: absolute;
    height: 50%;
    left: 0;
    top: 25%;

JS Fiddle demo.

Convenient C++ struct initialisation

You could use a lambda:

const FooBar fb = [&] {
    FooBar fb; = 12; = 3.4;
    return fb;

More information on this idiom can be found on Herb Sutter's blog.

Int to Decimal Conversion - Insert decimal point at specified location

Declare it as a decimal which uses the int variable and divide this by 100

int number = 700
decimal correctNumber = (decimal)number / 100;

Edit: Bala was faster with his reaction

How to forward declare a template class in namespace std?

there is a limited alternative you can use


class std_int_vector;

class A{
    std_int_vector* vector;
    virtual ~A();


#include "header.h"
#include <vector>
class std_int_vector: public std::vectror<int> {}

A::A() : vector(new std_int_vector()) {}

not tested in real programs, so expect it to be non-perfect.

Add params to given URL in Python


I've been not satisfied with all the solutions on this page (come on, where is our favorite copy-paste thing?) so I wrote my own based on answers here. It tries to be complete and more Pythonic. I've added a handler for dict and bool values in arguments to be more consumer-side (JS) friendly, but they are yet optional, you can drop them.

How it works

Test 1: Adding new arguments, handling Arrays and Bool values:

url = ''
new_params = {'answers': False, 'data': ['some','values']}

add_url_params(url, new_params) == \

Test 2: Rewriting existing args, handling DICT values:

url = ''
new_params = {'question': {'__X__':'__Y__'}}

add_url_params(url, new_params) == \

Talk is cheap. Show me the code.

Code itself. I've tried to describe it in details:

from json import dumps

    from urllib import urlencode, unquote
    from urlparse import urlparse, parse_qsl, ParseResult
except ImportError:
    # Python 3 fallback
    from urllib.parse import (
        urlencode, unquote, urlparse, parse_qsl, ParseResult

def add_url_params(url, params):
    """ Add GET params to provided URL being aware of existing.

    :param url: string of target URL
    :param params: dict containing requested params to be added
    :return: string with updated URL

    >> url = ''
    >> new_params = {'answers': False, 'data': ['some','values']}
    >> add_url_params(url, new_params)
    # Unquoting URL first so we don't loose existing args
    url = unquote(url)
    # Extracting url info
    parsed_url = urlparse(url)
    # Extracting URL arguments from parsed URL
    get_args = parsed_url.query
    # Converting URL arguments to dict
    parsed_get_args = dict(parse_qsl(get_args))
    # Merging URL arguments dict with new params

    # Bool and Dict values should be converted to json-friendly values
    # you may throw this part away if you don't like it :)
        {k: dumps(v) for k, v in parsed_get_args.items()
         if isinstance(v, (bool, dict))}

    # Converting URL argument to proper query string
    encoded_get_args = urlencode(parsed_get_args, doseq=True)
    # Creating new parsed result object based on provided with new
    # URL arguments. Same thing happens inside of urlparse.
    new_url = ParseResult(
        parsed_url.scheme, parsed_url.netloc, parsed_url.path,
        parsed_url.params, encoded_get_args, parsed_url.fragment

    return new_url

Please be aware that there may be some issues, if you'll find one please let me know and we will make this thing better

.jar error - could not find or load main class

You can always run this:

java -cp HelloWorld.jar HelloWorld

-cp HelloWorld.jar adds the jar to the classpath, then HelloWorld runs the class you wrote.

To create a runnable jar with a main class with no package, add Class-Path: . to the manifest:

Manifest-Version: 1.0
Class-Path: .
Main-Class: HelloWorld

I would advise using a package to give your class its own namespace. E.g.

package com.stackoverflow.user.blrp;

public class HelloWorld {

Can't push to the heroku

You need to follow the instructions displayed here, on your case follow scala configuration:

After setting up the getting started pack, tweak around the default config and apply to your local repository. It should work, just like mine using NodeJS.

HTH! :)

How to center content in a bootstrap column?

You can add float:none; margin:auto; styling to centerize column content.

How to convert hex to rgb using Java?

For JavaFX

import javafx.scene.paint.Color;


Color whiteColor = Color.valueOf("#ffffff");

"Permission Denied" trying to run Python on Windows 10


All of the files in %USERPROFILE%\AppData\Local\Microsoft\WindowsApps are placeholders that point to files that are actually located somewhere in C:\Program Files\WindowsApps, which happens to be denied permissions completely.

It appears I was on the right track with my statement made in my duplicate of this problem:

"Seems like they didn't really think about the distribution method screwing with permissions!"

Source: Cannot install pylint in Git Bash on Windows (Windows Store)

Permissions are screwed up royally because of the WindowsApps distribution method:

enter image description here enter image description here enter image description here Interestingly it says that the "Users" group can read and execute files, as well as my specific user, but the Administrators group can only List folder contents for some hilariously unfathomable reason. And when trying to access the folder in File Explorer, it refuses to even show the folder contents, so there's something fishy about that as well.

Interestingly, even though executing python in CMD works just fine, the "WindowsApps" folder does not show up when listing the files in the directory it resides in, and attempting to navigate into the folder generates a "Permission denied" error:

enter image description here

Attempting to change the permissions requires changing the owner first, so I changed the owner to the Administrators group. After that, I attempted to change the permissions for the Administrators group to include Full control, but it was unable to change this, because "access was denied" (duh, Micro$ucks, that's what we're trying to change!).

enter image description here

This permission error happened for so many files that I used Alt+C to quickly click "Continue" on repeat messages, but this still took too long, so I canceled the process, resulting in this warning message popping up:

enter image description here

And now I am unable to set the TrustedInstaller user back as the owner of the WindowsApps folder, because it doesn't show up in the list of Users/Groups/Built-in security principles/Other objects. *

enter image description here

*Actually, according to this tutorial, you can swap the owner back to TrustedInstaller by typing NT Service\TrustedInstaller into the object name text box.


There is no solution. Basically, we are completely screwed. Classy move, Microsoft.

jquery $('.class').each() how many items?

If you are using a version of jQuery that is less than version 1.8 you can use the $('.class').size() which takes zero parameters. See documentation for more information on .size() method.

However if you are using (or plan to upgrade) to 1.8 or greater you can use $('.class').length property. See documentation for more information on .length property.

Change background image opacity

What I did is:

<div id="bg-image"></div>
<div class="container">
    <h1>Hello World!</h1>


html {
    height: 100%;
    width: 100%;
body {
    height: 100%;
    width: 100%;
#bg-image {
    height: 100%;
    width: 100%;
    position: absolute;
    background-image: url(images/background.jpg);
    background-position: center center;
    background-repeat: no-repeat;
    background-size: cover;
    opacity: 0.3;

How to dynamically change header based on AngularJS partial view?

jkoreska's solution is perfect if you know the titles before hand, but you may need to set the title based on data you get from a resource etc.

My solution requires a single service. Since the rootScope is the base of all DOM elements, we don't need to put a controller on the html element like someone mentioned


app.service('Page', function($rootScope){
    return {
        setTitle: function(title){
            $rootScope.title = title;


doctype html
// ...

All controllers that need to change title

app.controller('SomeController', function(Page){
    Page.setTitle("Some Title");

How to enter newline character in Oracle?

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

Assign value from successful promise resolve to external variable

Your statement does nothing more than ask the interpreter to assign the value returned from then() to the vm.feed variable. then() returns you a Promise (as you can see here: You could picture this by seeing that the Promise (a simple object) is being pulled out of the function and getting assigned to vm.feed. This happens as soon as the interpreter executes that line.

Since your successful callback does not run when you call then() but only when your promise gets resolved (at a later time, asynchronously) it would be impossible for then() to return its value for the caller. This is the default way Javascript works. This was the exact reason Promises were introduced, so you could ask the interpreter to push the value to you, in the form of a callback.

Though on a future version that is being worked on for JavaScript (ES2016) a couple keywords will be introduced to work pretty much as you are expecting right now. The good news is you can start writing code like this today through transpilation from ES2016 to the current widely supported version (ES5).

A nice introduction to the topic is available at:

To use it right now you can transpile your code through Babel: (by running with --stage 1).

You can also see some examples here:

How to connect to a MS Access file (mdb) using C#?

The simplest way to connect is through an OdbcConnection using code like this

using System.Data.Odbc;

using(OdbcConnection myConnection = new OdbcConnection())
    myConnection.ConnectionString = myConnectionString;

    //execute queries, etc


where myConnectionString is something like this

myConnectionString = @"Driver={Microsoft Access Driver (*.mdb)};" + 

See ConnectionStrings

In alternative you could create a DSN and then use that DSN in your connection string

  • Open the Control Panel - Administrative Tools - ODBC Data Source Manager
  • Go to the System DSN Page and ADD a new DSN
  • Choose the Microsoft Access Driver (*.mdb) and press END
  • Set the Name of the DSN (choose MyDSN for this example)
  • Select the Database to be used
  • Try the Compact or Recover commands to see if the connection works

now your connectionString could be written in this way

myConnectionString = "DSN=myDSN;"

Is there a replacement for unistd.h for Windows (Visual C)?

Yes, there is:

Clone the repository and add path\to\libunistd\unistd to the INCLUDE environment variable.

Best way to log POST data in Apache?

An easier option may be to log the POST data before it gets to the server. For web applications, I use Burp Proxy and set Firefox to use it as an HTTP/S proxy, and then I can watch (and mangle) data 'on the wire' in real time.

For making API requests without a browser, SoapUI is very useful and may show similar info. I would bet that you could probably configure SoapUI to connect through Burp as well (just a guess though).

Change Row background color based on cell value DataTable

I Used rowCallBack datatable property it is working fine. PFB :-

"rowCallback": function (row, data, index) {

                        if ((data[colmindx] == 'colm_value')) { 
                        else if ((data[colmindx] == 'colm_value')) {

What is best way to start and stop hadoop ecosystem, with command line?

Starting (starts the namenode and the datanode) (starts the jobtracker and the tasktracker)


Encoding conversion in java

CharsetDecoder should be what you are looking for, no ?

Many network protocols and files store their characters with a byte-oriented character set such as ISO-8859-1 (ISO-Latin-1).
However, Java's native character encoding is Unicode UTF16BE (Sixteen-bit UCS Transformation Format, big-endian byte order).

See Charset. That doesn't mean UTF16 is the default charset (i.e.: the default "mapping between sequences of sixteen-bit Unicode code units and sequences of bytes"):

Every instance of the Java virtual machine has a default charset, which may or may not be one of the standard charsets.
[US-ASCII, ISO-8859-1 a.k.a. ISO-LATIN-1, UTF-8, UTF-16BE, UTF-16LE, UTF-16]
The default charset is determined during virtual-machine startup and typically depends upon the locale and charset being used by the underlying operating system.

This example demonstrates how to convert ISO-8859-1 encoded bytes in a ByteBuffer to a string in a CharBuffer and visa versa.

// Create the encoder and decoder for ISO-8859-1
Charset charset = Charset.forName("ISO-8859-1");
CharsetDecoder decoder = charset.newDecoder();
CharsetEncoder encoder = charset.newEncoder();

try {
    // Convert a string to ISO-LATIN-1 bytes in a ByteBuffer
    // The new ByteBuffer is ready to be read.
    ByteBuffer bbuf = encoder.encode(CharBuffer.wrap("a string"));

    // Convert ISO-LATIN-1 bytes in a ByteBuffer to a character ByteBuffer and then to a string.
    // The new ByteBuffer is ready to be read.
    CharBuffer cbuf = decoder.decode(bbuf);
    String s = cbuf.toString();
} catch (CharacterCodingException e) {

Rewrite left outer join involving multiple tables from Informix to Oracle

I'm guessing that you want something like

SELECT tab1.a, tab2.b, tab3.c, tab4.d
  FROM table1 tab1 
       JOIN table2 tab2 ON (tab1.fg = tab2.fg)
       LEFT OUTER JOIN table4 tab4 ON ( =
       LEFT OUTER JOIN table3 tab3 ON (tab4.xya = tab3.xya and tab3.desc = 'XYZ')
       LEFT OUTER JOIN table5 tab5 on (tab4.kk = tab5.kk AND
                                       tab3.dd = tab5.dd)

What is wrong with my SQL here? #1089 - Incorrect prefix key

Problem is the same for me in phpMyAdmin. I just created a table without any const. Later I modified the ID to a Primary key. Then I changed the ID to Auto-inc. That solved the issue.


Laravel 5: Display HTML with Blade

This works fine for Laravel 5.6

<?php echo "$text"; ?>

In a different way

{!! $text !!}

It will not render HTML code and print as a string.

For more details open link:- Display HTML with Blade

How do you rebase the current branch's changes on top of changes being merged in?

You've got what rebase does backwards. git rebase master does what you're asking for — takes the changes on the current branch (since its divergence from master) and replays them on top of master, then sets the head of the current branch to be the head of that new history. It doesn't replay the changes from master on top of the current branch.

A connection was successfully established with the server, but then an error occurred during the login process. (Error Number: 233)

the following points work for me. Try:

  1. start SSMS as administrator
  2. make sure SQL services are running. Change startup type to 'Automatic'

enter image description here

  1. In SSMS, in service instance property table, enable below:

enter image description here

Get OS-level system information

Have a look at the APIs available in the package. For example:

  • OperatingSystemMXBean.getSystemLoadAverage()
  • ThreadMXBean.getCurrentThreadCpuTime()
  • ThreadMXBean.getCurrentThreadUserTime()

There are loads of other useful things in there as well.

HorizontalAlignment=Stretch, MaxWidth, and Left aligned at the same time?

You can use this for the Width of your DataTemplate:

Width="{Binding ActualWidth,RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ScrollContentPresenter}}}"

Make sure your DataTemplate root has Margin="0" (you can use some panel as the root and set the Margin to the children of that root)

Php $_POST method to get textarea value

it is very simply. Just write your php value code between textarea tag.

<textarea id="contact_list"> <?php echo isset($_POST['contact_list']) ? $_POST['contact_list'] : '' ; ?> </textarea>

PivotTable's Report Filter using "greater than"

In an Excel pivot table, you are correct that a filter only allows values that are explicitly selected. If the filter field is placed on the pivot table rows or columns, however, you get a much wider set of Label Filter conditions, including Greater Than. If you did that in your case, then the added benefit would be that the various probability levels that match your condition are shown in the body of the table.

iterating over and removing from a map

You have to use Iterator to safely remove element while traversing a map.

How can I center text (horizontally and vertically) inside a div block?

Try the following example. I have added examples for each category: horizontal and vertical

<!DOCTYPE html>
                text-align: center;
                position: absolute;
                top: 50%;
                left: 50%;
                transform: translateX(-50%) translateY(-50%);
         <div id ="horizontal">Center horizontal text</div>
         <div id ="vertical">Center vertical text</div>

Open file dialog and select a file using WPF controls and C#

var ofd = new Microsoft.Win32.OpenFileDialog() {Filter = "JPEG Files (*.jpeg)|*.jpeg|PNG Files (*.png)|*.png|JPG Files (*.jpg)|*.jpg|GIF Files (*.gif)|*.gif"}; 
var result = ofd.ShowDialog();
if (result == false) return;
textBox1.Text = ofd.FileName;

Clear back stack using fragments

I posted something similar here

From Joachim's answer, from Dianne Hackborn:

I ended up just using:

FragmentManager fm = getActivity().getSupportFragmentManager();
for(int i = 0; i < fm.getBackStackEntryCount(); ++i) {    

But could equally have used something like:

((AppCompatActivity)getContext()).getSupportFragmentManager().popBackStack(String name, FragmentManager.POP_BACK_STACK_INCLUSIVE)

Which will pop all states up to the named one. You can then just replace the fragment with what you want

Get an OutputStream into a String

This worked nicely

OutputStream output = new OutputStream() {
    private StringBuilder string = new StringBuilder();

    public void write(int b) throws IOException {
        this.string.append((char) b );

    //Netbeans IDE automatically overrides this toString()
    public String toString() {
        return this.string.toString();

method call =>> marshaller.marshal( (Object) toWrite , (OutputStream) output);

then to print the string or get it just reference the "output" stream itself As an example, to print the string out to console =>> System.out.println(output);

FYI: my method call marshaller.marshal(Object,Outputstream) is for working with XML. It is irrelevant to this topic.

This is highly wasteful for productional use, there is a way too many conversion and it is a bit loose. This was just coded to prove to you that it is totally possible to create a custom OuputStream and output a string. But just go Horcrux7 way and all is good with merely two method calls.

And the world lives on another day....

Moving x-axis to the top of a plot in matplotlib



to place the tick marks at the top of the image. The command

ax.set_xlabel('X LABEL')    

affects the label, not the tick marks.

import matplotlib.pyplot as plt
import numpy as np
column_labels = list('ABCD')
row_labels = list('WXYZ')
data = np.random.rand(4, 4)
fig, ax = plt.subplots()
heatmap = ax.pcolor(data,

# put the major ticks at the middle of each cell
ax.set_xticks(np.arange(data.shape[1]) + 0.5, minor=False)
ax.set_yticks(np.arange(data.shape[0]) + 0.5, minor=False)

# want a more natural, table-like display

ax.set_xticklabels(column_labels, minor=False)
ax.set_yticklabels(row_labels, minor=False)

enter image description here

Creating a new dictionary in Python

Knowing how to write a preset dictionary is useful to know as well:

cmap =  {'US':'USA','GB':'Great Britain'}

# Explicitly:
# -----------
def cxlate(country):
        ret = cmap[country]
    except KeyError:
        ret = '?'
    return ret

present = 'US' # this one is in the dict
missing = 'RU' # this one is not

print cxlate(present) # == USA
print cxlate(missing) # == ?

# or, much more simply as suggested below:

print cmap.get(present,'?') # == USA
print cmap.get(missing,'?') # == ?

# with country codes, you might prefer to return the original on failure:

print cmap.get(present,present) # == USA
print cmap.get(missing,missing) # == RU

How to increase executionTimeout for a long-running query?

Execution Timeout is 90 seconds for .NET Framework 1.0 and 1.1, 110 seconds otherwise.

If you need to change defult settings you need to do it in your web.config under <httpRuntime>

<httpRuntime executionTimeout = "number(in seconds)"/>

But Remember:

This time-out applies only if the debug attribute in the compilation element is False.

Have look at in detail about compilation Element

Have look at this document about httpRuntime Element

javascript toISOString() ignores timezone offset

Using moment.js, you can use keepOffset parameter of toISOString:

toISOString(keepOffset?: boolean): string;


Clear text area

This method removes not only child (and other descendant) elements, but also any text within the set of matched elements. This is because, according to the DOM specification, any string of text within an element is considered a child node of that element.


Current date without time

Use the Date property: Gets the date component of this instance.

var dateAndTime = DateTime.Now;
var date = dateAndTime.Date;

variable date contain the date and the time part will be 00:00:00.




DateTime.ToShortDateString Method-

Console.WriteLine(DateTime.Now.ToShortDateString ());

Setting PATH environment variable in OSX permanently

You have to add it to /etc/paths.

Reference (which works for me) : Here

What is ADT? (Abstract Data Type)

ADT is a set of objects and operations, no where in an ADT’s definitions is there any mention of how the set of operations is implemented. Programmers who use collections only need to know how to instantiate and access data in some pre-determined manner, without concerns for the details of the collections implementations. In other words, from a user’s perspective, a collection is an abstraction, and for this reason, in computer science, some collections are referred to as abstract data types (ADTs). The user is only concern with learning its interface, or the set of operations its performs...more

How should I make my VBA code compatible with 64-bit Windows?

Use PtrSafe and see how that works on Excel 2010.

Corrected typo from the book "Microsoft Excel 2010 Power Programming with VBA".

#If vba7 and win64 then
  declare ptrsafe function ....
  declare function ....
#End If

val(application.version)>12.0 won't work because Office 2010 has both 32 and 64 bit versions

Pygame mouse clicking detection

I assume your game has a main loop, and all your sprites are in a list called sprites.

In your main loop, get all events, and check for the MOUSEBUTTONDOWN or MOUSEBUTTONUP event.

while ... # your main loop
  # get all events
  ev = pygame.event.get()

  # proceed events
  for event in ev:

    # handle MOUSEBUTTONUP
    if event.type == pygame.MOUSEBUTTONUP:
      pos = pygame.mouse.get_pos()

      # get a list of all sprites that are under the mouse cursor
      clicked_sprites = [s for s in sprites if s.rect.collidepoint(pos)]
      # do something with the clicked sprites...

So basically you have to check for a click on a sprite yourself every iteration of the mainloop. You'll want to use mouse.get_pos() and rect.collidepoint().

Pygame does not offer event driven programming, as e.g. cocos2d does.

Another way would be to check the position of the mouse cursor and the state of the pressed buttons, but this approach has some issues.

if pygame.mouse.get_pressed()[0] and mysprite.rect.collidepoint(pygame.mouse.get_pos()):
  print ("You have opened a chest!")

You'll have to introduce some kind of flag if you handled this case, since otherwise this code will print "You have opened a chest!" every iteration of the main loop.

handled = False

while ... // your loop

  if pygame.mouse.get_pressed()[0] and mysprite.rect.collidepoint(pygame.mouse.get_pos()) and not handled:
    print ("You have opened a chest!")
    handled = pygame.mouse.get_pressed()[0]

Of course you can subclass Sprite and add a method called is_clicked like this:

class MySprite(Sprite):

  def is_clicked(self):
    return pygame.mouse.get_pressed()[0] and self.rect.collidepoint(pygame.mouse.get_pos())

So, it's better to use the first approach IMHO.

Dialog with transparent background in Android

For anyone using a custom dialog with a custom class you need to change the transparency in the class add this line in the onCreate():


How to get Toolbar from fragment?

In case fragments should have custom view of ToolBar you can implement ToolBar for each fragment separately.

add ToolBar into fragment_layout:


find it in fragment:

    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment, container, false);
        Toolbar toolbar = (Toolbar) view.findViewById(;

        //set toolbar appearance

        //for crate home button
        AppCompatActivity activity = (AppCompatActivity) getActivity();

menu listener could be created two ways: override onOptionsItemSelected in your fragment:

public boolean onOptionsItemSelected(MenuItem item) {
    return super.onOptionsItemSelected(item);

or set listener for toolbar when create it in onCreateView():

toolbar.setOnMenuItemClickListener(new Toolbar.OnMenuItemClickListener() {
            public boolean onMenuItemClick(MenuItem menuItem) {
                return false;

ios simulator: how to close an app

You can also kill the app by process id

ps -cx -o pid,command | awk '$2 == "YourAppNameCaseSensitive" { print $1 }' | xargs kill -9

Timeout jQuery effects

Ben Alman wrote a sweet plugin for jQuery called doTimeout. It has a lot of nice features!

Check it out here: jQuery doTimeout: Like setTimeout, but better.

HTTP Headers for File Downloads

As explained by Alex's link you're probably missing the header Content-Disposition on top of Content-Type.

So something like this:

Content-Disposition: attachment; filename="MyFileName.ext"

How do I jump out of a foreach loop in C#?

foreach (string s in sList)
    if (s.equals("ok"))
        return true;

return false;

Alternatively, if you need to do some other things after you've found the item:

bool found = false;
foreach (string s in sList)
    if (s.equals("ok"))
        found = true;
        break; // get out of the loop

// do stuff

return found;

Building a complete online payment gateway like Paypal

What you're talking about is becoming a payment service provider. I have been there and done that. It was a lot easier about 10 years ago than it is now, but if you have a phenomenal amount of time, money and patience available, it is still possible.

You will need to contact an acquiring bank. You didnt say what region of the world you are in, but by this I dont mean a local bank branch. Each major bank will generally have a separate card acquiring arm. So here in the UK we have (eg) Natwest bank, which uses Streamline (or Worldpay) as its acquiring arm. In total even though we have scores of major banks, they all end up using one of five or so card acquirers.

Happily, all UK card acquirers use a standard protocol for communication of authorisation requests, and end of day settlement. You will find minor quirks where some acquiring banks support some features and have slightly different syntax, but the differences are fairly minor. The UK standards are published by the Association for Payment Clearing Services (APACS) (which is now known as the UKPA). The standards are still commonly referred to as APACS 30 (authorization) and APACS 29 (settlement), but are now formally known as APACS 70 (books 1 through 7).

Although the APACS standard is widely supported across the UK (Amex and Discover accept messages in this format too) it is not used in other countries - each country has it's own - for example: Carte Bancaire in France, CartaSi in Italy, Sistema 4B in Spain, Dankort in Denmark etc. An effort is under way to unify the protocols across Europe - see

Communicating with the acquiring bank can be done a number of ways. Again though, it will depend on your region. In the UK (and most of Europe) we have one communications gateway that provides connectivity to all the major acquirers, they are called TNS and there are dozens of ways of communicating through them to the acquiring bank, from dialup 9600 baud modems, ISDN, HTTPS, VPN or dedicated line. Ultimately the authorisation request will be converted to X25 protocol, which is the protocol used by these acquiring banks when communicating with each other.

In summary then: it all depends on your region.

  • Contact a major bank and try to get through to their card acquiring arm.
  • Explain that you're setting up as a payment service provider, and request details on comms format for authorization requests and end of day settlement files
  • Set up a test merchant account and develop auth/settlement software and go through the accreditation process. Most acquirers help you through this process for free, but when you want to register as an accredited PSP some will request a fee.
  • you will need to comply with some regulations too, for example you may need to register as a payment institution

Once you are registered and accredited you'll then be able to accept customers and set up merchant accounts on behalf of the bank/s you're accredited against (bearing in mind that each acquirer will generally support multiple banks). Rinse and repeat with other acquirers as you see necessary.

Beyond that you have lots of other issues, mainly dealing with PCI-DSS. Thats a whole other topic and there are already some q&a's on this site regarding that. Like I say, its a phenomenal undertaking - most likely a multi-year project even for a reasonably sized team, but its certainly possible.

Change the background color of a row in a JTable

Resumee of Richard Fearn's answer , to make each second line gray:

jTable.setDefaultRenderer(Object.class, new DefaultTableCellRenderer()
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column)
        final Component c = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
        c.setBackground(row % 2 == 0 ? Color.LIGHT_GRAY : Color.WHITE);
        return c;

Updating and committing only a file's permissions using git version control

By default, git will update execute file permissions if you change them. It will not change or track any other permissions.

If you don't see any changes when modifying execute permission, you probably have a configuration in git which ignore file mode.

Look into your project, in the .git folder for the config file and you should see something like this:

    filemode = false

You can either change it to true in your favorite text editor, or run:

git config core.filemode true

Then, you should be able to commit normally your files. It will only commit the permission changes.

Purpose of a constructor in Java?

A constructor initializes an object when it is created . It has the same name as its class and is syntactically similar to a method , but constructor have no expicit return type.Typically , we use constructor to give initial value to the instance variables defined by the class , or to perform any other startup procedures required to make a fully formed object.

Here is an example of constructor:

class queen(){
   int beauty;

     beauty = 98;

class constructor demo{
    public static void main(String[] args){
       queen arth = new queen();
       queen y = new queen();

       System.out.println(" ";


output is:

98 98

Here the construcor is :

beauty =98;

Now the turn of parameterized constructor.

  class queen(){
   int beauty;

   queen(int x){ 
     beauty = x;

class constructor demo{
    public static void main(String[] args){
       queen arth = new queen(100);
       queen y = new queen(98);

       System.out.println(" ";


output is:

100 98

Getting next element while cycling through a list

After thinking this through carefully, I think this is the best way. It lets you step off in the middle easily without using break, which I think is important, and it requires minimal computation, so I think it's the fastest. It also doesn't require that li be a list or tuple. It could be any iterator.

from itertools import cycle

li = [0, 1, 2, 3]

running = True
licycle = cycle(li)
# Prime the pump
nextelem = next(licycle)
while running:
    thiselem, nextelem = nextelem, next(licycle)

I'm leaving the other solutions here for posterity.

All of that fancy iterator stuff has its place, but not here. Use the % operator.

li = [0, 1, 2, 3]

running = True
while running:
    for idx, elem in enumerate(li):
        thiselem = elem
        nextelem = li[(idx + 1) % len(li)]

Now, if you intend to infinitely cycle through a list, then just do this:

li = [0, 1, 2, 3]

running = True
idx = 0
while running:
    thiselem = li[idx]
    idx = (idx + 1) % len(li)
    nextelem = li[idx]

I think that's easier to understand than the other solution involving tee, and probably faster too. If you're sure the list won't change size, you can squirrel away a copy of len(li) and use that.

This also lets you easily step off the ferris wheel in the middle instead of having to wait for the bucket to come down to the bottom again. The other solutions (including yours) require you check running in the middle of the for loop and then break.

Finding out the name of the original repository you cloned from in Git

Edited for clarity:

This will work to to get the value if the remote.origin.url is in the form protocol://auth_info@git_host:port/project/repo.git. If you find it doesn't work, adjust the -f5 option that is part of the first cut command.

For the example remote.origin.url of protocol://auth_info@git_host:port/project/repo.git the output created by the cut command would contain the following:

-f1: protocol: -f2: (blank) -f3: auth_info@git_host:port -f4: project -f5: repo.git

If you are having problems, look at the output of the git config --get remote.origin.url command to see which field contains the original repository. If the remote.origin.url does not contain the .git string then omit the pipe to the second cut command.

#!/usr/bin/env bash
repoSlug="$(git config --get remote.origin.url | cut -d/ -f5 | cut -d. -f1)"
echo ${repoSlug}

Batch File: ( was unexpected at this time

you need double quotes in all your three if statements, eg.:

IF "%a%"=="2" (

title ~USB Wizard~
echo What do you want to do?
echo 1.Enable/Disable USB Storage Devices.
echo 2.Enable/Disable Writing Data onto USB Storage.
echo 3.~Yet to come~.

set "a=%globalparam1%"
goto :aCheck
set /p "a=Enter Choice: "
if "%a%"=="" goto :aPrompt
echo %a%

IF "%a%"=="2" (
    title USB WRITE LOCK
    echo What do you want to do?
    echo 1.Apply USB Write Protection
    echo 2.Remove USB Write Protection
    set "param1=%globalparam2%"
    goto :param1Check
    set /p "param1=Enter Choice: "
    if "!param1!"=="" goto :param1Prompt

    if "!param1!"=="1" (
         REG ADD HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies\ /v WriteProtect /t REG_DWORD /d 00000001
         USB Write is Locked!
    if "!param1!"=="2" (
         REG ADD HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\StorageDevicePolicies\ /v WriteProtect /t REG_DWORD /d 00000000
         USB Write is Unlocked!

Login failed for user 'NT AUTHORITY\NETWORK SERVICE'

I was experiencing a similar error message that I noticed in the Windows Event Viewer that read:

Login failed for user 'NT AUTHORITY\NETWORK SERVICE'. Reason: Failed to open the explicitly specified database. [CLIENT: local machine]

The solution that resolved my problem was:

  1. Login to SqlExpress via SQL Server Management Studio
  2. Go to the "Security" directory of the database
  3. Right-click the Users directory
  4. Select "New User..."
  5. Add 'NT AUTHORITY\NETWORK SERVICE' as a new user
  6. In the Data Role Membership area, select db_owner
  7. Click OK

Here's a screenshot of the above: Screenshot of adding new user Network Service as db_owner to SqlExpress

How to get class object's name as a string in Javascript?

Some time ago, I used this.

Perhaps you could try:

    var my_var = function get_this_name(){
        alert("I " + this.init());
    my_var.prototype.init = function(){
    new my_var();

Pop an Alert: "I get_this_name".

How to add button tint programmatically

this is easily handled in the new Material Button from material design library, first, add the dependency:

implementation ''

then in your XML, use this for your button:

    app:backgroundTint="@color/grayBackground_500" />

and when you want to change the color, here's the code in Kotlin, It's not deprecated and it can be used prior to Android 21:

accept.backgroundTintList = ColorStateList.valueOf(ResourcesCompat.getColor(resources, 
R.color.colorPrimary, theme))

In Tensorflow, get the names of all the Tensors in a graph

I'll try to summarize the answers:

To get all nodes in the graph: (type tensorflow.core.framework.node_def_pb2.NodeDef)

all_nodes = [n for n in tf.get_default_graph().as_graph_def().node]

To get all ops in the graph: (type tensorflow.python.framework.ops.Operation)

all_ops = tf.get_default_graph().get_operations()

To get all variables in the graph: (type tensorflow.python.ops.resource_variable_ops.ResourceVariable)

all_vars = tf.global_variables()

To get all tensors in the graph: (type tensorflow.python.framework.ops.Tensor)

all_tensors = [tensor for op in tf.get_default_graph().get_operations() for tensor in op.values()]

To get all placeholders in the graph: (type tensorflow.python.framework.ops.Tensor)

all_placeholders = [placeholder for op in tf.get_default_graph().get_operations() if op.type=='Placeholder' for placeholder in op.values()]

Tensorflow 2

To get the graph in Tensorflow 2, instead of tf.get_default_graph() you need to instantiate a tf.function first and access the graph attribute, for example:

graph = func.get_concrete_function().graph

where func is a tf.function

T-SQL loop over query results


FROM   table


    FROM @getid INTO @id, @name

    EXEC stored_proc @varName=@id, @otherVarName='test', @varForName=@name


CLOSE @getid

Git pushing to remote branch

Simply push this branch to a different branch name

 git push -u origin localBranch:remoteBranch

AngularJS : Prevent error $digest already in progress when calling $scope.$apply()

yearofmoo did a great job at creating a reusable $safeApply function for us :

Usage :

//use by itself

//tell it which scope to update

//pass in an update function that gets called when the digest is going on...
$scope.$safeApply(function() {


//pass in both a scope and a function
$scope.$safeApply($anotherScope,function() {


//call it on the rootScope
$rootScope.$safeApply($scope, fn);

How to use jQuery Plugin with Angular 4?

Try this:

import * as $ from 'jquery/dist/jquery.min.js';

Or add scripts to angular-cli.json:

"scripts": [

and in your .ts file:

declare var $: any;

Python Script to convert Image into Byte array

with BytesIO() as output:
    from PIL import Image
    with as img:
        img.convert('RGB').save(output, 'BMP')                
    data = output.getvalue()[14:]

I just use this for add a image to clipboard in windows.

How does Python manage int and long?

It manages them because int and long are sibling class definitions. They have appropriate methods for +, -, *, /, etc., that will produce results of the appropriate class.

For example

>>> a=1<<30
>>> type(a)
<type 'int'>
>>> b=a*2
>>> type(b)
<type 'long'>

In this case, the class int has a __mul__ method (the one that implements *) which creates a long result when required.

Why can't I use background image and color together?

Hello everyone I tried another way to combine background-image and background-color together:


<article><canvas id="color"></canvas></article>


article {
  height: 490px;
  background: url("Your IMAGE") no-repeat center cover;

  width: 100%; 
  height: 490px; 
  opacity: 0.9;


window.onload = init();

var canvas, ctx;

function init(){
  canvas = document.getElementeById('color'); 
  ctx = canvas.getContext('2d');;  
  ctx.fillstyle = '#00833d'; 

Please let me know if it worked for you Thanks

Difference between VARCHAR and TEXT in MySQL



  • fixed max size of 65535 characters (you cannot limit the max size)
  • takes 2 + c bytes of disk space, where c is the length of the stored string.
  • cannot be (fully) part of an index. One would need to specify a prefix length.


  • variable max size of M characters
  • M needs to be between 1 and 65535
  • takes 1 + c bytes (for M ≤ 255) or 2 + c (for 256 ≤ M ≤ 65535) bytes of disk space where c is the length of the stored string
  • can be part of an index

More Details

TEXT has a fixed max size of 2¹6-1 = 65535 characters.
VARCHAR has a variable max size M up to M = 2¹6-1.
So you cannot choose the size of TEXT but you can for a VARCHAR.

The other difference is, that you cannot put an index (except for a fulltext index) on a TEXT column.
So if you want to have an index on the column, you have to use VARCHAR. But notice that the length of an index is also limited, so if your VARCHAR column is too long you have to use only the first few characters of the VARCHAR column in your index (See the documentation for CREATE INDEX).

But you also want to use VARCHAR, if you know that the maximum length of the possible input string is only M, e.g. a phone number or a name or something like this. Then you can use VARCHAR(30) instead of TINYTEXT or TEXT and if someone tries to save the text of all three "Lord of the Ring" books in your phone number column you only store the first 30 characters :)

Edit: If the text you want to store in the database is longer than 65535 characters, you have to choose MEDIUMTEXT or LONGTEXT, but be careful: MEDIUMTEXT stores strings up to 16 MB, LONGTEXT up to 4 GB. If you use LONGTEXT and get the data via PHP (at least if you use mysqli without store_result), you maybe get a memory allocation error, because PHP tries to allocate 4 GB of memory to be sure the whole string can be buffered. This maybe also happens in other languages than PHP.

However, you should always check the input (Is it too long? Does it contain strange code?) before storing it in the database.

Notice: For both types, the required disk space depends only on the length of the stored string and not on the maximum length.
E.g. if you use the charset latin1 and store the text "Test" in VARCHAR(30), VARCHAR(100) and TINYTEXT, it always requires 5 bytes (1 byte to store the length of the string and 1 byte for each character). If you store the same text in a VARCHAR(2000) or a TEXT column, it would also require the same space, but, in this case, it would be 6 bytes (2 bytes to store the string length and 1 byte for each character).

For more information have a look at the documentation.

Finally, I want to add a notice, that both, TEXT and VARCHAR are variable length data types, and so they most likely minimize the space you need to store the data. But this comes with a trade-off for performance. If you need better performance, you have to use a fixed length type like CHAR. You can read more about this here.

Multiple Updates in MySQL

All of the following applies to InnoDB.

I feel knowing the speeds of the 3 different methods is important.

There are 3 methods:

  2. TRANSACTION: Where you do an update for each record within a transaction
  3. CASE: In which you a case/when for each different record within an UPDATE

I just tested this, and the INSERT method was 6.7x faster for me than the TRANSACTION method. I tried on a set of both 3,000 and 30,000 rows.

The TRANSACTION method still has to run each individually query, which takes time, though it batches the results in memory, or something, while executing. The TRANSACTION method is also pretty expensive in both replication and query logs.

Even worse, the CASE method was 41.1x slower than the INSERT method w/ 30,000 records (6.1x slower than TRANSACTION). And 75x slower in MyISAM. INSERT and CASE methods broke even at ~1,000 records. Even at 100 records, the CASE method is BARELY faster.

So in general, I feel the INSERT method is both best and easiest to use. The queries are smaller and easier to read and only take up 1 query of action. This applies to both InnoDB and MyISAM.

Bonus stuff:

The solution for the INSERT non-default-field problem is to temporarily turn off the relevant SQL modes: SET SESSION sql_mode=REPLACE(REPLACE(@@SESSION.sql_mode,"STRICT_TRANS_TABLES",""),"STRICT_ALL_TABLES",""). Make sure to save the sql_mode first if you plan on reverting it.

As for other comments I've seen that say the auto_increment goes up using the INSERT method, this does seem to be the case in InnoDB, but not MyISAM.

Code to run the tests is as follows. It also outputs .SQL files to remove php interpreter overhead


//These 2 functions need to be filled in
function InitSQL()

function RunSQLQuery($Q)


//Run the 3 tests
    RunTest($i, $NumRows);

function RunTest($TestNum, $NumRows)
    $DoQuery=function($Query) use (&$TheQueries)

    $DoQuery('DROP TABLE IF EXISTS '.$TableName);
    $DoQuery('CREATE TABLE '.$TableName.' (i1 int NOT NULL AUTO_INCREMENT, i2 int NOT NULL, primary key (i1)) ENGINE=InnoDB');
    $DoQuery('INSERT INTO '.$TableName.' (i2) VALUES ('.implode('), (', range(2, $NumRows+1)).')');

        $DoQuery('START TRANSACTION');
            $DoQuery('UPDATE '.$TableName.' SET i2='.(($i+5)*1000).' WHERE i1='.$i);
            $Query[]=sprintf("(%d,%d)", $i, (($i+5)*1000));
        $DoQuery('INSERT INTO '.$TableName.' VALUES '.implode(', ', $Query).' ON DUPLICATE KEY UPDATE i2=VALUES(i2)');
            $Query[]=sprintf('WHEN %d THEN %d', $i, (($i+5)*1000));
        $DoQuery("UPDATE $TableName SET i2=CASE i1\n".implode("\n", $Query)."\nEND\nWHERE i1 IN (".implode(',', range(1, $NumRows)).')');
    print "$TestName: ".(microtime(true)-$Start)."<br>\n";

    file_put_contents("./$TestName.sql", implode(";\n", $TheQueries).';');

Draw in Canvas by finger, Android

I think it's important to add a thing, if you use the layout inflation that constructor in the drawview is not correct, add these constructors in the class:

public DrawingView(Context c, AttributeSet attrs) {
    super(c, attrs);

public DrawingView(Context c, AttributeSet attrs, int defStyle) {
    super(c, attrs, defStyle);

or the android system fails to inflate the layout file. I hope this could to help.

Execute PHP script in cron job

You may need to run the cron job as a user with permissions to execute the PHP script. Try executing the cron job as root, using the command runuser (man runuser). Or create a system crontable and run the PHP script as an authorized user, as @Philip described.

I provide a detailed answer how to use cron in this stackoverflow post.

How to write a cron that will run a script every day at midnight?

How to specify a editor to open crontab file? "export EDITOR=vi" does not work

This worked for me :

export EDITOR

Add this to ~/.bash_profile or ~/.bashrc to enable this for current user.

What do parentheses surrounding an object/function/class declaration mean?

It is a self-executing anonymous function. The first set of parentheses contain the expressions to be executed, and the second set of parentheses executes those expressions.

It is a useful construct when trying to hide variables from the parent namespace. All the code within the function is contained in the private scope of the function, meaning it can't be accessed at all from outside the function, making it truly private.


How to query a CLOB column in Oracle

When getting the substring of a CLOB column and using a query tool that has size/buffer restrictions sometimes you would need to set the BUFFER to a larger size. For example while using SQL Plus use the SET BUFFER 10000 to set it to 10000 as the default is 4000.

Running the DBMS_LOB.substr command you can also specify the amount of characters you want to return and the offset from which. So using DBMS_LOB.substr(column, 3000) might restrict it to a small enough amount for the buffer.

See oracle documentation for more info on the substr command

       lob_loc     IN    CLOB   CHARACTER SET ANY_CS,
       amount      IN    INTEGER := 32767,
       offset      IN    INTEGER := 1)

How to find the path of the local git repository when I am possibly in a subdirectory

git rev-parse --show-toplevel

could be enough if executed within a git repo.
From git rev-parse man page:


Show the absolute path of the top-level directory.

For older versions (before 1.7.x), the other options are listed in "Is there a way to get the git root directory in one command?":

git rev-parse --git-dir

That would give the path of the .git directory.

The OP mentions:

git rev-parse --show-prefix

which returns the local path under the git repo root. (empty if you are at the git repo root)

Note: for simply checking if one is in a git repo, I find the following command quite expressive:

git rev-parse --is-inside-work-tree

And yes, if you need to check if you are in a .git git-dir folder:

git rev-parse --is-inside-git-dir

Converting milliseconds to a date (jQuery/JavaScript)

Below is a snippet to enable you format the date to a desirable output:

var time = new Date();
var time = time.getTime();

var theyear = time.getFullYear();
var themonth = time.getMonth() + 1;
var thetoday = time.getDate();

document.write("The date is: ");
document.write(theyear + "/" + themonth + "/" + thetoday);

Dump a list in a pickle file and retrieve it back later

Pickling will serialize your list (convert it, and it's entries to a unique byte string), so you can save it to disk. You can also use pickle to retrieve your original list, loading from the saved file.

So, first build a list, then use pickle.dump to send it to a file...

Python 3.4.1 (default, May 21 2014, 12:39:51) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> mylist = ['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>> import pickle
>>> with open('parrot.pkl', 'wb') as f:
...   pickle.dump(mylist, f)

Then quit and come back later… and open with pickle.load...

Python 3.4.1 (default, May 21 2014, 12:39:51) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pickle
>>> with open('parrot.pkl', 'rb') as f:
...   mynewlist = pickle.load(f)
>>> mynewlist
['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]

Where is android_sdk_root? and how do I set it.?

Open the terminal and run the command: nano $HOME/.bashrc aggregate the follow line:

export ANDROID_HOME=$HOME/Android/Sdk
export ANDROID_SDK_ROOT=$HOME/Android/Sdk
export PATH=$PATH:$ANDROID_HOME/platform-tools

Ctrl+o save and ctrl+x close.

And run the command:

source $HOME/.bashrc


How to write new line character to a file in Java

Split the string in to string array and write using above method (I assume your text contains \n to get new line)

String[] test = test.split("\n");

and the inside a loop


How to convert Nonetype to int or string?

In some situations it is helpful to have a function to convert None to int zero:

def nz(value):

    Convert None to int zero else return value.

    if value == None:
        return 0
    return value

Delaying AngularJS route change until model loaded to prevent flicker

One possible solution might be to use the ng-cloak directive with the element where we are using the models e.g.

<div ng-cloak="">
  Value in  myModel is: {{myModel}}

I think this one takes least effort.

Stop UIWebView from "bouncing" vertically?

It looks to me like the UIWebView has a UIScrollView. You can use documented APIs for this, but bouncing is set for both directions, not individually. This is in the API docs. UIScrollView has a bounce property, so something like this works (don't know if there's more than one scrollview):

NSArray *subviews = myWebView.subviews;
NSObject *obj = nil;
int i = 0;
for (; i < subviews.count ; i++)
    obj = [subviews objectAtIndex:i];

    if([[obj class] isSubclassOfClass:[UIScrollView class]] == YES)
        ((UIScrollView*)obj).bounces = NO;

MessageBox with YesNoCancel - No & Cancel triggers same event

The way I use a yes/no prompt is:

If MsgBox("Are you sure?", MsgBoxStyle.YesNo) <> MsgBoxResults.Yes Then
    Exit Sub
End If

Flatten nested dictionaries, compressing keys

Utilizing recursion, keeping it simple and human readable:

def flatten_dict(dictionary, accumulator=None, parent_key=None, separator="."):
    if accumulator is None:
        accumulator = {}

    for k, v in dictionary.items():
        k = f"{parent_key}{separator}{k}" if parent_key else k
        if isinstance(v, dict):
            flatten_dict(dictionary=v, accumulator=accumulator, parent_key=k)

        accumulator[k] = v

    return accumulator

Call is simple:

new_dict = flatten_dict(dictionary)


new_dict = flatten_dict(dictionary, separator="_")

if we want to change the default separator.

A little breakdown:

When the function is first called, it is called only passing the dictionary we want to flatten. The accumulator parameter is here to support recursion, which we see later. So, we instantiate accumulator to an empty dictionary where we will put all of the nested values from the original dictionary.

if accumulator is None:
    accumulator = {}

As we iterate over the dictionary's values, we construct a key for every value. The parent_key argument will be None for the first call, while for every nested dictionary, it will contain the key pointing to it, so we prepend that key.

k = f"{parent_key}{separator}{k}" if parent_key else k

In case the value v the key k is pointing to is a dictionary, the function calls itself, passing the nested dictionary, the accumulator (which is passed by reference, so all changes done to it are done on the same instance) and the key k so that we can construct the concatenated key. Notice the continue statement. We want to skip the next line, outside of the if block, so that the nested dictionary doesn't end up in the accumulator under key k.

if isinstance(v, dict):
    flatten_dict(dict=v, accumulator=accumulator, parent_key=k)

So, what do we do in case the value v is not a dictionary? Just put it unchanged inside the accumulator.

accumulator[k] = v

Once we're done we just return the accumulator, leaving the original dictionary argument untouched.


This will work only with dictionaries that have strings as keys. It will work with hashable objects implementing the __repr__ method, but will yield unwanted results.

How to Inspect Element using Safari Browser

In your Safari menu bar click Safari > Preferences & then select the Advanced tab.

Select: "Show Develop menu in menu bar"

Now you can click Develop in your menu bar and choose Show Web Inspector

You can also right-click and press "Inspect element".

How do I concatenate two strings in Java?

There are multiple ways to do so, but Oracle and IBM say that using +, is a bad practice, because essentially every time you concatenate String, you end up creating additional objects in memory. It will utilize extra space in JVM, and your program may be out of space, or slow down.

Using StringBuilder or StringBuffer is best way to go with it. Please look at Nicolas Fillato's comment above for example related to StringBuffer.

String first = "I eat";  String second = "all the rats."; 

Pandas unstack problems: ValueError: Index contains duplicate entries, cannot reshape

Here's an example DataFrame which show this, it has duplicate values with the same index. The question is, do you want to aggregate these or keep them as multiple rows?

In [11]: df
   0  1  2      3
0  1  2  a  16.86
1  1  2  a  17.18
2  1  4  a  17.03
3  2  5  b  17.28

In [12]: df.pivot_table(values=3, index=[0, 1], columns=2, aggfunc='mean')  # desired?
2        a      b
0 1
1 2  17.02    NaN
  4  17.03    NaN
2 5    NaN  17.28

In [13]: df1 = df.set_index([0, 1, 2])

In [14]: df1
0 1 2
1 2 a  16.86
    a  17.18
  4 a  17.03
2 5 b  17.28

In [15]: df1.unstack(2)
ValueError: Index contains duplicate entries, cannot reshape

One solution is to reset_index (and get back to df) and use pivot_table.

In [16]: df1.reset_index().pivot_table(values=3, index=[0, 1], columns=2, aggfunc='mean')
2        a      b
0 1
1 2  17.02    NaN
  4  17.03    NaN
2 5    NaN  17.28

Another option (if you don't want to aggregate) is to append a dummy level, unstack it, then drop the dummy level...

How do I access refs of a child component in the parent component

First access the children with: this.props.children, each child will then have its ref as a property on it.

How to save an image to localStorage and display it on the next page?

I wrote a little 2,2kb library of saving image in localStorage JQueryImageCaching Usage:

<img data-src="path/to/image">

Trigger a Travis-CI rebuild without pushing a commit?

If the build never occurred (perhaps you didn't get the Pull-Request build switch set to on in time), you can mark the Pull Request on Github as closed then mark it as opened and a new build will be triggered.

Comparing two dictionaries and checking how many (key, value) pairs are equal


def equal(a, b):
    type_a = type(a)
    type_b = type(b)
    if type_a != type_b:
        return False
    if isinstance(a, dict):
        if len(a) != len(b):
            return False
        for key in a:
            if key not in b:
                return False
            if not equal(a[key], b[key]):
                return False
        return True

    elif isinstance(a, list):
        if len(a) != len(b):
            return False
        while len(a):
            x = a.pop()
            index = indexof(x, b)
            if index == -1:
                return False
            del b[index]
        return True
        return a == b

def indexof(x, a):
    for i in range(len(a)):
        if equal(x, a[i]):
            return i
    return -1


>>> a = {
    'number': 1,
    'list': ['one', 'two']
>>> b = {
    'list': ['two', 'one'],
    'number': 1
>>> equal(a, b)

Run git pull over all subdirectories

I use this

for dir in $(find . -name ".git")
do cd ${dir%/*}
    echo $PWD
    git pull
    echo ""
    cd - > /dev/null


postgres default timezone

What if you set the timezone of the role you are using?

ALTER ROLE my_db_user IN DATABASE my_database
    SET "TimeZone" TO 'UTC';

Will this be of any use?

Python/BeautifulSoup - how to remove all tags from an element?

Code to simply get the contents as text instead of html:

'html_text' parameter is the string which you will pass in this function to get the text

from bs4 import BeautifulSoup

soup = BeautifulSoup(html_text, 'lxml')
text = soup.get_text()

How do I detect a page refresh using jquery?

   //do something

But this wont save any info for later, unless you were planning on saving that in a cookie somewhere (or local storage) and the unload event does not always fire in all browsers.




     //save info somewhere

    return 'are you sure you want to leave?';


Aren't promises just callbacks?

Yes, Promises are asynchronous callbacks. They can't do anything that callbacks can't do, and you face the same problems with asynchrony as with plain callbacks.

However, Promises are more than just callbacks. They are a very mighty abstraction, allow cleaner and better, functional code with less error-prone boilerplate.

So what's the main idea?

Promises are objects representing the result of a single (asynchronous) computation. They resolve to that result only once. There's a few things what this means:

Promises implement an observer pattern:

  • You don't need to know the callbacks that will use the value before the task completes.
  • Instead of expecting callbacks as arguments to your functions, you can easily return a Promise object
  • The promise will store the value, and you can transparently add a callback whenever you want. It will be called when the result is available. "Transparency" implies that when you have a promise and add a callback to it, it doesn't make a difference to your code whether the result has arrived yet - the API and contracts are the same, simplifying caching/memoisation a lot.
  • You can add multiple callbacks easily

Promises are chainable (monadic, if you want):

  • If you need to transform the value that a promise represents, you map a transform function over the promise and get back a new promise that represents the transformed result. You cannot synchronously get the value to use it somehow, but you can easily lift the transformation in the promise context. No boilerplate callbacks.
  • If you want to chain two asynchronous tasks, you can use the .then() method. It will take a callback to be called with the first result, and returns a promise for the result of the promise that the callback returns.

Sounds complicated? Time for a code example.

var p1 = api1(); // returning a promise
var p3 = p1.then(function(api1Result) {
    var p2 = api2(); // returning a promise
    return p2; // The result of p2 …
}); // … becomes the result of p3

// So it does not make a difference whether you write
api1().then(function(api1Result) {
    return api2().then(console.log)
// or the flattened version
api1().then(function(api1Result) {
    return api2();

Flattening does not come magically, but you can easily do it. For your heavily nested example, the (near) equivalent would be

api1().then(api2).then(api3).then(/* do-work-callback */);

If seeing the code of these methods helps understanding, here's a most basic promise lib in a few lines.

What's the big fuss about promises?

The Promise abstraction allows much better composability of functions. For example, next to then for chaining, the all function creates a promise for the combined result of multiple parallel-waiting promises.

Last but not least Promises come with integrated error handling. The result of the computation might be that either the promise is fulfilled with a value, or it is rejected with a reason. All the composition functions handle this automatically and propagate errors in promise chains, so that you don't need to care about it explicitly everywhere - in contrast to a plain-callback implementation. In the end, you can add a dedicated error callback for all occurred exceptions.

Not to mention having to convert things to promises.

That's quite trivial actually with good promise libraries, see How do I convert an existing callback API to promises?

How to retrieve SQL result column value using column name in Python?

You didn't provide many details, but you could try something like this:

# conn is an ODBC connection to the DB
dbCursor = conn.cursor()
sql = ('select field1, field2 from table') 
dbCursor = conn.cursor()
for row in dbCursor:
    # Now you should be able to access the fields as properties of "row"
    myVar1 = row.field1
    myVar2 = row.field2

How can I make Java print quotes, like "Hello"?

Take note, there are a few certain things to take note when running backslashes with specific characters.


The output above will be:


System.out.println(" Hello\"  ");

The output above will be:


.gitignore all the .DS_Store files in every folder and subfolder

Step :1)Remove the existing files using this command

find . -name .DS_Store -print0 | xargs -0 git rm -f --ignore-unmatch

Step : 2)Add .DS_Store in your .gitignore file

Step :3) Commit your changes in .gitignore git add .gitignore git commit -m "removed .DS_Store"

Find all matches in workbook using Excel VBA

Based on Ahmed's answer, after some cleaning up and generalization, including the other "Find" parameters, so we can use this function in any situation:

'Uses Range.Find to get a range of all find results within a worksheet
' Same as Find All from search dialog box
Function FindAll(rng As Range, What As Variant, Optional LookIn As XlFindLookIn = xlValues, Optional LookAt As XlLookAt = xlWhole, Optional SearchOrder As XlSearchOrder = xlByColumns, Optional SearchDirection As XlSearchDirection = xlNext, Optional MatchCase As Boolean = False, Optional MatchByte As Boolean = False, Optional SearchFormat As Boolean = False) As Range
    Dim SearchResult As Range
    Dim firstMatch As String
    With rng
        Set SearchResult = .Find(What, , LookIn, LookAt, SearchOrder, SearchDirection, MatchCase, MatchByte, SearchFormat)
        If Not SearchResult Is Nothing Then
            firstMatch = SearchResult.Address
                If FindAll Is Nothing Then
                    Set FindAll = SearchResult
                    Set FindAll = Union(FindAll, SearchResult)
                End If
                Set SearchResult = .FindNext(SearchResult)
            Loop While Not SearchResult Is Nothing And SearchResult.Address <> firstMatch
        End If
    End With
End Function

Apache is not running from XAMPP Control Panel ( Error: Apache shutdown unexpectedly. This may be due to a blocked port)

If you are installed Skype, Please check this option.

enter image description here

Another case is Windows 10

Check this:

  1. Go to Start, type in services.msc
  2. Scroll down in the Services window to find the World Wide Web Publishing Service.
  3. Right-click on it, and select Stop or Disable it if you just want to use XAMPP only.

enter image description here

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required?

First check for gmail's security related issues. You may have enabled double authentication in gmail. Also check your gmail inbox if you are getting any security alerts. In such cases check other answer of @mjb as below

Below is the very general thing that i always check first for such issues

client.UseDefaultCredentials = true;

set it to false.

Note @Joe King's answer - you must set client.UseDefaultCredentials before you set client.Credentials

Reading large text files with streams in C#

If you read the performance and benchmark stats on this website, you'll see that the fastest way to read (because reading, writing, and processing are all different) a text file is the following snippet of code:

using (StreamReader sr = File.OpenText(fileName))
    string s = String.Empty;
    while ((s = sr.ReadLine()) != null)
        //do your stuff here

All up about 9 different methods were bench marked, but that one seem to come out ahead the majority of the time, even out performing the buffered reader as other readers have mentioned.

Change image onmouseover

Here is an example:

HTML code:

<img id="myImg" src=""/>

JavaScript code:

$(document).ready(function() {
    $( "#myImg" ).mouseover(function(){
        $(this).attr("src", "");

    $( "#myImg" ).mouseout(function(){
        $(this).attr("src", "");

Edit: Sorry, your code was a bit strange. Now I understood what you were doing. ;) The hover method is better, of course.

Javascript - validation, numbers only

The simplest solution.

Thanks to my partner that gave me this answer.

You can set an onkeypress event on the input textbox like this:


and then use regular expressions like this:

function validate(evt){
     evt.value = evt.value.replace(/[^0-9]/g,"");

It will scan and remove any letter or sign different from number in the field.

EnterKey to press button in VBA Userform

Further to @Penn's comment, and in case the link breaks, you can also achieve this by setting the Default property of the button to True (you can set this in the properties window, open by hitting F4)

That way whenever Return is hit, VBA knows to activate the button's click event. Similarly setting the Cancel property of a button to True would cause that button's click event to run whenever ESC key is hit (useful for gracefully exiting the Userform)

Source: Olivier Jacot-Descombes's answer accessible here

Detecting when a div's height changes using jQuery

This is how I recently handled this problem:

$('#your-resizing-div').bind('getheight', function() {

function your_function_to_load_content() {
    /*whatever your thing does*/

I know I'm a few years late to the party, just think my answer may help some people in the future, without having to download any plugins.

Regex to match any character including new lines

Yeap, you just need to make . match newline :

$string =~ /(START)(.+?)(END)/s;

Javascript switch vs. if...else if...else

Sometimes it's better to use neither. For example, in a "dispatch" situation, Javascript lets you do things in a completely different way:

function dispatch(funCode) {
  var map = {
    'explode': function() {
      if (flammable()) issueWarning();

    'hibernate': function() {
      if (status() == 'sleeping') return;
      // ... I can't keep making this stuff up
    // ...

  var thisFun = map[funCode];
  if (thisFun) thisFun();

Setting up multi-way branching by creating an object has a lot of advantages. You can add and remove functionality dynamically. You can create the dispatch table from data. You can examine it programmatically. You can build the handlers with other functions.

There's the added overhead of a function call to get to the equivalent of a "case", but the advantage (when there are lots of cases) of a hash lookup to find the function for a particular key.

Conversion failed when converting date and/or time from character string while inserting datetime

I had this issue when trying to concatenate getdate() into a string that I was inserting into an nvarchar field.

I did some casting to get around it:

    '<h2>111 Any St.<br />Anywhere, ST 11111</h2><br />' + 
        CAST(CAST(getdate() AS datetime2) AS nvarchar) + 
    '<br /><br /><br />'

That's a sanitized example. The key portion of that is:

...' + CAST(CAST(getdate() AS datetime2) AS nvarchar) + '...

Casted the date as datetime2, then as nvarchar to concatenate it.

Convert timestamp long to normal date format

I tried this and worked for me.

Date = (long)(DateTime.Now.Subtract(new DateTime(1970, 1, 1, 0, 0, 0))).TotalSeconds

How to free memory in Java?


Runs the garbage collector.

Calling the gc method suggests that the Java Virtual Machine expend effort toward recycling unused objects in order to make the memory they currently occupy available for quick reuse. When control returns from the method call, the Java Virtual Machine has made a best effort to reclaim space from all discarded objects.

Not recommended.

Edit: I wrote the original response in 2009. It's now 2015.

Garbage collectors have gotten steadily better in the ~20 years Java's been around. At this point, if you're manually calling the garbage collector, you may want to consider other approaches:

  • If you're forcing GC on a limited number of machines, it may be worth having a load balancer point away from the current machine, waiting for it to finish serving to connected clients, timeout after some period for hanging connections, and then just hard-restart the JVM. This is a terrible solution, but if you're looking at System.gc(), forced-restarts may be a possible stopgap.
  • Consider using a different garbage collector. For example, the (new in the last six years) G1 collector is a low-pause model; it uses more CPU overall, but does it's best to never force a hard-stop on execution. Since server CPUs now almost all have multiple cores, this is A Really Good Tradeoff to have available.
  • Look at your flags tuning memory use. Especially in newer versions of Java, if you don't have that many long-term running objects, consider bumping up the size of newgen in the heap. newgen (young) is where new objects are allocated. For a webserver, everything created for a request is put here, and if this space is too small, Java will spend extra time upgrading the objects to longer-lived memory, where they're more expensive to kill. (If newgen is slightly too small, you're going to pay for it.) For example, in G1:
    • XX:G1NewSizePercent (defaults to 5; probably doesn't matter.)
    • XX:G1MaxNewSizePercent (defaults to 60; probably raise this.)
  • Consider telling the garbage collector you're not okay with a longer pause. This will cause more-frequent GC runs, to allow the system to keep the rest of it's constraints. In G1:
    • XX:MaxGCPauseMillis (defaults to 200.)

Invalid Host Header when ngrok tries to connect to React dev server

Option 1

If you do not need to use Authentication you can add configs to ngrok commands

ngrok http 9000 --host-header=rewrite


ngrok http 9000 --host-header="localhost:9000"

But in this case Authentication will not work on your website because ngrok rewriting headers and session is not valid for your ngrok domain

Option 2

If you are using webpack you can add the following configuration

devServer: {
    disableHostCheck: true

In that case Authentication header will be valid for your ngrok domain

SQL state [99999]; error code [17004]; Invalid column type: 1111 With Spring SimpleJdbcCall

I think the problem is with the datatype of the data you are passing Caused by: java.sql.SQLException: Invalid column type: 1111 check the datatypes you pass with the actual column datatypes may be there can be some mismatch or some constraint violation with null

How can I get a List from some class properties with Java 8 Stream?

You can use map :

List<String> names =


In order to combine the Lists of friend names, you need to use flatMap :

List<String> friendNames =

Passing parameters to a JDBC PreparedStatement

The problem was that you needed to add " ' ;" at the end.

How to retrieve the current value of an oracle sequence without increment it?

If your use case is that some backend code inserts a record, then the same code wants to retrieve the last insert id, without counting on any underlying data access library preset function to do this, then, as mentioned by others, you should just craft your SQL query using SEQ_MY_NAME.NEXTVAL for the column you want (usually the primary key), then just run statement SELECT SEQ_MY_NAME.CURRVAL FROM dual from the backend.

Remember, CURRVAL is only callable if NEXTVAL has been priorly invoked, which is all naturally done in the strategy above...

How to revert a "git rm -r ."?


Since git rm . deletes all files in this and child directories in the working checkout as well as in the index, you need to undo each of these changes:

git reset HEAD . # This undoes the index changes
git checkout .   # This checks out files in this and child directories from the HEAD

This should do what you want. It does not affect parent folders of your checked-out code or index.

Old answer that wasn't:

reset HEAD

will do the trick, and will not erase any uncommitted changes you have made to your files.

after that you need to repeat any git add commands you had queued up.

jquery save json data object in cookie

use JSON.stringify(userData) to coverty json object to string.

var dataStore = $.cookie("basket-data", JSON.stringify($("#ArticlesHolder").data()));

and for getting back from cookie use JSON.parse()

var data=JSON.parse($.cookie("basket-data"))

How can I access Google Sheet spreadsheets only with Javascript?

You can read Google Sheets spreadsheets data in JavaScript by using the RGraph sheets connector:

Initially (a few years ago) this relied on some RGraph functions to work its magic - but now it can work standalone (ie not requiring the RGraph common library).

Some example code (this example makes an RGraph chart):

<!-- Include the sheets library -->
<script src="RGraph.common.sheets.js"></script>

<!-- Include these two RGraph libraries to make the chart -->
<script src="RGraph.common.key.js"></script>
<script src=""></script>

    // Create a new RGraph Sheets object using the spreadsheet's key and
    // the callback function that creates the chart. The RGraph.Sheets object is
    // passed to the callback function as an argument so it doesn't need to be
    // assigned to a variable when it's created
    new RGraph.Sheets('1ncvARBgXaDjzuca9i7Jyep6JTv9kms-bbIzyAxbaT0E', function (sheet)
        // Get the labels from the spreadsheet by retrieving part of the first row
        var labels = sheet.get('A2:A7');

        // Use the column headers (ie the names) as the key
        var key = sheet.get('B1:E1');

        // Get the data from the sheet as the data for the chart
        var data   = [
            sheet.get('B2:E2'), // January
            sheet.get('B3:E3'), // February
            sheet.get('B4:E4'), // March
            sheet.get('B5:E5'), // April
            sheet.get('B6:E6'), // May
            sheet.get('B7:E7')  // June

        // Create and configure the chart; using the information retrieved above
        // from the spreadsheet
        var bar = new RGraph.Bar({
            id: 'cvs',
            data: data,
            options: {
                backgroundGridVlines: false,
                backgroundGridBorder: false,
                xaxisLabels: labels,
                xaxisLabelsOffsety: 5,
                colors: ['#A8E6CF','#DCEDC1','#FFD3B6','#FFAAA5'],
                shadow: false,
                colorsStroke: 'rgba(0,0,0,0)',
                yaxis: false,
                marginLeft: 40,
                marginBottom: 35,
                marginRight: 40,
                key: key,
                keyBoxed: false,
                keyPosition: 'margin',
                keyTextSize: 12,
                textSize: 12,
                textAccessible: false,
                axesColor: '#aaa'

How can I get a list of all values in select box?





Link to fiddle

And I agree with Abraham - you might want to use text instead of value

The reason your fiddle didn't work was because you chose the option: "onLoad" instead of: "No wrap - in "

Redis command to get all available keys?

In order to get all the keys available in redis server, you should open redis-cli and type: KEYS * In order to get more help please visit this page: This Link

How do I make a simple crawler in PHP?

Hobodave you were very close. The only thing I have changed is within the if statement that checks to see if the href attribute of the found anchor tag begins with 'http'. Instead of simply adding the $url variable which would contain the page that was passed in you must first strip it down to the host which can be done using the parse_url php function.

function crawl_page($url, $depth = 5)
  static $seen = array();
  if (isset($seen[$url]) || $depth === 0) {

  $seen[$url] = true;

  $dom = new DOMDocument('1.0');

  $anchors = $dom->getElementsByTagName('a');
  foreach ($anchors as $element) {
    $href = $element->getAttribute('href');
    if (0 !== strpos($href, 'http')) {
       /* this is where I changed hobodave's code */
        $host = "http://".parse_url($url,PHP_URL_HOST);
        $href = $host. '/' . ltrim($href, '/');
    crawl_page($href, $depth - 1);

  echo "New Page:<br /> ";
  echo "URL:",$url,PHP_EOL,"<br />","CONTENT:",PHP_EOL,$dom->saveHTML(),PHP_EOL,PHP_EOL,"  <br /><br />";

crawl_page("", 5);

How to get these two divs side-by-side?

User float:left property in child div class

check for div structure in detail :

Gnuplot line types

Until version 4.6

The dash type of a linestyle is given by the linetype, which does also select the line color unless you explicitely set an other one with linecolor.

However, the support for dashed lines depends on the selected terminal:

  1. Some terminals don't support dashed lines, like png (uses libgd)
  2. Other terminals, like pngcairo, support dashed lines, but it is disables by default. To enable it, use set termoption dashed, or set terminal pngcairo dashed ....
  3. The exact dash patterns differ between terminals. To see the defined linetype, use the test command:


set terminal pngcairo dashed
set output 'test.png'
set output


enter image description here

whereas, the postscript terminal shows different dash patterns:

set terminal postscript eps color colortext
set output 'test.eps'
set output

enter image description here

Version 5.0

Starting with version 5.0 the following changes related to linetypes, dash patterns and line colors are introduced:

  • A new dashtype parameter was introduced:

    To get the predefined dash patterns, use e.g.

    plot x dashtype 2

    You can also specify custom dash patterns like

    plot x dashtype (3,5,10,5),\
         2*x dashtype '.-_'
  • The terminal options dashed and solid are ignored. By default all lines are solid. To change them to dashed, use e.g.

    set for [i=1:8] linetype i dashtype i
  • The default set of line colors was changed. You can select between three different color sets with set colorsequence default|podo|classic:

enter image description here

Why do we need middleware for async flow in Redux?

The short answer: seems like a totally reasonable approach to the asynchrony problem to me. With a couple caveats.

I had a very similar line of thought when working on a new project we just started at my job. I was a big fan of vanilla Redux's elegant system for updating the store and rerendering components in a way that stays out of the guts of a React component tree. It seemed weird to me to hook into that elegant dispatch mechanism to handle asynchrony.

I ended up going with a really similar approach to what you have there in a library I factored out of our project, which we called react-redux-controller.

I ended up not going with the exact approach you have above for a couple reasons:

  1. The way you have it written, those dispatching functions don't have access to the store. You can somewhat get around that by having your UI components pass in all of the info the dispatching function needs. But I'd argue that this couples those UI components to the dispatching logic unnecessarily. And more problematically, there's no obvious way for the dispatching function to access updated state in async continuations.
  2. The dispatching functions have access to dispatch itself via lexical scope. This limits the options for refactoring once that connect statement gets out of hand -- and it's looking pretty unwieldy with just that one update method. So you need some system for letting you compose those dispatcher functions if you break them up into separate modules.

Take together, you have to rig up some system to allow dispatch and the store to be injected into your dispatching functions, along with the parameters of the event. I know of three reasonable approaches to this dependency injection:

  • redux-thunk does this in a functional way, by passing them into your thunks (making them not exactly thunks at all, by dome definitions). I haven't worked with the other dispatch middleware approaches, but I assume they're basically the same.
  • react-redux-controller does this with a coroutine. As a bonus, it also gives you access to the "selectors", which are the functions you may have passed in as the first argument to connect, rather than having to work directly with the raw, normalized store.
  • You could also do it the object-oriented way by injecting them into the this context, through a variety of possible mechanisms.


It occurs to me that part of this conundrum is a limitation of react-redux. The first argument to connect gets a state snapshot, but not dispatch. The second argument gets dispatch but not the state. Neither argument gets a thunk that closes over the current state, for being able to see updated state at the time of a continuation/callback.

Remove NaN from pandas series

A small usage of np.nan ! = np.nan

0    1.0
1    2.0
2    3.0
3    4.0
5    5.0
dtype: float64

More Info

np.nan == np.nan
Out[954]: False

Parse error: syntax error, unexpected T_ECHO in

Missing ; after var_dump($row)

Writing JSON object to a JSON file with fs.writeFileSync

You need to stringify the object.

fs.writeFileSync('../data/phraseFreqs.json', JSON.stringify(output));

Android : Capturing HTTP Requests with non-rooted android device

Set a as proxy on a same LAN

  • Open Source
  • Built in python 3
  • Installable via pip

PDO closing connection

According to documentation you're correct (

The connection remains active for the lifetime of that PDO object. To close the connection, you need to destroy the object by ensuring that all remaining references to it are deleted--you do this by assigning NULL to the variable that holds the object. If you don't do this explicitly, PHP will automatically close the connection when your script ends.

Note that if you initialise the PDO object as a persistent connection it will not automatically close the connection.

Telling gcc directly to link a library statically

It is possible of course, use -l: instead of -l. For example -l:libXYZ.a to link with libXYZ.a. Notice the lib written out, as opposed to -lXYZ which would auto expand to libXYZ.

How to use ADB Shell when Multiple Devices are connected? Fails with "error: more than one device and emulator"

To install an apk on one of your emulators:

First get the list of devices:

-> adb devices
List of devices attached
25sdfsfb3801745eg        device
emulator-0954   device

Then install the apk on your emulator with the -s flag:

-> adb -s "25sdfsfb3801745eg" install "C:\Users\joel.joel\Downloads\release.apk"
Performing Streamed Install

Ps.: the order here matters, so -s <id> has to come before install command, otherwise it won't work.

Hope this helps someone!

Batch files: List all files in a directory with relative paths

You could simply get the character length of the current directory, and remove them from your absolute list

setlocal EnableDelayedExpansion
for /L %%n in (1 1 500) do if "!__cd__:~%%n,1!" neq "" set /a "len=%%n+1"
setlocal DisableDelayedExpansion
for /r . %%g in (*.log) do (
  set "absPath=%%g"
  setlocal EnableDelayedExpansion
  set "relPath=!absPath:~%len%!"

Difference between hamiltonian path and euler path

Eulerian path must visit each edge exactly once, while Hamiltonian path must visit each vertex exactly once.

How to do case insensitive string comparison?

I like this quick shorthand variation -

export const equalsIgnoreCase = (str1, str2) => {
    return (!str1 && !str2) || (str1 && str2 && str1.toUpperCase() == str2.toUpperCase())

Quick in processing, and does what it is intended to.

make sounds (beep) with c++

There are a few OS-specific routines for beeping.

  • On a Unix-like OS, try the (n)curses beep() function. This is likely to be more portable than writing '\a' as others have suggested, although for most terminal emulators that will probably work.

  • In some *BSDs there is a PC speaker device. Reading the driver source, the SPKRTONE ioctl seems to correspond to the raw hardware interface, but there also seems to be a high-level language built around write()-ing strings to the driver, described in the manpage.

  • It looks like Linux has a similar driver (see this article for example; there is also some example code on this page if you scroll down a bit.).

  • In Windows there is a function called Beep().

What’s the best RESTful method to return total number of items in an object?

Seems easiest to just add a


and return the total count of members

How to create temp table using Create statement in SQL Server?

A temporary table can have 3 kinds, the # is the most used. This is a temp table that only exists in the current session. An equivalent of this is @, a declared table variable. This has a little less "functions" (like indexes etc) and is also only used for the current session. The ## is one that is the same as the #, however, the scope is wider, so you can use it within the same session, within other stored procedures.

You can create a temp table in various ways:

declare @table table (id int)
create table #table (id int)
create table ##table (id int)
select * into #table from xyz

How can I adjust DIV width to contents

Try width: max-content to adjust the width of the div by it's content.

<!DOCTYPE html>
div.ex1 {
  margin: auto;
  border: 3px solid #73AD21;

div.ex2 {
  width: max-content;
  margin: auto;
  border: 3px solid #73AD21;

<div class="ex1">This div element has width 500px;</div>
<div class="ex2">Width by content size</div>


Convert date formats in bash

If you would like a bash function that works both on Mac OS X and Linux:

# Convert one date format to another
# Usage: convert_date_format <input_format> <date> <output_format>
# Example: convert_date_format '%b %d %T %Y %Z' 'Dec 10 17:30:05 2017 GMT' '%Y-%m-%d'
convert_date_format() {
  local INPUT_FORMAT="$1"
  local INPUT_DATE="$2"
  local OUTPUT_FORMAT="$3"
  local UNAME=$(uname)

  if [[ "$UNAME" == "Darwin" ]]; then
    # Mac OS X
  elif [[ "$UNAME" == "Linux" ]]; then
    # Linux
    date -d "$INPUT_DATE" +"$OUTPUT_FORMAT"
    # Unsupported system
    echo "Unsupported system"

# Example: 'Dec 10 17:30:05 2017 GMT' => '2017-12-10'
convert_date_format '%b %d %T %Y %Z' 'Dec 10 17:30:05 2017 GMT' '%Y-%m-%d'

Why is C so fast, and why aren't other languages as fast or faster?

I know plenty of people have said it in a long winded way, but:

C is faster because it does less (for you).

How to perform a for loop on each character in a string in Bash?

The C style loop in @chepner's answer is in the shell function update_terminal_cwd, and the grep -o . solution is clever, but I was surprised not to see a solution using seq. Here's mine:

read word
for i in $(seq 1 ${#word}); do
  echo "${word:i-1:1}"

How do you stylize a font in Swift?


Label.Font = UIFont.FromName("Copperplate", 10.0f);


text.font = UIFont.init(name: "Poppins-Regular", size: 14)

To get the list of font family Github/IOS-UIFont-Names

Install MySQL on Ubuntu without a password prompt

This should do the trick

export DEBIAN_FRONTEND=noninteractive
sudo -E apt-get -q -y install mysql-server

Of course, it leaves you with a blank root password - so you'll want to run something like

mysqladmin -u root password mysecretpasswordgoeshere

Afterwards to add a password to the account.

docker command not found even though installed with apt-get


For Ubuntu 14.04/16.04/16.10/17.04:

sudo add-apt-repository "deb [arch=amd64] \ $(lsb_release -cs) stable"

For Ubuntu 17.10:

sudo add-apt-repository "deb [arch=amd64] zesty stable"

Add Docker’s official GPG key:

$ curl -fsSL | sudo apt-key add -

Then install

$ sudo apt-get update && sudo apt-get -y install docker-ce

How to find NSDocumentDirectory in Swift?

Xcode 8b4 Swift 3.0

let paths = NSSearchPathForDirectoriesInDomains(FileManager.SearchPathDirectory.documentDirectory, FileManager.SearchPathDomainMask.userDomainMask, true)

Is there a maximum number you can set Xmx to when trying to increase jvm memory?

I think a 32 bit JVM has a maximum of 2GB memory.This might be out of date though. If I understood correctly, you set the -Xmx on Eclipse launcher. If you want to increase the memory for the program you run from Eclipse, you should define -Xmx in the "Run->Run configurations..."(select your class and open the Arguments tab put it in the VM arguments area) menu, and NOT on Eclipse startup

Edit: details you asked for. in Eclipse 3.4

  1. Run->Run Configurations...

  2. if your class is not listed in the list on the left in the "Java Application" subtree, click on "New Launch configuration" in the upper left corner

  3. on the right, "Main" tab make sure the project and the class are the right ones

  4. select the "Arguments" tab on the right. this one has two text areas. one is for the program arguments that get in to the args[] array supplied to your main method. the other one is for the VM arguments. put into the one with the VM arguments(lower one iirc) the following:

    I think that 1024m should more than enough for what you need though!

  5. Click Apply, then Click Run

  6. Should work :)

Get JSON Data from URL Using Android?

I feel your frustration.

Android is crazy fragmented, and the the sheer amount of different examples on the web when searching is not helping.

That said, I just completed a sample partly based on mustafasevgi sample, partly built from several other stackoverflow answers, I try to achieve this functionality, in the most simplistic way possible, I feel this is close to the goal.

(Mind you, code should be easy to read and tweak, so it does not fit your json object perfectly, but should be super easy to edit, to fit any scenario)

protected class yourDataTask extends AsyncTask<Void, Void, JSONObject>
    protected JSONObject doInBackground(Void... params)

        String str="";
        URLConnection urlConn = null;
        BufferedReader bufferedReader = null;
            URL url = new URL(str);
            urlConn = url.openConnection();
            bufferedReader = new BufferedReader(new InputStreamReader(urlConn.getInputStream()));

            StringBuffer stringBuffer = new StringBuffer();
            String line;
            while ((line = bufferedReader.readLine()) != null)

            return new JSONObject(stringBuffer.toString());
        catch(Exception ex)
            Log.e("App", "yourDataTask", ex);
            return null;
            if(bufferedReader != null)
                try {
                } catch (IOException e) {

    protected void onPostExecute(JSONObject response)
        if(response != null)
            try {
                Log.e("App", "Success: " + response.getString("yourJsonElement") );
            } catch (JSONException ex) {
                Log.e("App", "Failure", ex);

This would be the json object it is targeted towards.

    "yourJsonElement":"Hi, I'm a string",
    "anotherElement":"Ohh, why didn't you pick me"

It is working on my end, hope this is helpful to someone else out there.

Oracle DB: How can I write query ignoring case?

Use ALTER SESSION statements to set comparison to case-insensitive:

alter session set NLS_COMP=LINGUISTIC;
alter session set NLS_SORT=BINARY_CI;

If you're still using version 10gR2, use the below statements. See this FAQ for details.

alter session set NLS_COMP=ANSI;
alter session set NLS_SORT=BINARY_CI;

Static method in a generic class?

It is correctly mentioned in the error: you cannot make a static reference to non-static type T. The reason is the type parameter T can be replaced by any of the type argument e.g. Clazz<String> or Clazz<integer> etc. But static fields/methods are shared by all non-static objects of the class.

The following excerpt is taken from the doc:

A class's static field is a class-level variable shared by all non-static objects of the class. Hence, static fields of type parameters are not allowed. Consider the following class:

public class MobileDevice<T> {
    private static T os;

    // ...

If static fields of type parameters were allowed, then the following code would be confused:

MobileDevice<Smartphone> phone = new MobileDevice<>();
MobileDevice<Pager> pager = new MobileDevice<>();
MobileDevice<TabletPC> pc = new MobileDevice<>();

Because the static field os is shared by phone, pager, and pc, what is the actual type of os? It cannot be Smartphone, Pager, and TabletPC at the same time. You cannot, therefore, create static fields of type parameters.

As rightly pointed out by chris in his answer you need to use type parameter with the method and not with the class in this case. You can write it like:

static <E> void doIt(E object) 

Docker container will automatically stop after "docker run -d"

According to this answer, adding the -t flag will prevent the container from exiting when running in the background. You can then use docker exec -i -t <image> /bin/bash to get into a shell prompt.

docker run -t -d <image> <command>

It seems that the -t option isn't documented very well, though the help says that it "allocates a pseudo-TTY."

calling a java servlet from javascript

Sorry, I read jsp not javascript. You need to do something like (note that this is a relative url and may be different depending on the url of the document this javascript is in):

document.location = 'path/to/servlet';

Where your servlet-mapping in web.xml looks something like this:


How to include "zero" / "0" results in COUNT aggregate?

USE join to get 0 count in the result using GROUP BY.

simply 'join' does Inner join in MS SQL so , Go for left or right join.

If the table which contains the primary key is mentioned first in the QUERY then use LEFT join else RIGHT join.


select WARDNO,count(WARDCODE) from MAIPADH 
group by WARDNO


select WARDNO,count(WARDCODE) from MSWARDH

Take group by from the table which has Primary key and count from the another table which has actual entries/details.

How to flip background image using CSS?

According to w3schools:

The transform property is supported in Internet Explorer 10, Firefox, and Opera. Internet Explorer 9 supports an alternative, the -ms-transform property (2D transforms only). Safari and Chrome support an alternative, the -webkit-transform property (3D and 2D transforms). Opera supports 2D transforms only.

This is a 2D transform, so it should work, with the vendor prefixes, on Chrome, Firefox, Opera, Safari, and IE9+.

Other answers used :before to stop it from flipping the inner content. I used this on my footer (to vertically-mirror the image from my header):


<p><a href="page">Footer Link</a></p>
<p>&copy; 2014 Company</p>


footer {
background:url(/img/headerbg.png) repeat-x 0 0;

/* flip background vertically */

/* undo the vertical flip for all child elements */
footer * {

So you end up flipping the element and then re-flipping all its children. Works with nested elements, too.

How can I find out if I have Xcode commandline tools installed?

For macOS catalina try this : open Xcode. if not existing. download from App store (about 11GB) then open Xcode>open developer tool>more developer tool and used my apple id to download a compatible command line tool. Then, after downloading, I opened Xcode>Preferences>Locations>Command Line Tool and selected the newly downloaded command line tool from downloads.

Cannot find vcvarsall.bat when running a Python script

In case anyone comes here looking for an answer for Python 3.5; you need Visual Studio 2015.

Get Visual Studio 2015 Community here:, this worked for me with no further steps needed.

Many thanks to Ionel, apparently the only place on the web to find this information!

Xcode - How to fix 'NSUnknownKeyException', reason: … this class is not key value coding-compliant for the key X" error?

I found another possibility that may cause the issue.

When using "initWithNibName" method with the wrong xib name, it will lead to this kind of crash too.

Such as you choose to change a xib file's name, and then foget to change the name used in "initWithNibName" method to the same name.

Add User to Role ASP.NET Identity

I found good answer here Adding Role dynamically in new VS 2013 Identity UserManager

But in case to provide an example so you can check it I am gonna share some default code.

First make sure you have Roles inserted.

enter image description here

And second test it on user register method.

public async Task<ActionResult> Register(RegisterViewModel model)
    if (ModelState.IsValid)
        var user = new ApplicationUser() { UserName = model.UserName  };

        var result = await UserManager.CreateAsync(user, model.Password);
        if (result.Succeeded)
            var currentUser = UserManager.FindByName(user.UserName); 

            var roleresult = UserManager.AddToRole(currentUser.Id, "Superusers");

            await SignInAsync(user, isPersistent: false);
            return RedirectToAction("Index", "Home");

    // If we got this far, something failed, redisplay form
    return View(model);

And finally you have to get "Superusers" from the Roles Dropdown List somehow.

how to get current datetime in SQL?

  1. GETDATE() or GETUTCDATE() are now superseded by the richer SYSDATETIME, SYSUTCDATETIME, and SYSDATETIMEOFFSET (in SQL 2008)
  2. Yes, I don't think ANSI has ever declared anything, and so each manufacturer has their own.
  3. That would be NOW()

Hope this helps...