Programs & Examples On #Mysql proxy

MySQL Proxy is a simple program that sits between the client and MySQL server that can monitor, analyze or transform their communication. It is used mainly for load balancing, failover and query analysis.

Concatenating date with a string in Excel

Don't know if it's the best way but I'd do this:

=A1 & TEXT(A2,"mm/dd/yyyy")

That should format your date into your desired string.

Edit: That funny number you saw is the number of days between December 31st 1899 and your date. That's how Excel stores dates.

printing out a 2-D array in Matrix format

To properly format numbers in columns, it's best to use printf. Depending on how big are the max or min numbers, you might want to adjust the pattern "%4d". For instance to allow any integer between Integer.MIN_VALUE and Integer.MAX_VALUE, use "%12d".

public void printMatrix(int[][] matrix) {
    for (int row = 0; row < matrix.length; row++) {
        for (int col = 0; col < matrix[row].length; col++) {
            System.out.printf("%4d", matrix[row][col]);
        }
        System.out.println();
    }
}

Example output:

 36 913 888 908
732 626  61 237
  5   8  50 265
192 232 129 307

Image Processing: Algorithm Improvement for 'Coca-Cola Can' Recognition

There are a bunch of color descriptors used to recognise objects, the paper below compares a lot of them. They are specially powerful when combined with SIFT or SURF. SURF or SIFT alone are not very useful in a coca cola can image because they don't recognise a lot of interest points, you need the color information to help. I use BIC (Border/Interior Pixel Classi?cation) with SURF in a project and it worked great to recognise objects.

Color descriptors for Web image retrieval: a comparative study

jQueryUI modal dialog does not show close button (x)

I had this problem and was able to resolve it with the declaration below.

$.fn.bootstrapBtn = $.fn.button.noConflict();

Set Background color programmatically

If you just want to use some of the predefined Android colors, you can use Color.COLOR (where COLOR is BLACK, WHITE, RED, etc.):

myView.setBackgroundColor(Color.GREEN);

Otherwise you can do as others have suggested with

myView.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.myCustomGreen));

I don't recommend using a hex color directly. You should keep all of your custom colors in colors.xml.

Use NSInteger as array index

According to the error message, you declared myLoc as a pointer to an NSInteger (NSInteger *myLoc) rather than an actual NSInteger (NSInteger myLoc). It needs to be the latter.

How to indent/format a selection of code in Visual Studio Code with Ctrl + Shift + F

I want to indent a specific section of code in Visual Studio Code:

  • Select the lines you want to indent, and
  • use Ctrl + ] to indent them.

If you want to format a section (instead of indent it):

  • Select the lines you want to format,
  • use Ctrl + K, Ctrl + F to format them.

Get an image extension from an uploaded file in Laravel

return $picName = time().'.'.$request->file->extension();

The time() function will make the image unique then the .$request->file->extension() gets the image extension for you.

You can use this it works well with Laravel 6 and above.

Adding one day to a date

<?php

function plusTimetoOldtime($Old_Time,$getFormat,$Plus_Time) {
    return date($getFormat,strtotime(date($getFormat,$Old_Time).$Plus_Time));
}

$Old_Time = strtotime("now");
$Plus_Time = '+1 day';
$getFormat = 'Y-m-d H:i:s';

echo plusTimetoOldtime($Old_Time,$getFormat,$Plus_Time);

?>

How can I rollback an UPDATE query in SQL server 2005?

You can rollback the statements you've executed within a transaction. Instead of commiting the transaction, rollback the transaction.

If you have updated something and want to rollback those updates, and you haven't done this inside a (not-yet-commited) transaction, then I think it's though luck ...

(Manually repair, or, restore backups)

Can you append strings to variables in PHP?

This is because PHP uses the period character . for string concatenation, not the plus character +. Therefore to append to a string you want to use the .= operator:

for ($i=1;$i<=100;$i++)
{
    $selectBox .= '<option value="' . $i . '">' . $i . '</option>';
}
$selectBox .= '</select>';

How do you create a temporary table in an Oracle database?

CREATE GLOBAL TEMPORARY TABLE Table_name
    (startdate DATE,
     enddate DATE,
     class CHAR(20))
  ON COMMIT DELETE ROWS;

Identifier not found error on function call

Unlike other languages you may be used to, everything in C++ has to be declared before it can be used. The compiler will read your source file from top to bottom, so when it gets to the call to swapCase, it doesn't know what it is so you get an error. You can declare your function ahead of main with a line like this:

void swapCase(char *name);

or you can simply move the entirety of that function ahead of main in the file. Don't worry about having the seemingly most important function (main) at the bottom of the file. It is very common in C or C++ to do that.

Where does error CS0433 "Type 'X' already exists in both A.dll and B.dll " come from?

This may happen when the same classname is specified in multiple .aspx.cs files, i.e. when two pages are created with different file name but by mistake have the same classname.

// file a.aspx
public partial class Test1: System.Web.UI.Page

// file b.aspx
public partial class Test1: System.Web.UI.Page

While building the webapplication this gives a warning, but the application runs, however, after publishing the application doesn't work anymore and throws the exception as mentioned in the OP's question.

Making sure that two classnames do no overlap solves the issue.

Facebook Like-Button - hide count?

The Like button coded to show "Recommend" is 84px wide and the "Like" button is 44px, will save some time for you CSS guys like me who need to hide how unpopular my page currently is! I put this code on top of my homepage, so initially I don't want it to advertise how few Likes I have.

Take a list of numbers and return the average

Simple math..

def average(n):
    result = 0
    for i in n:
      result += i
      ave_num = result / len(n)
    return ave_num

input -> [1,2,3,4,5]
output -> 3.0

Simple two column html layout without using tables

Well, you can do css tables instead of html tables. This keeps your html semantically correct, but allows you to use tables for layout purposes.

This seems to make more sense than using float hacks.

<html>
  <head>
    <style>

#content-wrapper{
  display:table;
}

#content{
  display:table-row;
}

#content>div{
  display:table-cell
}

/*adding some extras for demo purposes*/
#content-wrapper{
  width:100%;
  height:100%;
  top:0px;
  left:0px;
  position:absolute;
}
#nav{
  width:100px;
  background:yellow;
}
#body{
  background:blue;
}
</style>

  </head>
  <body>
    <div id="content-wrapper">
      <div id="content">
        <div id="nav">
          Left hand content
        </div>
        <div id="body">
          Right hand content
        </div>
      </div>
    </div>
  </body>
</html>

PHP Fatal error: Call to undefined function json_decode()

The module was install but symbolic link was not in /etc/php5/cli/conf.d

How to change heatmap.2 color range in R?

You could try to create your own color palette using the RColorBrewer package

my_palette <- colorRampPalette(c("green", "black", "red"))(n = 1000)

and see how this looks like. But I assume in your case only scaling would help if you really want to keep the black in "the middle". You can simply use my_palette instead of the redgreen()

I recommend that you check out the RColorBrewer package, they have pretty nice in-built palettes, and see interactive website for colorbrewer.

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

Export:

mysqldump --user=root databasename > whole.database.sql
mysqldump --user=root databasename onlySingleTableName > single.table.sql

Import:

Whole database:

mysql --user=root wholedatabase < whole.database.sql

Single table:

mysql --user=root databasename < single.table.sql

When doing a MERGE in Oracle SQL, how can I update rows that aren't matched in the SOURCE?

MERGE INTO target
USING
(
    --Source data
    SELECT id, some_value, 0 deleteMe FROM source
    --And anything that has been deleted from the source
    UNION ALL
    SELECT id, null some_value, 1 deleteMe
    FROM
    (
        SELECT id FROM target
        MINUS
        SELECT id FROM source
    )
) source
   ON (target.ID = source.ID)
WHEN MATCHED THEN
    --Requires a lot of ugly CASE statements, to prevent updating deleted data
    UPDATE SET target.some_value =
        CASE WHEN deleteMe=1 THEN target.some_value ELSE source.some_value end
    ,isDeleted = deleteMe
WHEN NOT MATCHED THEN
    INSERT (id, some_value, isDeleted) VALUES (source.id, source.some_value, 0)

--Test data
create table target as
select 1 ID, 'old value 1' some_value, 0 isDeleted from dual union all
select 2 ID, 'old value 2' some_value, 0 isDeleted from dual;

create table source as
select 1 ID, 'new value 1' some_value, 0 isDeleted from dual union all
select 3 ID, 'new value 3' some_value, 0 isDeleted from dual;


--Results:
select * from target;

ID  SOME_VALUE   ISDELETED
1   new value 1  0
2   old value 2  1
3   new value 3  0

Why is Ant giving me a Unsupported major.minor version error

The runtime jre was set to jre 6 instead of jre 7 in the build configuration window.

android - save image into gallery

I come here with the same doubt but for Xamarin for Android, I have used the Sigrist answer to do this method after save my file:

private void UpdateGallery()
{
    Intent mediaScanIntent = new Intent(Intent.ActionMediaScannerScanFile);
    Java.IO.File file = new Java.IO.File(_path);
    Android.Net.Uri contentUri = Android.Net.Uri.FromFile(file);
    mediaScanIntent.SetData(contentUri);
    Application.Context.SendBroadcast(mediaScanIntent);
} 

and it solved my problem, Thx Sigrist. I put it here becouse i did not found an answare about this for Xamarin and i hope it can help other people.

Node.js: Gzip compression?

As of today, epxress.compress() seems to be doing a brilliant job of this.

In any express app just call this.use(express.compress());.

I'm running locomotive on top of express personally and this is working beautifully. I can't speak to any other libraries or frameworks built on top of express but as long as they honor full stack transparency you should be fine.

CMAKE_MAKE_PROGRAM not found

Recently i had the same problem (Compiling OpenCV with CMake and Qt/MinGW on WIN764)

And I think I solve this including on my environment variable PATH (through Control Panel\All Control Panel Items\System\Advanced Sytem Settings) with the %MINGW_DIR%\bin and %CMAKE_DIR%/bin

Furthermore, I installed cmake2.8 on an easy directory (without blanks on it)

Error : java.lang.NoSuchMethodError: org.objectweb.asm.ClassWriter.<init>(I)V

You have an incompatibility between the version of ASM required by Hibernate (asm-1.5.3.jar) and the one required by Spring. But, actually, I wonder why you have asm-2.2.3.jar on your classpath (ASM is bundled in spring.jar and spring-core.jar to avoid such problems AFAIK). See HHH-2222.

Rename computer and join to domain in one step with PowerShell

Rename-Computer was removed from CTP3 because there are a lot of things done when renaming a computer and MS either didn't want to recreate that process or couldn't include all of the necessary bits. I think Jefferey Snover said to just use netdom.exe instead, as that is the best practice for renaming a computer on the command-line. Not the answer you were looking for, but should point you in the right direction

Java - How to create new Entry (key, value)

Why Map.Entry? I guess something like a key-value pair is fit for the case.

Use java.util.AbstractMap.SimpleImmutableEntry or java.util.AbstractMap.SimpleEntry

Evaluate expression given as a string

Sorry but I don't understand why too many people even think a string was something that could be evaluated. You must change your mindset, really. Forget all connections between strings on one side and expressions, calls, evaluation on the other side.

The (possibly) only connection is via parse(text = ....) and all good R programmers should know that this is rarely an efficient or safe means to construct expressions (or calls). Rather learn more about substitute(), quote(), and possibly the power of using do.call(substitute, ......).

fortunes::fortune("answer is parse")
# If the answer is parse() you should usually rethink the question.
#    -- Thomas Lumley
#       R-help (February 2005)

Dec.2017: Ok, here is an example (in comments, there's no nice formatting):

q5 <- quote(5+5)
str(q5)
# language 5 + 5

e5 <- expression(5+5)
str(e5)
# expression(5 + 5)

and if you get more experienced you'll learn that q5 is a "call" whereas e5 is an "expression", and even that e5[[1]] is identical to q5:

identical(q5, e5[[1]])
# [1] TRUE

Get difference between two lists

We can calculate intersection minus union of lists:

temp1 = ['One', 'Two', 'Three', 'Four']
temp2 = ['One', 'Two', 'Five']

set(temp1+temp2)-(set(temp1)&set(temp2))

Out: set(['Four', 'Five', 'Three']) 

Named colors in matplotlib

To get a full list of colors to use in plots:

import matplotlib.colors as colors
colors_list = list(colors._colors_full_map.values())

So, you can use in that way quickly:

scatter(X,Y, color=colors_list[0])
scatter(X,Y, color=colors_list[1])
scatter(X,Y, color=colors_list[2])
...
scatter(X,Y, color=colors_list[-1])

Mapping US zip code to time zone

There's actually a great Google API for this. It takes in a location and returns the timezone for that location. Should be simple enough to create a bash or python script to get the results for each address in a CSV file or database then save the timezone information.

https://developers.google.com/maps/documentation/timezone/start

Request Endpoint:

https://maps.googleapis.com/maps/api/timezone/json?location=38.908133,-77.047119&timestamp=1458000000&key=YOUR_API_KEY

Response:

{
   "dstOffset" : 3600,
   "rawOffset" : -18000,
   "status" : "OK",
   "timeZoneId" : "America/New_York",
   "timeZoneName" : "Eastern Daylight Time"
}

Pretty git branch graphs

I have this git log alias in ~/.gitconfig to view the graph history:

[alias]
l = log --all --graph --pretty=format:'%C(auto)%h%C(auto)%d %s %C(dim white)(%aN, %ar)'

With this in place, git l will output something like:

enter image description here

In Git 2.12+ you can even customize the line colors of the graph using the log.graphColors configuration option.

As for the logs' format, it's similar to --oneline, with the addition of the author name (respecting .mailmap) and the relative author date. Note that the %C(auto) syntax, which tells Git to use the default colors for commit hash, etc. is supported in Git >= 1.8.3.

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

For Windows, first install the git base from here: https://git-scm.com/downloads

Next, set the environment variable:

  1. Press Windows+R and type sysdm.cpl
  2. Select advance -> Environment variable
  3. Select path-> edit the path and paste the below line:
C:\Program Files\Git\git-bash.exe

To test it, open the command window: press Windows+R, type cmd and then type ssh.

Repeat a string in JavaScript a number of times

Array(10).fill('a').join('')

Although the most voted answer is a bit more compact, with this approach you don't have to add an extra array item.

Space between two rows in a table?

Have you tried:

tr.classname { margin-bottom:5em; }

Alternatively, each td can be adjusted as well:

td.classname { margin-bottom:5em; }

or

 td.classname { padding-bottom:5em; }

Check if value exists in enum in TypeScript

Type assertion is un-avoidable. Following up on

enum Vehicle {
    Car = 'car',
    Bike = 'bike',
    Truck = 'truck'
}

I found one alternative that wasn't mentioned so thought I'd share my fix for it:

const someString: Vehicle | string = 'car';
const inEnum = (Object.values(Vehicle) as string[]).includes(someString);

I find this more truthful because we usually come in typesafe(with a string) and want to compare it to the enum; it'd be a bit reckless to typecast it to any(reason: never do this) or Vehicle(reason: likely untruthful). Instead, typecasting the Object.values() output to an array of strings is in-fact very much real.

Why does ANT tell me that JAVA_HOME is wrong when it is not?

It's also possible that you have included /bin in your JAVA_HOME setting, and Ant is adding /bin to it - thereby not finding any exe's. It's happened to me :}

How to get the path of current worksheet in VBA?

Use Application.ActiveWorkbook.Path for just the path itself (without the workbook name) or Application.ActiveWorkbook.FullName for the path with the workbook name.

Django Model() vs Model.objects.create()

The two syntaxes are not equivalent and it can lead to unexpected errors. Here is a simple example showing the differences. If you have a model:

from django.db import models

class Test(models.Model):

    added = models.DateTimeField(auto_now_add=True)

And you create a first object:

foo = Test.objects.create(pk=1)

Then you try to create an object with the same primary key:

foo_duplicate = Test.objects.create(pk=1)
# returns the error:
# django.db.utils.IntegrityError: (1062, "Duplicate entry '1' for key 'PRIMARY'")

foo_duplicate = Test(pk=1).save()
# returns the error:
# django.db.utils.IntegrityError: (1048, "Column 'added' cannot be null")

Should CSS always preceed Javascript?

Updated 2017-12-16

I was not sure about the tests in OP. I decided to experiment a little and ended up busting some of the myths.

Synchronous <script src...> will block downloading of the resources below it until it is downloaded and executed

This is no longer true. Have a look at the waterfall generated by Chrome 63:

<head>
<script src="//alias-0.redacted.com/payload.php?type=js&amp;delay=333&amp;rand=1"></script>
<script src="//alias-1.redacted.com/payload.php?type=js&amp;delay=333&amp;rand=2"></script>
<script src="//alias-2.redacted.com/payload.php?type=js&amp;delay=333&amp;rand=3"></script>
</head>

Chrome net inspector -> waterfall

<link rel=stylesheet> will not block download and execution of scripts below it

This is incorrect. The stylesheet will not block download but it will block execution of the script (little explanation here). Have a look at performance chart generated by Chrome 63:

<link href="//alias-0.redacted.com/payload.php?type=css&amp;delay=666" rel="stylesheet">
<script src="//alias-1.redacted.com/payload.php?type=js&amp;delay=333&amp;block=1000"></script>

Chrome dev tools -> performance


Keeping the above in mind, the results in OP can be explained as follows:

CSS First:

CSS Download  500ms:<------------------------------------------------>
JS Download   400ms:<-------------------------------------->
JS Execution 1000ms:                                                  <-------------------------------------------------------------------------------------------------->
DOM Ready   @1500ms:                                                                                                                                                      ?

JS First:

JS Download   400ms:<-------------------------------------->
CSS Download  500ms:<------------------------------------------------>
JS Execution 1000ms:                                        <-------------------------------------------------------------------------------------------------->
DOM Ready   @1400ms:                                                                                                                                            ?

Is there a way to check if a file is in use?

Would something like this help?

var fileWasWrittenSuccessfully = false;
while (fileWasWrittenSuccessfully == false)
{
    try
    {
        lock (new Object())
        {
            using (StreamWriter streamWriter = new StreamWriter("filepath.txt"), true))
            {
                streamWriter.WriteLine("text");
            }
        }

        fileWasWrittenSuccessfully = true;
    }
    catch (Exception)
    {

    }
}

MySQL Where DateTime is greater than today

SELECT * 
FROM customer 
WHERE joiningdate >= NOW();

Finding and removing non ascii characters from an Oracle Varchar2

Thanks, this worked for my purposes. BTW there is a missing single-quote in the example, above.

REGEXP_REPLACE (COLUMN,'[^' || CHR (32) || '-' || CHR (127) || ']', ' '))

I used it in a word-wrap function. Occasionally there was an embedded NewLine/ NL / CHR(10) / 0A in the incoming text that was messing things up.

"register" keyword in C?

Register keyword tells compiler to store the particular variable in CPU registers so that it could be accessible fast. From a programmer's point of view register keyword is used for the variables which are heavily used in a program, so that compiler can speedup the code. Although it depends on the compiler whether to keep the variable in CPU registers or main memory.

How to disable margin-collapsing?

I know that this is a very old post but just wanted to say that using flexbox on a parent element would disable margin collapsing for its child elements.

How to change the URL from "localhost" to something else, on a local system using wampserver?

Copy the hosts file and add 127.0.0.1 and name which you want to show or run at the browser link. For example:

127.0.0.1   abc

Then run abc/ as a local host in the browser.

1

Java: how to import a jar file from command line

try

java -cp "your_jar.jar:lib/referenced_jar.jar" com.your.main.Main

If you are on windows, you should use ; instead of :

How do I install Keras and Theano in Anaconda Python on Windows?

The trick is that you need to create an environment/workspace for Python. This solution should work for Python 2.7 but at the time of writing keras can run on python 3.5, especially if you have the latest anaconda installed (this took me awhile to figure out so I'll outline the steps I took to install KERAS in python 3.5):

Create environment/workspace for Python 3.5

  1. C:\conda create --name neuralnets python=3.5
  2. C:\activate neuralnets

Install everything (notice the neuralnets workspace in parenthesis on each line). Accept any dependencies each of those steps wants to install:

  1. (neuralnets) C:\conda install theano
  2. (neuralnets) C:\conda install mingw libpython
  3. (neuralnets) C:\pip install tensorflow
  4. (neuralnets) C:\pip install keras

Test it out:

(neuralnets) C:\python -c "from keras import backend; print(backend._BACKEND)"

Just remember, if you want to work in the workspace you always have to do:

C:\activate neuralnets

so you can launch Jupyter for example (assuming you also have Jupyter installed in this environment/workspace) as:

C:\activate neuralnets
(neuralnets) jupyter notebook

You can read more about managing and creating conda environments/workspaces at the follwing URL: https://conda.io/docs/using/envs.html

Swift days between two NSDates

Here is my answer for Swift 2:

func daysBetweenDates(startDate: NSDate, endDate: NSDate) -> Int
{
    let calendar = NSCalendar.currentCalendar()

    let components = calendar.components([.Day], fromDate: startDate, toDate: endDate, options: [])

    return components.day
}

How to convert string to double with proper cultureinfo

I have this function in my toolbelt since years ago (all the function and variable names are messy and mixing Spanish and English, sorry for that).

It lets the user use , and . to separate the decimals and will try to do the best if both symbols are used.

    Public Shared Function TryCDec(ByVal texto As String, Optional ByVal DefaultValue As Decimal = 0) As Decimal

        If String.IsNullOrEmpty(texto) Then
            Return DefaultValue
        End If

        Dim CurAsTexto As String = texto.Trim.Replace("$", "").Replace(" ", "")

        ''// You can probably use a more modern way to find out the
        ''// System current locale, this function was done long time ago
        Dim SepDecimal As String, SepMiles As String
        If CDbl("3,24") = 324 Then
            SepDecimal = "."
            SepMiles = ","
        Else
            SepDecimal = ","
            SepMiles = "."
        End If

        If InStr(CurAsTexto, SepDecimal) > 0 Then
            If InStr(CurAsTexto, SepMiles) > 0 Then
                ''//both symbols was used find out what was correct
                If InStr(CurAsTexto, SepDecimal) > InStr(CurAsTexto, SepMiles) Then
                    ''// The usage was correct, but get rid of thousand separator
                    CurAsTexto = Replace(CurAsTexto, SepMiles, "")
                Else
                    ''// The usage was incorrect, but get rid of decimal separator and then replace it
                    CurAsTexto = Replace(CurAsTexto, SepDecimal, "")
                    CurAsTexto = Replace(CurAsTexto, SepMiles, SepDecimal)
                End If
            End If
        Else
            CurAsTexto = Replace(CurAsTexto, SepMiles, SepDecimal)
        End If
        ''// At last we try to tryParse, just in case
        Dim retval As Decimal = DefaultValue
        Decimal.TryParse(CurAsTexto, retval)
        Return retval
    End Function

UnicodeEncodeError: 'latin-1' codec can't encode character

Latin-1 (aka ISO 8859-1) is a single octet character encoding scheme, and you can't fit \u201c () into a byte.

Did you mean to use UTF-8 encoding?

Correct way of getting Client's IP Addresses from http.Request

Looking at http.Request you can find the following member variables:

// HTTP defines that header names are case-insensitive.
// The request parser implements this by canonicalizing the
// name, making the first character and any characters
// following a hyphen uppercase and the rest lowercase.
//
// For client requests certain headers are automatically
// added and may override values in Header.
//
// See the documentation for the Request.Write method.
Header Header

// RemoteAddr allows HTTP servers and other software to record
// the network address that sent the request, usually for
// logging. This field is not filled in by ReadRequest and
// has no defined format. The HTTP server in this package
// sets RemoteAddr to an "IP:port" address before invoking a
// handler.
// This field is ignored by the HTTP client.
RemoteAddr string

You can use RemoteAddr to get the remote client's IP address and port (the format is "IP:port"), which is the address of the original requestor or the last proxy (for example a load balancer which lives in front of your server).

This is all you have for sure.

Then you can investigate the headers, which are case-insensitive (per documentation above), meaning all of your examples will work and yield the same result:

req.Header.Get("X-Forwarded-For") // capitalisation
req.Header.Get("x-forwarded-for") // doesn't
req.Header.Get("X-FORWARDED-FOR") // matter

This is because internally http.Header.Get will normalise the key for you. (If you want to access header map directly, and not through Get, you would need to use http.CanonicalHeaderKey first.)

Finally, "X-Forwarded-For" is probably the field you want to take a look at in order to grab more information about client's IP. This greatly depends on the HTTP software used on the remote side though, as client can put anything in there if it wishes to. Also, note the expected format of this field is the comma+space separated list of IP addresses. You will need to parse it a little bit to get a single IP of your choice (probably the first one in the list), for example:

// Assuming format is as expected
ips := strings.Split("10.0.0.1, 10.0.0.2, 10.0.0.3", ", ")
for _, ip := range ips {
    fmt.Println(ip)
}

will produce:

10.0.0.1
10.0.0.2
10.0.0.3

What's the difference between %s and %d in Python string formatting?

They are format specifiers. They are used when you want to include the value of your Python expressions into strings, with a specific format enforced.

See Dive into Python for a relatively detailed introduction.

jQuery if Element has an ID?

Pure js approach:

var elem = document.getElementsByClassName('parent');
alert(elem[0].hasAttribute('id'));

JsFiddle Demo

Relationship between hashCode and equals method in Java

According to the doc, the default implementation of hashCode will return some integer that differ for every object

As much as is reasonably practical, the hashCode method defined by class Object does return distinct integers for distinct objects. (This is typically implemented by converting the internal address of the object into an integer, but this implementation
technique is not required by the JavaTM programming language.)

However some time you want the hash code to be the same for different object that have the same meaning. For example

Student s1 = new Student("John", 18);
Student s2 = new Student("John", 18);
s1.hashCode() != s2.hashCode(); // With the default implementation of hashCode

This kind of problem will be occur if you use a hash data structure in the collection framework such as HashTable, HashSet. Especially with collection such as HashSet you will end up having duplicate element and violate the Set contract.

How to install sklearn?

You didn't provide us which operating system are you on? If it is a Linux, make sure you have scipy installed as well, after that just do

pip install -U scikit-learn

If you are on windows you might want to check out these pages.

Oracle TNS names not showing when adding new connection to SQL Developer

You can always find out the location of the tnsnames.ora file being used by running TNSPING to check connectivity (9i or later):

C:\>tnsping dev

TNS Ping Utility for 32-bit Windows: Version 10.2.0.1.0 - Production on 08-JAN-2009 12:48:38

Copyright (c) 1997, 2005, Oracle.  All rights reserved.

Used parameter files:
C:\oracle\product\10.2.0\client_1\NETWORK\ADMIN\sqlnet.ora


Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = XXX)(PORT = 1521)) (CONNECT_DATA = (SERVICE_NAME = DEV)))
OK (30 msec)

C:\>

Sometimes, the problem is with the entry you made in tnsnames.ora, not that the system can't find it. That said, I agree that having a tns_admin environment variable set is a Good Thing, since it avoids the inevitable issues that arise with determining exactly which tnsnames file is being used in systems with multiple oracle homes.

Concept behind putting wait(),notify() methods in Object class

These methods works on the locks and locks are associated with Object and not Threads. Hence, it is in Object class.

The methods wait(), notify() and notifyAll() are not only just methods, these are synchronization utility and used in communication mechanism among threads in Java.

For more detailed explanation, please visit : http://parameshk.blogspot.in/2013/11/why-wait-notify-and-notifyall-methods.html

EXTRACT() Hour in 24 Hour format

select to_char(tran_datetime,'HH24') from test;

TO_CHAR(tran_datetime,'HH24')
------------------
16      

Convert a negative number to a positive one in JavaScript

unsigned_value = Math.abs(signed_value);

Clear image on picturebox

For the Sake of Understanding:

Depending on how you're approaching your objective(s), keep in mind that the developer is responsible to Dispose everything that is no longer being used or necessary.

This means: Everything you've created along with your pictureBox (i.e: Graphics, List; etc) shall be disposed whenever it is no longer necessary.

For Instance: Let's say you have a Image File Loaded into your PictureBox, and you wish to somehow Delete that file. If you don't unload the Image File from PictureBox correctly; you won't be able to delete the file, as this will likely throw an Exception saying that the file is being used.

Therefore you'd be required to do something like:

pic_PhotoDisplay.Image.Dispose();
pic_PhotoDisplay.Image = null;
pic_PhotoDisplay.ImageLocation = null;
// Required if you've drawn something in the PictureBox. Just Don't forget to Dispose Graphic.
pic_PhotoDisplay.Update();

// Depending on your approach; Dispose the Graphics with Something Like:
gfx = null;
gfx.Clear();
gfx.Dispose();

Hope this helps you out.

How do I use InputFilter to limit characters in an EditText in Android?

This is how I created filter for the Name field in Edit Text.(First letter is CAPS, and allow only single space after every word.

public void setNameFilter() {
    InputFilter filter = new InputFilter() {
        @RequiresApi(api = Build.VERSION_CODES.KITKAT)
        public CharSequence filter(CharSequence source, int start, int end,
                                   Spanned dest, int dstart, int dend) {
            for (int i = start; i < end; i++) {
                if (dend == 0) {
                    if (Character.isSpaceChar(source.charAt(i)) ||
                            !Character.isAlphabetic(source.charAt(i))) {
                        return Constants.Delimiter.BLANK;
                    } else {
                        return String.valueOf(source.charAt(i)).toUpperCase();
                    }
                } else if (Character.isSpaceChar(source.charAt(i)) &&
                        String.valueOf(dest).endsWith(Constants.Delimiter.ONE_SPACE)) {
                    return Constants.Delimiter.BLANK;
                } else if ((!Character.isSpaceChar(source.charAt(i)) &&
                        !Character.isAlphabetic(source.charAt(i)))) {
                    return Constants.Delimiter.BLANK;
                }
            }
            return null;
        }
    };
    editText.setFilters(new InputFilter[]{filter, new InputFilter.LengthFilter(Constants.Length.NAME_LENGTH)});
}

How can I get the last 7 characters of a PHP string?

Use substr() with a negative number for the 2nd argument.

$newstring = substr($dynamicstring, -7);

From the php docs:

string substr ( string $string , int $start [, int $length ] )

If start is negative, the returned string will start at the start'th character from the end of string.

List<Object> and List<?>

package com.test;

import java.util.ArrayList;
import java.util.List;

public class TEst {

    public static void main(String[] args) {

        List<Integer> ls=new ArrayList<>();
        ls.add(1);
        ls.add(2);
        List<Integer> ls1=new ArrayList<>();
        ls1.add(3);
        ls1.add(4);
        List<List<Integer>> ls2=new ArrayList<>();
        ls2.add(ls);
        ls2.add(ls1);

        List<List<List<Integer>>> ls3=new ArrayList<>();
        ls3.add(ls2);


        m1(ls3);
    }

    private static void m1(List ls3) {
        for(Object ls4:ls3)
        {
             if(ls4 instanceof List)    
             {
                m1((List)ls4);
             }else {
                 System.out.print(ls4);
             }

        }
    }

}

Centering floating divs within another div

display: inline-block; won't work in any of IE browsers. Here is what I used.

// change the width of #boxContainer to 
// 1-2 pixels higher than total width of the boxes inside:

#boxContainer {         
    width: 800px; 
    height: auto;
    text-align: center;
    margin-left: auto;
    margin-right: auto;
}

#Box{
    width: 240px; 
    height: 90px;
    background-color: #FFF;
    float: left;
    margin-left: 10px;
    margin-right: 10px;
}

Position a CSS background image x pixels from the right?

I was trying to do a similar task to get a dropdown arrow always on the right side of the table header and came up with this which seemed to work in Chrome and Firefox, but safari was telling me it was an invalid property.

background: url(http://goo.gl/P93P5Q) center right 10px no-repeat;

After doing a bit of messing around in the inspector, I came up with this cross-browser solution that works in IE8+, Chrome, Firefox, and Safari, as well as responsive designs.

background: url(http://goo.gl/P93P5Q) no-repeat 95% center;

Here is a codepen of how it looks and works. Codepen is written with SCSS - http://cdpn.io/xqGbk

The operation couldn’t be completed. (com.facebook.sdk error 2.) ios6

I solve my problem by passing nil permission while login.

[FBSession openActiveSessionWithReadPermissions:nil
                                       allowLoginUI:YES
                                  completionHandler:

How to split a string in Haskell?

If you use Data.Text, there is splitOn:

http://hackage.haskell.org/packages/archive/text/0.11.2.0/doc/html/Data-Text.html#v:splitOn

This is built in the Haskell Platform.

So for instance:

import qualified Data.Text as T
main = print $ T.splitOn (T.pack " ") (T.pack "this is a test")

or:

{-# LANGUAGE OverloadedStrings #-}

import qualified Data.Text as T
main = print $ T.splitOn " " "this is a test"

Is it possible to cast a Stream in Java 8?

This looks a little ugly. Is it possible to cast an entire stream to a different type? Like cast Stream<Object> to a Stream<Client>?

No that wouldn't be possible. This is not new in Java 8. This is specific to generics. A List<Object> is not a super type of List<String>, so you can't just cast a List<Object> to a List<String>.

Similar is the issue here. You can't cast Stream<Object> to Stream<Client>. Of course you can cast it indirectly like this:

Stream<Client> intStream = (Stream<Client>) (Stream<?>)stream;

but that is not safe, and might fail at runtime. The underlying reason for this is, generics in Java are implemented using erasure. So, there is no type information available about which type of Stream it is at runtime. Everything is just Stream.

BTW, what's wrong with your approach? Looks fine to me.

Angular 4.3 - HttpClient set params

Just wanted to add that if you want to add several parameters with the same key name for example: www.test.com/home?id=1&id=2

let params = new HttpParams();
params = params.append(key, value);

Use append, if you use set, it will overwrite the previous value with the same key name.

Problems with a PHP shell script: "Could not open input file"

Have you tried:

#!/usr/local/bin/php

I.e. without the -q part? That's what the error message "Could not open input file: -q" means. The first argument to php if it doesn't look like an option is the name of the PHP file to execute, and -q is CGI only.

EDIT: A couple of (non-related) tips:

  1. You don't need to terminate the last block of PHP with ?>. In fact, it is often better not to.
  2. When executed on the command line, PHP defines the global constant STDIN to fopen("php://stdin", "r"). You can use that instead of opening "php://stdin" a second time: $fd = STDIN;

Getting a random value from a JavaScript array

If you have fixed values (like a month name list) and want a one-line solution

var result = ['January', 'February', 'March'][Math.floor(Math.random() * 3)]

The second part of the array is an access operation as described in Why does [5,6,8,7][1,2] = 8 in JavaScript?

How do I create an abstract base class in JavaScript?

Javascript can have inheritance, check out the URL below:

http://www.webreference.com/js/column79/

Andrew

Why are C++ inline functions in the header?

I know this is an old thread but thought I should mention that the extern keyword. I've recently ran into this issue and solved as follows

Helper.h

namespace DX
{
    extern inline void ThrowIfFailed(HRESULT hr);
}

Helper.cpp

namespace DX
{
    inline void ThrowIfFailed(HRESULT hr)
    {
        if (FAILED(hr))
        {
            std::stringstream ss;
            ss << "#" << hr;
            throw std::exception(ss.str().c_str());
        }
    }
}

Visual Studio 2017 errors on standard headers

If anyone's still stuck on this, the easiest solution I found was to "Retarget Solution". In my case, the project was built of SDK 8.1, upgrading to VS2017 brought with it SDK 10.0.xxx.

To retarget solution: Project->Retarget Solution->"Select whichever SDK you have installed"->OK

From there on you can simply build/debug your solution. Hope it helps

enter image description here

How to stop Python closing immediately when executed in Microsoft Windows

I know a simple answer! Open your cmd, the type in: cd C:\directory your file is in and then type python your progam.py

Bootstrap combining rows (rowspan)

_x000D_
_x000D_
div {_x000D_
  height:50px;_x000D_
}_x000D_
.short-div {_x000D_
  height:25px;_x000D_
}
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css" rel="stylesheet" />_x000D_
_x000D_
<div class="container">_x000D_
  <h1>Responsive Bootstrap</h1>_x000D_
  <div class="row">_x000D_
    <div class="col-lg-5 col-md-5 col-sm-5 col-xs-5" style="background-color:red;">Span 5</div>_x000D_
    <div class="col-lg-3 col-md-3 col-sm-3 col-xs-3" style="background-color:blue">Span 3</div>_x000D_
    <div class="col-lg-2 col-md-2 col-sm-3 col-xs-2" style="padding:0px">_x000D_
      <div class="short-div" style="background-color:green">Span 2</div>_x000D_
      <div class="short-div" style="background-color:purple">Span 2</div>_x000D_
    </div>_x000D_
    <div class="col-lg-2 col-md-2 col-sm-3 col-xs-2" style="background-color:yellow">Span 2</div>_x000D_
  </div>_x000D_
</div>_x000D_
<div class="container-fluid">_x000D_
  <div class="row-fluid">_x000D_
    <div class="col-lg-6 col-md-6 col-sm-6 col-xs-6">_x000D_
      <div class="short-div" style="background-color:#999">Span 6</div>_x000D_
      <div class="short-div">Span 6</div>_x000D_
    </div>_x000D_
    <div class="col-lg-6 col-md-6 col-sm-6 col-xs-6" style="background-color:#ccc">Span 6</div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Laravel 5 How to switch from Production mode

What you could also have a look at is the exposed method Application->loadEnvironmentFrom($file)

I needed one application to run on multiple subdomains. So in bootstrap/app.php I added something like:

$envFile = '.env';
// change $envFile conditionally here
$app->loadEnvironmentFrom($envFile);

Controlling Spacing Between Table Cells

Use border-collapse and border-spacing to get spaces between the table cells. I would not recommend using floating cells as suggested by QQping.

JSFiddle

Create table (structure) from existing table

If you want to create a table with the only structure to be copied from the original table then you can use the following command to do that.

create table <tablename> as select * from <sourcetablename> where 1>2;

By this false condition you can leave the records and copy the structure.

How to use PowerShell select-string to find more than one pattern in a file?

To search for multiple matches in each file, we can sequence several Select-String calls:

Get-ChildItem C:\Logs |
  where { $_ | Select-String -Pattern 'VendorEnquiry' } |
  where { $_ | Select-String -Pattern 'Failed' } |
  ...

At each step, files that do not contain the current pattern will be filtered out, ensuring that the final list of files contains all of the search terms.

Rather than writing out each Select-String call manually, we can simplify this with a filter to match multiple patterns:

filter MultiSelect-String( [string[]]$Patterns ) {
  # Check the current item against all patterns.
  foreach( $Pattern in $Patterns ) {
    # If one of the patterns does not match, skip the item.
    $matched = @($_ | Select-String -Pattern $Pattern)
    if( -not $matched ) {
      return
    }
  }

  # If all patterns matched, pass the item through.
  $_
}

Get-ChildItem C:\Logs | MultiSelect-String 'VendorEnquiry','Failed',...


Now, to satisfy the "Logtime about 11:30 am" part of the example would require finding the log time corresponding to each failure entry. How to do this is highly dependent on the actual structure of the files, but testing for "about" is relatively simple:

function AboutTime( [DateTime]$time, [DateTime]$target, [TimeSpan]$epsilon ) {
  $time -le ($target + $epsilon) -and $time -ge ($target - $epsilon)
}

PS> $epsilon = [TimeSpan]::FromMinutes(5)
PS> $target = [DateTime]'11:30am'
PS> AboutTime '11:00am' $target $epsilon
False
PS> AboutTime '11:28am' $target $epsilon
True
PS> AboutTime '11:35am' $target $epsilon
True

How to get UTC value for SYSDATE on Oracle

Usually, I work with DATE columns, not the larger but more precise TIMESTAMP used by some answers.

The following will return the current UTC date as just that -- a DATE.

CAST(sys_extract_utc(SYSTIMESTAMP) AS DATE)

I often store dates like this, usually with the field name ending in _UTC to make it clear for the developer. This allows me to avoid the complexity of time zones until last-minute conversion by the user's client. Oracle can store time zone detail with some data types, but those types require more table space than DATE, and knowledge of the original time zone is not always required.

How do I seed a random class to avoid getting duplicate random values

A good seed generation for me is:

Random rand = new Random(Guid.NewGuid().GetHashCode());

It is very random. The seed is always different because the seed is also random generated.

How to convert a const char * to std::string

There is a constructor accepting two pointer parameters, so the code is simply

 std::string cppstr(cstr, cstr + min(max_length, strlen(cstr)));

this is also going to be as efficient as std::string cppstr(cstr) if the length is smaller than max_length.

Parsing JSON array into java.util.List with Gson

I read solution from official website of Gson at here

And this code for you:

    String json = "{"client":"127.0.0.1","servers":["8.8.8.8","8.8.4.4","156.154.70.1","156.154.71.1"]}";

    JsonObject jsonObject = new Gson().fromJson(json, JsonObject.class);
    JsonArray jsonArray = jsonObject.getAsJsonArray("servers");

    String[] arrName = new Gson().fromJson(jsonArray, String[].class);

    List<String> lstName = new ArrayList<>();
    lstName = Arrays.asList(arrName);

    for (String str : lstName) {
        System.out.println(str);
    }    

Result show on monitor:

8.8.8.8
8.8.4.4
156.154.70.1
156.154.71.1

How do I format {{$timestamp}} as MM/DD/YYYY in Postman?

Any future date in JavaScript (postman test uses JavaScript) can be retrieved as:

var dateNow = new Date();  
var twoWeeksFutureDate = new Date(dateNow.setDate(dateNow.getDate() + 14)).toISOString();

postman.setEnvironmentVariable("future-date", twoWeeksFutureDate);

How to create the most compact mapping n ? isprime(n) up to a limit N?

Python 3:

def is_prime(a):
    return a > 1 and all(a % i for i in range(2, int(a**0.5) + 1))

Java String import

Everything in the java.lang package is implicitly imported (including String) and you do not need to do so yourself. This is simply a feature of the Java language. ArrayList and HashMap are however in the java.util package, which is not implicitly imported.

The package java.lang mostly includes essential features, such a class version of primitives, basic exceptions and the Object class. This being integral to most programs, forcing people to import them is redundant and thus the contents of this package are implicitly imported.

How to run Pip commands from CMD

Make sure to also add "C:\Python27\Scripts" to your path. pip.exe should be in that folder. Then you can just run:

C:\> pip install modulename

fatal: ambiguous argument 'origin': unknown revision or path not in the working tree

This worked for me on win replace REL_PATH_TO_FILE with the relative path to the file to remove Removing sensitive data from a repository The docs say full path - but that errored for me -so I tried rel path and it worked.

<from the repo dir>git filter-branch --force --index-filter "git rm --cached --ignore-unmatch REL_PATH_TO_FILE" --prune-empty --tag-name-filter cat -- --all

Add CSS class to a div in code behind

For a non ASP.NET control, i.e. HTML controls like div, table, td, tr, etc. you need to first make them a server control, assign an ID, and then assign a property from server code:

ASPX page

<head>
    <style type="text/css">
        .top_rounded
        {
            height: 75px;
            width: 75px;
            border: 2px solid;
            border-radius: 5px;
            -moz-border-radius: 5px; /* Firefox 3.6 and earlier */
            border-color: #9c1c1f;
        }
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <div runat="server" id="myDiv">This is my div</div>
    </form>
</body>

CS page

myDiv.Attributes.Add("class", "top_rounded");

How to find all the subclasses of a class given its name?

If you just want direct subclasses then .__subclasses__() works fine. If you want all subclasses, subclasses of subclasses, and so on, you'll need a function to do that for you.

Here's a simple, readable function that recursively finds all subclasses of a given class:

def get_all_subclasses(cls):
    all_subclasses = []

    for subclass in cls.__subclasses__():
        all_subclasses.append(subclass)
        all_subclasses.extend(get_all_subclasses(subclass))

    return all_subclasses

How can I add items to an empty set in python

When you assign a variable to empty curly braces {} eg: new_set = {}, it becomes a dictionary. To create an empty set, assign the variable to a 'set()' ie: new_set = set()

What's the difference between ISO 8601 and RFC 3339 Date Formats?

You shouldn't have to care that much. RFC 3339, according to itself, is a set of standards derived from ISO 8601. There's quite a few minute differences though, and they're all outlined in RFC 3339. I could go through them all here, but you'd probably do better just reading the document for yourself in the event you're worried:

http://tools.ietf.org/html/rfc3339

What's the meaning of exception code "EXC_I386_GPFLT"?

I'm seeing this error code in rotation crashes on Xcode 12.0 Beta 6, only on the iOS 14 simulator. It doesn't crash on my real device running iOS 13 though! So if you're running beta stuff and seeing rotation crashes in the simulator, maybe you just need to run on a real device with a non-beta iOS version.

How to stick text to the bottom of the page?

Try this

 <head>
 <style type ="text/css" >
   .footer{ 
       position: fixed;     
       text-align: center;    
       bottom: 0px; 
       width: 100%;
   }  
</style>
</head>
<body>
    <div class="footer">All Rights Reserved</div>
</body>

Html ordered list 1.1, 1.2 (Nested counters and scope) not working

Keep it Simple!

Simpler and a Standard solution to increment the number and to retain the dot at the end. Even if you get the css right, it will not work if your HTML is not correct. see below.

CSS

ol {
  counter-reset: item;
}
ol li {
  display: block;
}
ol li:before {
  content: counters(item, ". ") ". ";
  counter-increment: item;
}

SASS

ol {
    counter-reset: item;
    li {
        display: block;
        &:before {
            content: counters(item, ". ") ". ";
            counter-increment: item
        }
    }
}

HTML Parent Child

If you add the child make sure the it is under the parent li.

<!-- WRONG -->
<ol>
    <li>Parent 1</li> <!-- Parent is Individual. Not hugging -->
        <ol> 
            <li>Child</li>
        </ol>
    <li>Parent 2</li>
</ol>

<!-- RIGHT -->
<ol>
    <li>Parent 1 
        <ol> 
            <li>Child</li>
        </ol>
    </li> <!-- Parent is Hugging the child -->
    <li>Parent 2</li>
</ol>

Value cannot be null. Parameter name: source

This exception will be returned if you attempt to count values in a null collection.

For example the below works when Errors is not null, however if Errors is null then the Value cannot be null. Parameter name: source exception occurs.

if (graphQLResponse.Errors.Count() > 0)

This exception can be avoided by checking for null instead.

if (graphQLResponse.Errors != null)

SQL: Two select statements in one query

You can combine data from the two tables, order by goals highest first and then choose the top two like this:

MySQL

select *
from (
  select * from tblMadrid
  union all
  select * from tblBarcelona
) alldata
order by goals desc
limit 0,2;

SQL Server

select top 2 *
from (
  select * from tblMadrid
  union all
  select * from tblBarcelona
) alldata
order by goals desc;

If you only want Messi and Ronaldo

select * from tblBarcelona where name = 'messi'
union all
select * from tblMadrid where name = 'ronaldo'

To ensure that messi is at the top of the result, you can do something like this:

select * from (
  select * from tblBarcelona where name = 'messi'
  union all
  select * from tblMadrid where name = 'ronaldo'
) stars
order by name;

Non-Static method cannot be referenced from a static context with methods and variables

You should place Scanner input = new Scanner (System.in); into the main method rather than creating the input object outside.

Trying to use fetch and pass in mode: no-cors

mode: 'no-cors' won’t magically make things work. In fact it makes things worse, because one effect it has is to tell browsers, “Block my frontend JavaScript code from looking at contents of the response body and headers under all circumstances.” Of course you almost never want that.

What happens with cross-origin requests from frontend JavaScript is that browsers by default block frontend code from accessing resources cross-origin. If Access-Control-Allow-Origin is in a response, then browsers will relax that blocking and allow your code to access the response.

But if a site sends no Access-Control-Allow-Origin in its responses, your frontend code can’t directly access responses from that site. In particular, you can’t fix it by specifying mode: 'no-cors' (in fact that’ll ensure your frontend code can’t access the response contents).

However, one thing that will work: if you send your request through a CORS proxy.

You can also easily deploy your own proxy to Heroku in literally just 2-3 minutes, with 5 commands:

git clone https://github.com/Rob--W/cors-anywhere.git
cd cors-anywhere/
npm install
heroku create
git push heroku master

After running those commands, you’ll end up with your own CORS Anywhere server running at, for example, https://cryptic-headland-94862.herokuapp.com/.

Prefix your request URL with your proxy URL; for example:

https://cryptic-headland-94862.herokuapp.com/https://example.com

Adding the proxy URL as a prefix causes the request to get made through your proxy, which then:

  1. Forwards the request to https://example.com.
  2. Receives the response from https://example.com.
  3. Adds the Access-Control-Allow-Origin header to the response.
  4. Passes that response, with that added header, back to the requesting frontend code.

The browser then allows the frontend code to access the response, because that response with the Access-Control-Allow-Origin response header is what the browser sees.

This works even if the request is one that triggers browsers to do a CORS preflight OPTIONS request, because in that case, the proxy also sends back the Access-Control-Allow-Headers and Access-Control-Allow-Methods headers needed to make the preflight successful.


I can hit this endpoint, http://catfacts-api.appspot.com/api/facts?number=99 via Postman

https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS explains why it is that even though you can access the response with Postman, browsers won’t let you access the response cross-origin from frontend JavaScript code running in a web app unless the response includes an Access-Control-Allow-Origin response header.

http://catfacts-api.appspot.com/api/facts?number=99 has no Access-Control-Allow-Origin response header, so there’s no way your frontend code can access the response cross-origin.

Your browser can get the response fine and you can see it in Postman and even in browser devtools—but that doesn’t mean browsers will expose it to your code. They won’t, because it has no Access-Control-Allow-Origin response header. So you must instead use a proxy to get it.

The proxy makes the request to that site, gets the response, adds the Access-Control-Allow-Origin response header and any other CORS headers needed, then passes that back to your requesting code. And that response with the Access-Control-Allow-Origin header added is what the browser sees, so the browser lets your frontend code actually access the response.


So I am trying to pass in an object, to my Fetch which will disable CORS

You don’t want to do that. To be clear, when you say you want to “disable CORS” it seems you actually mean you want to disable the same-origin policy. CORS itself is actually a way to do that — CORS is a way to loosen the same-origin policy, not a way to restrict it.

But anyway, it’s true you can — in just your local environment — do things like give your browser runtime flags to disable security and run insecurely, or you can install a browser extension locally to get around the same-origin policy, but all that does is change the situation just for you locally.

No matter what you change locally, anybody else trying to use your app is still going to run into the same-origin policy, and there’s no way you can disable that for other users of your app.

You most likely never want to use mode: 'no-cors' in practice except in a few limited cases, and even then only if you know exactly what you’re doing and what the effects are. That’s because what setting mode: 'no-cors' actually says to the browser is, “Block my frontend JavaScript code from looking into the contents of the response body and headers under all circumstances.” In most cases that’s obviously really not what you want.


As far as the cases when you would want to consider using mode: 'no-cors', see the answer at What limitations apply to opaque responses? for the details. The gist of it is that the cases are:

  • In the limited case when you’re using JavaScript to put content from another origin into a <script>, <link rel=stylesheet>, <img>, <video>, <audio>, <object>, <embed>, or <iframe> element (which works because embedding of resources cross-origin is allowed for those) — but for some reason you don’t want to or can’t do that just by having the markup of the document use the resource URL as the href or src attribute for the element.

  • When the only thing you want to do with a resource is to cache it. As alluded to in the answer What limitations apply to opaque responses?, in practice the scenario that applies to is when you’re using Service Workers, in which case the API that’s relevant is the Cache Storage API.

But even in those limited cases, there are some important gotchas to be aware of; see the answer at What limitations apply to opaque responses? for the details.


I have also tried to pass in the object { mode: 'opaque'}

There is no mode: 'opaque' request mode — opaque is instead just a property of the response, and browsers set that opaque property on responses from requests sent with the no-cors mode.

But incidentally the word opaque is a pretty explicit signal about the nature of the response you end up with: “opaque” means you can’t see it.

Solving sslv3 alert handshake failure when trying to use a client certificate

Not a definite answer but too much to fit in comments:

I hypothesize they gave you a cert that either has a wrong issuer (although their server could use a more specific alert code for that) or a wrong subject. We know the cert matches your privatekey -- because both curl and openssl client paired them without complaining about a mismatch; but we don't actually know it matches their desired CA(s) -- because your curl uses openssl and openssl SSL client does NOT enforce that a configured client cert matches certreq.CAs.

Do openssl x509 <clientcert.pem -noout -subject -issuer and the same on the cert from the test P12 that works. Do openssl s_client (or check the one you did) and look under Acceptable client certificate CA names; the name there or one of them should match (exactly!) the issuer(s) of your certs. If not, that's most likely your problem and you need to check with them you submitted your CSR to the correct place and in the correct way. Perhaps they have different regimes in different regions, or business lines, or test vs prod, or active vs pending, etc.

If the issuer of your cert does match desiredCAs, compare its subject to the working (test-P12) one: are they in similar format? are there any components in the working one not present in yours? If they allow it, try generating and submitting a new CSR with a subject name exactly the same as the test-P12 one, or as close as you can get, and see if that produces a cert that works better. (You don't have to generate a new key to do this, but if you choose to, keep track of which certs match which keys so you don't get them mixed up.) If that doesn't help look at the certificate extensions with openssl x509 <cert -noout -text for any difference(s) that might reasonably be related to subject authorization, like KeyUsage, ExtendedKeyUsage, maybe Policy, maybe Constraints, maybe even something nonstandard.

If all else fails, ask the server operator(s) what their logs say about the problem, or if you have access look at the logs yourself.

Resource interpreted as stylesheet but transferred with MIME type text/html (seems not related with web server)

Based on the other answers it seems like this message has a lot of causes, I thought I'd just share my individual solution in case anyone has my exact problem in the future.

Our site loads the CSS files from an AWS Cloudfront distribution, which uses an S3 bucket as the origin. This particular S3 bucket was kept synced to a Linux server running Jenkins. The sync command via s3cmd sets the Content-Type for the S3 object automatically based on what the OS says (presumably based on the file extension). For some reason, in our server, all the types were being set correctly except .css files, which it gave the type text/plain. In S3, when you check the metadata in the properties of a file, you can set the type to whatever you want. Setting it to text/css allowed our site to correctly interpret the files as CSS and load correctly.

How can I list the contents of a directory in Python?

import os
os.listdir("path") # returns list

Getting the first index of an object

This will not give you the first one as javascript objects are unordered, however this is fine in some cases.

myObject[Object.keys(myObject)[0]]

What is the difference between XML and XSD?

Actually the XSD is XML itself. Its purpose is to validate the structure of another XML document. The XSD is not mandatory for any XML, but it assures that the XML could be used for some particular purposes. The XML is only containing data in suitable format and structure.

Counting the number of option tags in a select tag in jQuery

Ok, i had a few problems because i was inside a

$('.my-dropdown').live('click', function(){  
});

I had multiples inside my page that's why i used a class.

My drop down was filled automatically by a ajax request when i clicked it, so i only had the element $(this)

so...

I had to do:

$('.my-dropdown').live('click', function(){
  total_tems = $(this).find('option').length;
});

There is an error in XML document (1, 41)

In my case I had a float value expected where xml had a null value so be sure to search for float and int data type in your xsd map

Get only filename from url in php without any variable values which exist in the url

Use parse_url() as Pekka said:

<?php
$url = 'http://www.example.com/search.php?arg1=arg2';

$parts = parse_url($url);

$str = $parts['scheme'].'://'.$parts['host'].$parts['path'];

echo $str;
?>

http://codepad.org/NBBf4yTB

In this example the optional username and password aren't output!

How to convert buffered image to image and vice-versa?

You can try saving (or writing) the Buffered Image with the changes you made and then opening it as an Image.

EDIT:

try {
    // Retrieve Image
    BufferedImage buffer = ImageIO.read(new File("old.png"));;
    // Here you can rotate your image as you want (making your magic)
    File outputfile = new File("saved.png");
    ImageIO.write(buffer, "png", outputfile); // Write the Buffered Image into an output file
    Image image  = ImageIO.read(new File("saved.png")); // Opening again as an Image
} catch (IOException e) {
    ...
}

Javascript Print iframe contents only

I was stuck trying to implement this in typescript, all of the above would not work. I had to first cast the element in order for typescript to have access to the contentWindow.

let iframe = document.getElementById('frameId') as HTMLIFrameElement;
iframe.contentWindow.print();

javax.xml.bind.UnmarshalException: unexpected element. Expected elements are (none)

When you generate a JAXB model from an XML Schema, global elements that correspond to named complex types will have that metadata captured as an @XmlElementDecl annotation on a create method in the ObjectFactory class. Since you are creating the JAXBContext on just the DocumentType class this metadata isn't being processed. If you generated your JAXB model from an XML Schema then you should create the JAXBContext on the generated package name or ObjectFactory class to ensure all the necessary metadata is processed.

Example solution:

JAXBContext jaxbContext = JAXBContext.newInstance(my.generatedschema.dir.ObjectFactory.class);
DocumentType documentType = ((JAXBElement<DocumentType>) jaxbContext.createUnmarshaller().unmarshal(inputStream)).getValue();

Running bash script from within python

Adding an answer because I was directed here after asking how to run a bash script from python. You receive an error OSError: [Errno 2] file not found if your script takes in parameters. Lets say for instance your script took in a sleep time parameter: subprocess.call("sleep.sh 10") will not work, you must pass it as an array: subprocess.call(["sleep.sh", 10])

Data truncated for column?

Your problem is that at the moment your incoming_Cid column defined as CHAR(1) when it should be CHAR(34).

To fix this just issue this command to change your columns' length from 1 to 34

ALTER TABLE calls CHANGE incoming_Cid incoming_Cid CHAR(34);

Here is SQLFiddle demo

How to prevent form from being submitted?

var form = document.getElementById("idOfForm");
form.onsubmit = function() {
  return false;
}

Set Matplotlib colorbar size to match graph

This combination (and values near to these) seems to "magically" work for me to keep the colorbar scaled to the plot, no matter what size the display.

plt.colorbar(im,fraction=0.046, pad=0.04)

It also does not require sharing the axis which can get the plot out of square.

Selector on background color of TextView

For who is searching to do it without creating a background sector, just add those lines to the TextView

android:background="?android:attr/selectableItemBackground"
android:clickable="true"

Also to make it selectable use:

android:textIsSelectable="true"

Get current date in milliseconds

NSTimeInterval milisecondedDate = ([[NSDate date] timeIntervalSince1970] * 1000);

Regular expression for only characters a-z, A-Z

/^[a-zA-Z]+$/ 

Off the top of my head.

Edit:

Or if you don't like the weird looking literal syntax you can do it like this

new RegExp("^[a-zA-Z]+$");

How to measure time taken by a function to execute

there are multiple ways to achieve this objective :

  1. using console.time

    console.time('function');
    //run the function in between these two lines for that you need to 
    //measure time taken by the function. ("ex. function();")
    console.timeEnd('function');
    
  2. this is the most efficient way : using performance.now(), e.g.

    var v1 = performance.now();
    //run the function here for which you have top measure the time 
    var v2 = performance.now();
    console.log("total time  taken = "+(v2-v1)+"milliseconds");
    
  3. use +(add operator) or getTime()

    var h2 = +new Date(); //or
    var h2 = new Date().getTime();
    for(i=0;i<500;i++) { /* do something */}
    var h3 = +new Date();   //or 
    var h3 = new Date().getTime();
    var timeTaken = h3-h2;
    console.log("time ====", timeTaken);
    

Here's what happens when you apply the unary plus operator to a Date instance: Get the value of the Date instance in question Convert it to a Number

NOTE: getTime() gives better performance than unary + operator.

Are duplicate keys allowed in the definition of binary search trees?

Those three things you said are all true.

  • Keys are unique
  • To the left are keys less than this one
  • To the right are keys greater than this one

I suppose you could reverse your tree and put the smaller keys on the right, but really the "left" and "right" concept is just that: a visual concept to help us think about a data structure which doesn't really have a left or right, so it doesn't really matter.

How to make <label> and <input> appear on the same line on an HTML form?

I found "display:flex" style is a good way to make these elements in same line. No matter what kind of element in the div. Especially if the input class is form-control,other solutions like bootstrap, inline-block will not work well.

Example:

<div style="display:flex; flex-direction: row; justify-content: center; align-items: center">
    <label for="Student">Name:</label>
    <input name="Student" />
</div>

More detail about display:flex:

flex-direction: row, column

justify-content: flex-end, center, space-between, space-around

align-items: stretch, flex-start, flex-end, center

Reordering Chart Data Series

Excel 2010 - if you're looking to reorder the series on a pivot chart:

  • go to your underlying pivot table
  • right-click on one of the Column Labels for the series you're looking to adjust (Note: you need to click on one of the series headings (i.e. 'Saturday' or 'Sunday' in the example shown below) not the 'Column Labels' text itself)
  • in the pop-up menu, hover over 'Move' and then select an option from the resulting sub-menu to reposition the series variable.
  • your pivot chart will update itself accordingly

enter image description here

Under which circumstances textAlign property works in Flutter?

textAlign property only works when there is a more space left for the Text's content. Below are 2 examples which shows when textAlign has impact and when not.


No impact

For instance, in this example, it won't have any impact because there is no extra space for the content of the Text.

Text(
  "Hello",
  textAlign: TextAlign.end, // no impact
),

enter image description here


Has impact

If you wrap it in a Container and provide extra width such that it has more extra space.

Container(
  width: 200,
  color: Colors.orange,
  child: Text(
    "Hello",
    textAlign: TextAlign.end, // has impact
  ),
)

enter image description here

How to print strings with line breaks in java

private static final String mText = "SHOP MA" + "\n" +
        + "----------------------------" + "\n" +
        + "Pannampitiya" + newline +
        + "09-10-2012 harsha  no: 001" + "\n" +
        + "No  Item  Qty  Price  Amount" + "\n" +
        + "1 Bread 1 50.00  50.00" + "\n" +
        + "____________________________" + "\n";

This should work.

Regular Expression: Allow letters, numbers, and spaces (with at least one letter or number)

You can use a lookaround:

^(?=.*[A-Za-z0-9])[A-Za-z0-9 _]*$

It will check ahead that the string has a letter or number, if it does it will check that the rest of the chars meet your requirements. This can probably be improved upon, but it seems to work with my tests.

UPDATE:

Adding modifications suggested by Chris Lutz:

^(?=.*[^\W_])[\w ]*$/

How to send a JSON object using html form data

you code is fine but never executed, cause of submit button [type="submit"] just replace it by type=button

<input value="Submit" type="button" onclick="submitform()">

inside your script; form is not declared.

let form = document.forms[0];
xhr.open(form.method, form.action, true);

How to format a JavaScript date

Here is a script that does exactly what you want

https://github.com/UziTech/js-date-format

var d = new Date("2010-8-10");
document.write(d.format("DD-MMM-YYYY"));

Real time face detection OpenCV, Python

Your line:

img = cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) 

will draw a rectangle in the image, but the return value will be None, so img changes to None and cannot be drawn.

Try

cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2) 

Where can I download Eclipse Android bundle?

The Android Developer pages still state how you can download and use the ADT plugin for Eclipse:

  1. Start Eclipse, then select Help > Install New Software.
  2. Click Add, in the top-right corner.
  3. In the Add Repository dialog that appears, enter "ADT Plugin" for the Name and the following URL for the Location: https://dl-ssl.google.com/android/eclipse/
  4. Click OK.
  5. In the Available Software dialog, select the checkbox next to Developer Tools and click Next.
  6. In the next window, you'll see a list of the tools to be downloaded. Click Next.
  7. Read and accept the license agreements, then click Finish. If you get a security warning saying that the authenticity or validity of the software can't be established, click OK
  8. When the installation completes, restart Eclipse.

Links for the Eclipse ADT Bundle (found using Archive.org's WayBackMachine) I don't know how future-proof these links are. They all worked on February 27th, 2017.


Update (2015-06-29): Google will end development and official support for ADT in Eclipse at the end of this year and recommends switching to Android Studio.

Add tooltip to font awesome icon

Simply with native html & css :

<div class="tooltip">Hover over me
  <span class="tooltiptext">Tooltip text</span>
</div>

/* Tooltip container */
.tooltip {
  position: relative;
  display: inline-block;
  border-bottom: 1px dotted black; /* If you want dots under the hoverable text */
}

/* Tooltip text */
.tooltip .tooltiptext {
  visibility: hidden;
  width: 120px;
  background-color: #555;
  color: #fff;
  text-align: center;
  padding: 5px 0;
  border-radius: 6px;

  /* Position the tooltip text */
  position: absolute;
  z-index: 1;
  bottom: 125%;
  left: 50%;
  margin-left: -60px;

  /* Fade in tooltip */
  opacity: 0;
  transition: opacity 0.3s;
}

/* Tooltip arrow */
.tooltip .tooltiptext::after {
  content: "";
  position: absolute;
  top: 100%;
  left: 50%;
  margin-left: -5px;
  border-width: 5px;
  border-style: solid;
  border-color: #555 transparent transparent transparent;
}

/* Show the tooltip text when you mouse over the tooltip container */
.tooltip:hover .tooltiptext {
  visibility: visible;
  opacity: 1;
}

Here is the source of the example from w3schools

vba pass a group of cells as range to function

There is another way to pass multiple ranges to a function, which I think feels much cleaner for the user. When you call your function in the spreadsheet you wrap each set of ranges in brackets, for example: calculateIt( (A1,A3), (B6,B9) )

The above call assumes your two Sessions are in A1 and A3, and your two Customers are in B6 and B9.

To make this work, your function needs to loop through each of the Areas in the input ranges. For example:

Function calculateIt(Sessions As Range, Customers As Range) As Single

    ' check we passed the same number of areas
    If (Sessions.Areas.Count <> Customers.Areas.Count) Then
        calculateIt = CVErr(xlErrNA)
        Exit Function
    End If

    Dim mySession, myCustomers As Range

    ' run through each area and calculate
    For a = 1 To Sessions.Areas.Count

        Set mySession = Sessions.Areas(a)
        Set myCustomers = Customers.Areas(a)

        ' calculate them...
    Next a

End Function

The nice thing is, if you have both your inputs as a contiguous range, you can call this function just as you would a normal one, e.g. calculateIt(A1:A3, B6:B9).

Hope that helps :)

Total memory used by Python process?

import os, win32api, win32con, win32process
han = win32api.OpenProcess(win32con.PROCESS_QUERY_INFORMATION|win32con.PROCESS_VM_READ, 0, os.getpid())
process_memory = int(win32process.GetProcessMemoryInfo(han)['WorkingSetSize'])

What is cardinality in Databases?

Cardinality of a set is the namber of the elements in set for we have a set a > a,b,c < so ths set contain 3 elements 3 is the cardinality of that set

jQuery: Load Modal Dialog Contents via Ajax

may be this code may give you some idea.

http://blog.nemikor.com/2009/04/18/loading-a-page-into-a-dialog/

$(document).ready(function() {
    $('#page-help').each(function() {
        var $link = $(this);
        var $dialog = $('<div></div>')
            .load($link.attr('href'))
            .dialog({
                autoOpen: false,
                title: $link.attr('title'),
                width: 500,
                height: 300
            });

        $link.click(function() {
            $dialog.dialog('open');

            return false;
        });
    });
});

How do I get git to default to ssh and not https for new repositories

  • GitHub

    git config --global url.ssh://[email protected]/.insteadOf https://github.com/
    
  • BitBucket

    git config --global url.ssh://[email protected]/.insteadOf https://bitbucket.org/
    

That tells git to always use SSH instead of HTTPS when connecting to GitHub/BitBucket, so you'll authenticate by certificate by default, instead of being prompted for a password.

MySql Error: 1364 Field 'display_name' doesn't have default value

MySQL is most likely in STRICT mode, which isn't necessarily a bad thing, as you'll identify bugs/issues early and not just blindly think everything is working as you intended.

Change the column to allow null:

ALTER TABLE `x` CHANGE `display_name` `display_name` TEXT NULL

or, give it a default value as empty string:

ALTER TABLE `x` CHANGE `display_name` `display_name` TEXT NOT NULL DEFAULT ''

How do you create a custom AuthorizeAttribute in ASP.NET Core?

What is the current approach to make a custom AuthorizeAttribute

Easy: don't create your own AuthorizeAttribute.

For pure authorization scenarios (like restricting access to specific users only), the recommended approach is to use the new authorization block: https://github.com/aspnet/MusicStore/blob/1c0aeb08bb1ebd846726232226279bbe001782e1/samples/MusicStore/Startup.cs#L84-L92

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.Configure<AuthorizationOptions>(options =>
        {
            options.AddPolicy("ManageStore", policy => policy.RequireClaim("Action", "ManageStore"));
        });
    }
}

public class StoreController : Controller
{
    [Authorize(Policy = "ManageStore"), HttpGet]
    public async Task<IActionResult> Manage() { ... }
}

For authentication, it's best handled at the middleware level.

What are you trying to achieve exactly?

CURL ERROR: Recv failure: Connection reset by peer - PHP Curl

This is a firewall issue, if you are using a VMware application, make sure the firewall on the antivirus is turned off or allowing connections.

If this server is on a secure network, please have a look at firewall rules of the server.

Thanks Ganesh PNS

Where to find extensions installed folder for Google Chrome on Mac?

They are found on either one of the below locations depending on how chrome was installed

  • When chrome is installed at the user level, it's located at:

~/Users/<username>/Library/Application\ Support/Google/Chrome/Default/Extensions

  • When installed at the root level, it's at:

/Library/Application\ Support/Google/Chrome/Default/Extensions

Whitespaces in java

Why don't you check if text.trim() has a different length? :

if(text.length() == text.trim().length() || otherConditions){
    //your code
}

SyntaxError: Cannot use import statement outside a module

According to the official doc (https://nodejs.org/api/esm.html#esm_code_import_code_statements):

import statements are permitted only in ES modules. For similar functionality in CommonJS, see import().

To make Node treat your file as a ES module you need to (https://nodejs.org/api/esm.html#esm_enabling):

  • add "type": "module" to package.json
  • add "--experimental-modules" flag to the node call

Where value in column containing comma delimited values

select *
from YourTable
where ','+replace(col, ' ', '')+',' like '%,Cat,%'

Is there a format code shortcut for Visual Studio?

Right click on the code, and you have "Format Document". In my case it is Ctrl+Shift+I

enter image description here

What does $1 [QSA,L] mean in my .htaccess file?

If the following conditions are true, then rewrite the URL:
If the requested filename is not a directory,

RewriteCond %{REQUEST_FILENAME} !-d

and if the requested filename is not a regular file that exists,

RewriteCond %{REQUEST_FILENAME} !-f

and if the requested filename is not a symbolic link,

RewriteCond %{REQUEST_FILENAME} !-l

then rewrite the URL in the following way:
Take the whole request filename and provide it as the value of a "url" query parameter to index.php. Append any query string from the original URL as further query parameters (QSA), and stop processing this .htaccess file (L).

RewriteRule ^(.+)$ index.php?url=$1 [QSA,L]

Apache docs #flag_qsa

Another Example:

RewriteRule "/pages/(.+)" "/page.php?page=$1" [QSA]

With the [QSA] flag, a request for

/pages/123?one=two

will be mapped to

/page.php?page=123&one=two

GROUP BY having MAX date

Fast and easy with HAVING:

SELECT * FROM tblpm n 
FROM tblpm GROUP BY control_number 
HAVING date_updated=MAX(date_updated);

In the context of HAVING, MAX finds the max of each group. Only the latest entry in each group will satisfy date_updated=max(date_updated). If there's a tie for latest within a group, both will pass the HAVING filter, but GROUP BY means that only one will appear in the returned table.

Java HttpRequest JSON & Response Handling

The simplest way is using libraries like google-http-java-client but if you want parse the JSON response by yourself you can do that in a multiple ways, you can use org.json, json-simple, Gson, minimal-json, jackson-mapper-asl (from 1.x)... etc

A set of simple examples:

Using Gson:

import java.io.IOException;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;

public class Gson {

    public static void main(String[] args) {
    }

    public HttpResponse http(String url, String body) {

        try (CloseableHttpClient httpClient = HttpClientBuilder.create().build()) {
            HttpPost request = new HttpPost(url);
            StringEntity params = new StringEntity(body);
            request.addHeader("content-type", "application/json");
            request.setEntity(params);
            HttpResponse result = httpClient.execute(request);
            String json = EntityUtils.toString(result.getEntity(), "UTF-8");

            com.google.gson.Gson gson = new com.google.gson.Gson();
            Response respuesta = gson.fromJson(json, Response.class);

            System.out.println(respuesta.getExample());
            System.out.println(respuesta.getFr());

        } catch (IOException ex) {
        }
        return null;
    }

    public class Response{

        private String example;
        private String fr;

        public String getExample() {
            return example;
        }
        public void setExample(String example) {
            this.example = example;
        }
        public String getFr() {
            return fr;
        }
        public void setFr(String fr) {
            this.fr = fr;
        }
    }
}

Using json-simple:

import java.io.IOException;

import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
import org.json.simple.parser.JSONParser;

public class JsonSimple {

    public static void main(String[] args) {

    }

    public HttpResponse http(String url, String body) {

        try (CloseableHttpClient httpClient = HttpClientBuilder.create().build()) {
            HttpPost request = new HttpPost(url);
            StringEntity params = new StringEntity(body);
            request.addHeader("content-type", "application/json");
            request.setEntity(params);
            HttpResponse result = httpClient.execute(request);

            String json = EntityUtils.toString(result.getEntity(), "UTF-8");
            try {
                JSONParser parser = new JSONParser();
                Object resultObject = parser.parse(json);

                if (resultObject instanceof JSONArray) {
                    JSONArray array=(JSONArray)resultObject;
                    for (Object object : array) {
                        JSONObject obj =(JSONObject)object;
                        System.out.println(obj.get("example"));
                        System.out.println(obj.get("fr"));
                    }

                }else if (resultObject instanceof JSONObject) {
                    JSONObject obj =(JSONObject)resultObject;
                    System.out.println(obj.get("example"));
                    System.out.println(obj.get("fr"));
                }

            } catch (Exception e) {
                // TODO: handle exception
            }

        } catch (IOException ex) {
        }
        return null;
    }
}

etc...

Compare two files line by line and generate the difference in another file

Sometimes diff is the utility you need, but sometimes join is more appropriate. The files need to be pre-sorted or, if you are using a shell which supports process substitution such as bash, ksh or zsh, you can do the sort on the fly.

join -v 1 <(sort file1) <(sort file2)

difference between primary key and unique key

Unique Key (UK): It's a column or a group of columns that can identify a uniqueness in a row.

Primary Key (PK): It's also a column or group of columns that can identify a uniqueness in a row.

So the Primary key is just another name for unique key, but the default implementation in SQL Server is different for Primary and Unique Key.

By Default:

  1. PK creates a Clustered index and UK creates a Non Clustered Index.
  2. PK is not null, but UK allows nulls (Note: By Default)
  3. There can only be one and only one PK on a table, but there can be multiple UK's
  4. You can override the default implementation depending upon your need.

It really depends what is your aim when deciding whether to create a UK or PK. It follows an analogy like "If there is a team of three people, so all of them are peers, but there will be one of them who will be a pair of peers: PK and UK has similar relation.". I would suggest reading this article: The example given by the author may not seem suitable, but try to get an overall idea.

http://tsqltips.blogspot.com/2012/06/difference-between-unique-key-and.html

SQL Server principal "dbo" does not exist,

As the message said, you should set permission as owner to your user. So you can use following:

ALTER AUTHORIZATION 
ON DATABASE::[YourDBName]
TO [UserLogin];

Hope helpful! Leave comment if it's ok for you.

What is the difference between Scala's case class and class?

No one mentioned that case classes are also instances of Product and thus inherit these methods:

def productElement(n: Int): Any
def productArity: Int
def productIterator: Iterator[Any]

where the productArity returns the number of class parameters, productElement(i) returns the ith parameter, and productIterator allows iterating through them.

No Title Bar Android Theme

use android:theme="@android:style/Theme.NoTitleBar in manifest file's application tag to remove the title bar for whole application or put it in activity tag to remove the title bar from a single activity screen.

Excel VBA For Each Worksheet Loop

Try this more succinct code:

Sub LoopOverEachColumn()
    Dim WS As Worksheet
    For Each WS In ThisWorkbook.Worksheets
        ResizeColumns WS
    Next WS
End Sub

Private Sub ResizeColumns(WS As Worksheet)
    Dim StrSize As String
    Dim ColIter As Long
    StrSize = "20.14;9.71;35.86;30.57;23.57;21.43;18.43;23.86;27.43;36.71;30.29;31.14;31;41.14;33.86"
    For ColIter = 1 To 15
        WS.Columns(ColIter).ColumnWidth = Split(StrSize, ";")(ColIter - 1)
    Next ColIter
End Sub

If you want additional columns, just change 1 to 15 to 1 to X where X is the column index of the column you want, and append the column size you want to StrSize.

For example, if you want P:P to have a width of 25, just add ;25 to StrSize and change ColIter... to ColIter = 1 to 16.

Hope this helps.

Getting session value in javascript

var sessionVal = '@Session["EnergyUnit"]';
alert(sessionVal);

numbers not allowed (0-9) - Regex Expression in javascript

Something as simple as [a-z]+, or perhaps [\S]+, or even [a-zA-Z]+?

How to find the serial port number on Mac OS X?

While entering the serial port name into the code in arduino IDE, enter the whole port address i.e:

/dev/cu.usbmodem*

or

/dev/cu.UG-*

where the * is the port number.

And for the port number in case of mac just open terminal and type

ls /dev/*

and then search for the port that u have set in arduino IDE.

How to get relative path of a file in visual studio?

I also met the same problem and I was able to get it through. So let me explain the steps I applied. I shall explain it according to your scenario.

According to my method we need to use 'Path' class and 'Assembly' class in order to get the relative path.

So first Import System.IO and System.Reflection in using statements.

Then type the below given code line.

        var outPutDirectory = Path.GetDirectoryName(Assembly.GetExecutingAssembly(). CodeBase);

Actually above given line stores the path of the output directory of your project.(Here 'output' directory refers to the Debug folder of your project).

Now copy your FolderIcon directory in to the Debug folder. Then type the below given Line.

var iconPath = Path.Combine(outPutDirectory, "FolderIcon\\Folder.ico");

Now this 'iconPath ' variable contains the entire path of your Folder.ico. All you have to do is store it in a string variable. Use the line of code below for that.

string icon_path = new Uri(iconPath ).LocalPath;

Now you can use this icon_path string variable as your relative path to the icon.

Thanks.

long long int vs. long int vs. int64_t in C++

So my question is: Is there a way to tell the compiler that a long long int is the also a int64_t, just like long int is?

This is a good question or problem, but I suspect the answer is NO.

Also, a long int may not be a long long int.


# if __WORDSIZE == 64
typedef long int  int64_t;
# else
__extension__
typedef long long int  int64_t;
# endif

I believe this is libc. I suspect you want to go deeper.

In both 32-bit compile with GCC (and with 32- and 64-bit MSVC), the output of the program will be:

int:           0
int64_t:       1
long int:      0
long long int: 1

32-bit Linux uses the ILP32 data model. Integers, longs and pointers are 32-bit. The 64-bit type is a long long.

Microsoft documents the ranges at Data Type Ranges. The say the long long is equivalent to __int64.

However, the program resulting from a 64-bit GCC compile will output:

int:           0
int64_t:       1
long int:      1
long long int: 0

64-bit Linux uses the LP64 data model. Longs are 64-bit and long long are 64-bit. As with 32-bit, Microsoft documents the ranges at Data Type Ranges and long long is still __int64.

There's a ILP64 data model where everything is 64-bit. You have to do some extra work to get a definition for your word32 type. Also see papers like 64-Bit Programming Models: Why LP64?


But this is horribly hackish and does not scale well (actual functions of substance, uint64_t, etc)...

Yeah, it gets even better. GCC mixes and matches declarations that are supposed to take 64 bit types, so its easy to get into trouble even though you follow a particular data model. For example, the following causes a compile error and tells you to use -fpermissive:

#if __LP64__
typedef unsigned long word64;
#else
typedef unsigned long long word64;
#endif

// intel definition of rdrand64_step (http://software.intel.com/en-us/node/523864)
// extern int _rdrand64_step(unsigned __int64 *random_val);

// Try it:
word64 val;
int res = rdrand64_step(&val);

It results in:

error: invalid conversion from `word64* {aka long unsigned int*}' to `long long unsigned int*'

So, ignore LP64 and change it to:

typedef unsigned long long word64;

Then, wander over to a 64-bit ARM IoT gadget that defines LP64 and use NEON:

error: invalid conversion from `word64* {aka long long unsigned int*}' to `uint64_t*'

TypeError: method() takes 1 positional argument but 2 were given

In my case, I forgot to add the ()

I was calling the method like this

obj = className.myMethod

But it should be is like this

obj = className.myMethod()

ALTER TABLE, set null in not null column, PostgreSQL 9.1

First, Set :
ALTER TABLE person ALTER COLUMN phone DROP NOT NULL;

Java double.MAX_VALUE?

this states that Account.deposit(Double.MAX_VALUE); it is setting deposit value to MAX value of Double dataType.to procced for running tests.

Including external HTML file to another HTML file

You can use jquery load for that.

<script type="text/javascript">
$(document).ready(function(e) {
    $('#header').load('name.html',function(){alert('loaded')});
});
</script>

Don't forget to include jquery library befor above code.

PHP Redirect to another page after form submit

Right after @mail($email_to, $email_subject, $email_message, $headers);

header('Location: nextpage.php');

Note that you will never see 'Thanks for subscribing to our mailing list'

That should be on the next page, if you echo any text you will get an error because the headers would have been already created, if you want to redirect never return any text, not even a space!

Determine which element the mouse pointer is on top of in JavaScript

The following code will help you to get the element of the mouse pointer. The resulted elements will display in the console.

document.addEventListener('mousemove', function(e) {
    console.log(document.elementFromPoint(e.pageX, e.pageY)); 
})

How do I find the absolute position of an element using jQuery?

Note that $(element).offset() tells you the position of an element relative to the document. This works great in most circumstances, but in the case of position:fixed you can get unexpected results.

If your document is longer than the viewport and you have scrolled vertically toward the bottom of the document, then your position:fixed element's offset() value will be greater than the expected value by the amount you have scrolled.

If you are looking for a value relative to the viewport (window), rather than the document on a position:fixed element, you can subtract the document's scrollTop() value from the fixed element's offset().top value. Example: $("#el").offset().top - $(document).scrollTop()

If the position:fixed element's offset parent is the document, you want to read parseInt($.css('top')) instead.

How do I make a request using HTTP basic authentication with PHP curl?

There are multiple REST frameworks out there. I would strongly recommend looking into Slim mini Framework for PHP
Here is a list of others.

What is the difference between conversion specifiers %i and %d in formatted IO functions (*printf / *scanf)

These are identical for printf but different for scanf. For printf, both %d and %i designate a signed decimal integer. For scanf, %d and %i also means a signed integer but %i inteprets the input as a hexadecimal number if preceded by 0x and octal if preceded by 0 and otherwise interprets the input as decimal.

getting " (1) no such column: _id10 " error

I think you missed a equal sign at:

Cursor c = ourDatabase.query(DATABASE_TABLE, column, KEY_ROWID + "" + l, null, null, null, null);  

Change to:

Cursor c = ourDatabase.query(DATABASE_TABLE, column, KEY_ROWID + " = " + l, null, null, null, null); 

Rounding numbers to 2 digits after comma

UPDATE: Keep in mind, at the time the answer was initially written in 2010, the bellow function toFixed() worked slightly different. toFixed() seems to do some rounding now, but not in the strictly mathematical manner. So be careful with it. Do your tests... The method described bellow will do rounding well, as mathematician would expect.

  • toFixed() - method converts a number into a string, keeping a specified number of decimals. It does not actually rounds up a number, it truncates the number.
  • Math.round(n) - rounds a number to the nearest integer. Thus turning:

0.5 -> 1; 0.05 -> 0

so if you want to round, say number 0.55555, only to the second decimal place; you can do the following(this is step-by-step concept):

  • 0.55555 * 100 = 55.555
  • Math.Round(55.555) -> 56.000
  • 56.000 / 100 = 0.56000
  • (0.56000).toFixed(2) -> 0.56

and this is the code:

(Math.round(number * 100)/100).toFixed(2);

Scraping: SSL: CERTIFICATE_VERIFY_FAILED error for http://en.wikipedia.org

For anyone who is using anaconda, you would install the certifi package, see more at:

https://anaconda.org/anaconda/certifi

To install, type this line in your terminal:

conda install -c anaconda certifi

TypeScript error: Type 'void' is not assignable to type 'boolean'

It means that the callback function you passed to this.dataStore.data.find should return a boolean and have 3 parameters, two of which can be optional:

  • value: Conversations
  • index: number
  • obj: Conversation[]

However, your callback function does not return anything (returns void). You should pass a callback function with the correct return value:

this.dataStore.data.find((element, index, obj) => {
    // ...

    return true; // or false
});

or:

this.dataStore.data.find(element => {
    // ...

    return true; // or false
});

Reason why it's this way: the function you pass to the find method is called a predicate. The predicate here defines a boolean outcome based on conditions defined in the function itself, so that the find method can determine which value to find.

In practice, this means that the predicate is called for each item in data, and the first item in data for which your predicate returns true is the value returned by find.

How to fix the error; 'Error: Bootstrap tooltips require Tether (http://github.hubspot.com/tether/)'

To add to @adilapapaya's answer. For ember-cli users specifically, install tether with

bower install --save tether

and then include it in your ember-cli-build.js file before bootstrap, like so:

// tether (bootstrap 4 requirement)
app.import('bower_components/tether/dist/js/tether.min.js');

// bootstrap
app.import('bower_components/bootstrap/scss/bootstrap-flex.scss');
app.import('bower_components/bootstrap/dist/js/bootstrap.js');

Html.Textbox VS Html.TextboxFor

Html.TextBox amd Html.DropDownList are not strongly typed and hence they doesn't require a strongly typed view. This means that we can hardcode whatever name we want. On the other hand, Html.TextBoxFor and Html.DropDownListFor are strongly typed and requires a strongly typed view, and the name is inferred from the lambda expression.

Strongly typed HTML helpers also provide compile time checking.

Since, in real time, we mostly use strongly typed views, prefer to use Html.TextBoxFor and Html.DropDownListFor over their counterparts.

Whether, we use Html.TextBox & Html.DropDownList OR Html.TextBoxFor & Html.DropDownListFor, the end result is the same, that is they produce the same HTML.

Strongly typed HTML helpers are added in MVC2.

SQL DATEPART(dw,date) need monday = 1 and sunday = 7

I think this could work:

  select
    case when datepart(dw,[Date]) = 1 then 7 else DATEPART(DW,[Date])-1 end as WeekDay

How to remove an iOS app from the App Store

For permanently delete your app follow below steps.

Step 1 :- GO to My Apps App in iTunes Connect

enter image description here

Here you can see your all app which are currently on Appstore.

Step 2 :- Select your app which you want to delete.(click on app-name)

enter image description here

Step 3 :- Select Pricing and Availability Tab.

enter image description here

Step 4 :- Select Remove from sale option.

enter image description here

Step 5 :- Click on save Button.

Now you will see below your app like , Developer Removed it from sale in Red Symbol in place of Green.

enter image description here

Step 6 :- Now again Select your app and Go to App information Tab. you will see Delete App option. (need to scroll bit bottom)

enter image description here

Step 7 :- After clicking on Delete button you will get warning like this ,

enter image description here

Step 8 :- Click on Delete button.

Congratulation , You have Permanently deleted your app successfully from appstore. Now , you cant able to see app on appstore aswellas in your developer account.

Note :-

When you have selected only Remove from sale option you have not deleted app permanently. You can able to make your app live again by clicking on Available in all territories option Again.

enter image description here

How to grant all privileges to root user in MySQL 8.0

This may work:

grant all on dbtest.* to 'dbuser'@'%' identified by 'mysql_password';

SQL providerName in web.config

 WebConfigurationManager.ConnectionStrings["YourConnectionString"].ProviderName;

Node.js getaddrinfo ENOTFOUND

I got this issue resolved by removing non-desirable characters from the password for the connection. For example, I had these characters: <##% and it caused the problem (most probably hash tag was the root cause of the problem).

ng-change get new value and original value

You can use something like ng-change=someMethod({{user.id}}). By keeping your value in side {{expression}} it will evaluate expression in-line and gives you current value(value before ng-change method is called).

<select ng-model="selectedValue" ng-change="change(selectedValue, '{{selectedValue}}')">

An implementation of the fast Fourier transform (FFT) in C#

For a multi-threaded implementation tuned for Intel processors I'd check out Intel's MKL library. It's not free, but it's afforable (less than $100) and blazing fast - but you'd need to call it's C dll's via P/Invokes. The Exocortex project stopped development 6 years ago, so I'd be careful using it if this is an important project.

Which programming languages can be used to develop in Android?

Here's a list of languages that can be used to develop on android:

  • Java - primary android development language

  • Kotlin, language from JetBrains which received first-party support from Google, announced in Google I/O 2017

  • C++ - NDK for libraries, not apps

  • Python, bash, et. al. - Via the Scripting Environment

  • Corona- One is to use the Corona SDK . Corona is a high level SDK built on the Lua programming language. Lua is much simpler to learn than Java and the SDK takes away a lot of the pain in developing Android app.

  • Cordova - which uses HTML5, JavaScript, CSS, and can be extended with Java

  • Xamarin technology - that uses c# and in which mono is used for that. Here MonoTouch and Mono for Android are cross-platform implementations of the Common Language Infrastructure (CLI) and Common Language Specifications.

As for your second question: android is highly dependent on it's java architecture, I find it unlikely that there will be other primary development languages available any time soon. However, there's no particular reason why someone couldn't implement another language in Java (something like Jython) and use that. However, that surely won't be easier or as performant as just writing the code in Java.

Check if null Boolean is true results in exception

Boolean is the object wrapper class for the primitive boolean. This class, as any class, can indeed be null. For performance and memory reasons it is always best to use the primitive.

The wrapper classes in the Java API serve two primary purposes:

  1. To provide a mechanism to “wrap” primitive values in an object so that the primitives can be included in activities reserved for objects, like as being added to Collections, or returned from a method with an object return value.
  2. To provide an assortment of utility functions for primitives. Most of these functions are related to various conversions: converting primitives to and from String objects, and converting primitives and String objects to and from different bases (or radix), such as binary, octal, and hexadecimal.

http://en.wikipedia.org/wiki/Primitive_wrapper_class

Working with dictionaries/lists in R

To extend a little bit answer of Calimo I present few more things you may find useful while creating this quasi dictionaries in R:

a) how to return all the VALUES of the dictionary:

>as.numeric(foo)
[1] 12 22 33

b) check whether dictionary CONTAINS KEY:

>'tic' %in% names(foo)
[1] TRUE

c) how to ADD NEW key, value pair to dictionary:

c(foo,tic2=44)

results:

tic       tac       toe     tic2
12        22        33        44 

d) how to fulfill the requirement of REAL DICTIONARY - that keys CANNOT repeat(UNIQUE KEYS)? You need to combine b) and c) and build function which validates whether there is such key, and do what you want: e.g don't allow insertion, update value if the new differs from the old one, or rebuild somehow key(e.g adds some number to it so it is unique)

e) how to DELETE pair BY KEY from dictionary:

foo<-foo[which(foo!=foo[["tac"]])]

How can I convert a string to upper- or lower-case with XSLT?

In XSLT 1.0 the upper-case() and lower-case() functions are not available. If you're using a 1.0 stylesheet the common method of case conversion is translate():

<xsl:variable name="lowercase" select="'abcdefghijklmnopqrstuvwxyz'" />
<xsl:variable name="uppercase" select="'ABCDEFGHIJKLMNOPQRSTUVWXYZ'" />


<xsl:template match="/">
  <xsl:value-of select="translate(doc, $lowercase, $uppercase)" />
</xsl:template>

Why am I getting "IndentationError: expected an indented block"?

As the error message indicates, you have an indentation error. It is probably caused by a mix of tabs and spaces.

Getting Date or Time only from a DateTime Object

Sometimes you want to have your GridView as simple as:

  <asp:GridView ID="grid" runat="server" />

You don't want to specify any BoundField, you just want to bind your grid to DataReader. The following code helped me to format DateTime in this situation.

protected void Page_Load(object sender, EventArgs e)
{
  grid.RowDataBound += grid_RowDataBound;
  // Your DB access code here...
  // grid.DataSource = cmd.ExecuteReader(CommandBehavior.CloseConnection);
  // grid.DataBind();
}

void grid_RowDataBound(object sender, GridViewRowEventArgs e)
{
  if (e.Row.RowType != DataControlRowType.DataRow)
    return;
  var dt = (e.Row.DataItem as DbDataRecord).GetDateTime(4);
  e.Row.Cells[4].Text = dt.ToString("dd.MM.yyyy");
}

The results shown here. DateTime Formatting

Using numpy to build an array of all combinations of two arrays

itertools.combinations is in general the fastest way to get combinations from a Python container (if you do in fact want combinations, i.e., arrangements WITHOUT repetitions and independent of order; that's not what your code appears to be doing, but I can't tell whether that's because your code is buggy or because you're using the wrong terminology).

If you want something different than combinations perhaps other iterators in itertools, product or permutations, might serve you better. For example, it looks like your code is roughly the same as:

for val in itertools.product(np.arange(0, 1, 0.1), repeat=6):
    print F(val)

All of these iterators yield tuples, not lists or numpy arrays, so if your F is picky about getting specifically a numpy array you'll have to accept the extra overhead of constructing or clearing and re-filling one at each step.

How to load local file in sc.textFile, instead of HDFS

This has been discussed into spark mailing list, and please refer this mail.

You should use hadoop fs -put <localsrc> ... <dst> copy the file into hdfs:

${HADOOP_COMMON_HOME}/bin/hadoop fs -put /path/to/README.md README.md

Command Prompt Error 'C:\Program' is not recognized as an internal or external command, operable program or batch file

This seems to happen from time to time with programs that are very sensitive to command lines, but one option is to just use the DOS path instead of the Windows path. This means that C:\Program Files\ would resolve to C:\PROGRA~1\ and generally avoid any issues with spacing.

To get the short path you can create a quick Batch file that echos the short path:

@ECHO OFF
echo %~s1

Which is then called as follows:

C:\>shortPath.bat "C:\Program Files"
C:\PROGRA~1

How to iterate (keys, values) in JavaScript?

Try this:

var value;
for (var key in dictionary) {
    value = dictionary[key];
    // your code here...
}

Best way to work with transactions in MS SQL Server Management Studio

I want to add a point that you can also (and should if what you are writing is complex) add a test variable to rollback if you are in test mode. Then you can execute the whole thing at once. Often I also add code to see the before and after results of various operations especially if it is a complex script.

Example below:

USE AdventureWorks;
GO
DECLARE @TEST INT = 1--1 is test mode, use zero when you are ready to execute
BEGIN TRANSACTION;

BEGIN TRY
     IF @TEST= 1
        BEGIN
            SELECT *FROM Production.Product
                WHERE ProductID = 980;
        END    
    -- Generate a constraint violation error.
    DELETE FROM Production.Product
    WHERE ProductID = 980;

     IF @TEST= 1
        BEGIN
            SELECT *FROM Production.Product
                WHERE ProductID = 980;
            IF @@TRANCOUNT > 0
                ROLLBACK TRANSACTION;
        END    
END TRY

BEGIN CATCH
    SELECT 
        ERROR_NUMBER() AS ErrorNumber
        ,ERROR_SEVERITY() AS ErrorSeverity
        ,ERROR_STATE() AS ErrorState
        ,ERROR_PROCEDURE() AS ErrorProcedure
        ,ERROR_LINE() AS ErrorLine
        ,ERROR_MESSAGE() AS ErrorMessage;

    IF @@TRANCOUNT > 0
        ROLLBACK TRANSACTION;
END CATCH;

IF @@TRANCOUNT > 0 AND @TEST = 0
    COMMIT TRANSACTION;
GO

What is the best way to declare global variable in Vue.js?

I strongly recommend taking a look at Vuex, it is made for globally accessible data in Vue.

If you only need a few base variables that will never be modified, I would use ES6 imports:

// config.js
export default {
   hostname: 'myhostname'
}

// .vue file
import config from 'config.js'

console.log(config.hostname)

You could also import a json file in the same way, which can be edited by people without code knowledge or imported into SASS.

C++ terminate called without an active exception

Eric Leschinski and Bartosz Milewski have given the answer already. Here, I will try to present it in a more beginner friendly manner.

Once a thread has been started within a scope (which itself is running on a thread), one must explicitly ensure one of the following happens before the thread goes out of scope:

  • The runtime exits the scope, only after that thread finishes executing. This is achieved by joining with that thread. Note the language, it is the outer scope that joins with that thread.
  • The runtime leaves the thread to run on its own. So, the program will exit the scope, whether this thread finished executing or not. This thread executes and exits by itself. This is achieved by detaching the thread. This could lead to issues, for example, if the thread refers to variables in that outer scope.

Note, by the time the thread is joined with or detached, it may have well finished executing. Still either of the two operations must be performed explicitly.

Unable to execute dex: Multiple dex files define

For me the issue was that, i had added a lib project(autobahn lib) earlier and later switched the to Jar file of the same library.Though i had removed references to the older library project, i was getting this error. Following all the answers here i checked the build path etc. But i haven't added these libs to build path manually. So i had nothing to remove. Finally came across this folder.

bin/dexedLibs

I noticed that there were two jar files with the same name corresponding to autobahn Android which was causing the conflict. So i deleted all the jar files in the dexedLibs folder and rebuild the project. That resolved the issue.

Capture the screen shot using .NET

It's certainly possible to grab a screenshot using the .NET Framework. The simplest way is to create a new Bitmap object and draw into that using the Graphics.CopyFromScreen method.

Sample code:

using (Bitmap bmpScreenCapture = new Bitmap(Screen.PrimaryScreen.Bounds.Width, 
                                            Screen.PrimaryScreen.Bounds.Height))
using (Graphics g = Graphics.FromImage(bmpScreenCapture))
{
    g.CopyFromScreen(Screen.PrimaryScreen.Bounds.X,
                     Screen.PrimaryScreen.Bounds.Y,
                     0, 0,
                     bmpScreenCapture.Size,
                     CopyPixelOperation.SourceCopy);
}

Caveat: This method doesn't work properly for layered windows. Hans Passant's answer here explains the more complicated method required to get those in your screen shots.

How to check if a python module exists without importing it

A simpler if statement from AskUbuntu: How do I check whether a module is installed in Python?

import sys
print('eggs' in sys.modules)

Android. Fragment getActivity() sometimes returns null

It seems that I found a solution to my problem. Very good explanations are given here and here. Here is my example:

pulic class MyActivity extends FragmentActivity{

private ViewPager pager; 
private TitlePageIndicator indicator;
private TabsAdapter adapter;
private Bundle savedInstanceState;

 @Override
public void onCreate(Bundle savedInstanceState) {

    .... 
    this.savedInstanceState = savedInstanceState;
    pager = (ViewPager) findViewById(R.id.pager);;
    indicator = (TitlePageIndicator) findViewById(R.id.indicator);
    adapter = new TabsAdapter(getSupportFragmentManager(), false);

    if (savedInstanceState == null){    
        adapter.addFragment(new FirstFragment());
        adapter.addFragment(new SecondFragment());
    }else{
        Integer  count  = savedInstanceState.getInt("tabsCount");
        String[] titles = savedInstanceState.getStringArray("titles");
        for (int i = 0; i < count; i++){
            adapter.addFragment(getFragment(i), titles[i]);
        }
    }


    indicator.notifyDataSetChanged();
    adapter.notifyDataSetChanged();

    // push first task
    FirstTask firstTask = new FirstTask(MyActivity.this);
    // set first fragment as listener
    firstTask.setTaskListener((TaskListener) getFragment(0));
    firstTask.execute();

}

private Fragment getFragment(int position){
     return savedInstanceState == null ? adapter.getItem(position) : getSupportFragmentManager().findFragmentByTag(getFragmentTag(position));
}

private String getFragmentTag(int position) {
    return "android:switcher:" + R.id.pager + ":" + position;
}

 @Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putInt("tabsCount",      adapter.getCount());
    outState.putStringArray("titles", adapter.getTitles().toArray(new String[0]));
}

 indicator.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageSelected(int position) {
            Fragment currentFragment = adapter.getItem(position);
            ((Taskable) currentFragment).executeTask();
        }

        @Override
        public void onPageScrolled(int i, float v, int i1) {}

        @Override
        public void onPageScrollStateChanged(int i) {}
 });

The main idea in this code is that, while running your application normally, you create new fragments and pass them to the adapter. When you are resuming your application fragment manager already has this fragment's instance and you need to get it from fragment manager and pass it to the adapter.

UPDATE

Also, it is a good practice when using fragments to check isAdded before getActivity() is called. This helps avoid a null pointer exception when the fragment is detached from the activity. For example, an activity could contain a fragment that pushes an async task. When the task is finished, the onTaskComplete listener is called.

@Override
public void onTaskComplete(List<Feed> result) {

    progress.setVisibility(View.GONE);
    progress.setIndeterminate(false);
    list.setVisibility(View.VISIBLE);

    if (isAdded()) {

        adapter = new FeedAdapter(getActivity(), R.layout.feed_item, result);
        list.setAdapter(adapter);
        adapter.notifyDataSetChanged();
    }

}

If we open the fragment, push a task, and then quickly press back to return to a previous activity, when the task is finished, it will try to access the activity in onPostExecute() by calling the getActivity() method. If the activity is already detached and this check is not there:

if (isAdded()) 

then the application crashes.