Programs & Examples On #Jtextpane

A Java Swing text component that can be marked up with attributes that are represented graphically.

Is Tomcat running?

Create a Shell script that checks if tomcat is up or down and set a cron for sh to make it check every few minutes, and auto start tomcat if down. Sample Snippet of code below

TOMCAT_PID=$(ps -ef | awk '/[t]omcat/{print $2}')
echo TOMCAT PROCESSID $TOMCAT_PID

if [ -z "$TOMCAT_PID" ]
then
    echo "TOMCAT NOT RUNNING"
    sudo /opt/tomcat/bin/startup.sh
else
   echo "TOMCAT RUNNING"
fi

CSS two div width 50% in one line with line break in file

The problem you run into when setting width to 50% is the rounding of subpixels. If the width of your container is i.e. 99 pixels, a width of 50% can result in 2 containers of 50 pixels each.

Using float is probably easiest, and not such a bad idea. See this question for more details on how to fix the problem then.

If you don't want to use float, try using a width of 49%. This will work cross-browser as far as I know, but is not pixel-perfect..

html:

<div id="a">A</div>
<div id="b">B</div>

css:

#a, #b {
    width: 49%;
    display: inline-block; 
}
#a {background-color: red;}
#b {background-color: blue;}

Visual Studio 2015 doesn't have cl.exe

Visual Studio 2015 doesn't install C++ by default. You have to rerun the setup, select Modify and then check Programming Language -> C++

best way to create object

Or you can use a data file to put many person objects in to a list or array. You do need to use the System.IO for this. And you need a data file which contains all the information about the objects.

A method for it would look something like this:

static void ReadFile()
{
    using(StreamWriter writer = new StreamWriter(@"Data.csv"))
    {
        string line = null;
        line = reader.ReadLine();
        while(null!= (line = reader.ReadLine())
                {
                    string[] values = line.Split(',');
                    string name = values[0];
                    int age = int.Parse(values[1]);
                }
        Person person = new Person(name, age);
    }
}

How to use youtube-dl from a python program?

I would like this

from subprocess import call

command = "youtube-dl https://www.youtube.com/watch?v=NG3WygJmiVs -c"
call(command.split(), shell=False)

NSString with \n or line break

NSString *str1 = @"Share Role Play Photo via Facebook, or Twitter for free coins per photo.";
NSString *str2 = @"Like Role Play on facebook for 50 free coins.";
NSString *str3 = @"Check out 'What's Hot' on other ways to receive free coins";


NSString *msg = [NSString stringWithFormat:@"%@\n%@\n%@", str1, str2, str3];

Pandas rename column by position?

try this

df.rename(columns={ df.columns[1]: "your value" }, inplace = True)

Get current scroll position of ScrollView in React Native

As for the page, I'm working on a higher order component that uses basically the above methods to do exactly this. It actually takes just a bit of time when you get down to the subtleties like initial layout and content changes. I won't claim to have done it 'correctly', but in some sense I'd consider the correct answer to use component that does this carefully and consistently.

See: react-native-paged-scroll-view. Would love feedback, even if it's that I've done it all wrong!

How to override maven property in command line?

See Introduction to the POM

finalName is created as:

<build>
    <finalName>${project.artifactId}-${project.version}</finalName>
</build>

One of the solutions is to add own property:

<properties>
    <finalName>${project.artifactId}-${project.version}</finalName>
</properties>
<build>
    <finalName>${finalName}</finalName>
 </build>

And now try:

mvn -DfinalName=build clean package

How do I make an Android EditView 'Done' button and hide the keyboard when clicked?

Kotlin Solution

The direct way to handle the hide keyboard + done action in Kotlin is:

// Set action
edittext.setOnEditorActionListener { _, actionId, _ ->
    if (actionId == EditorInfo.IME_ACTION_DONE) {
        // Hide Keyboard
        val inputMethodManager = context.getSystemService(INPUT_METHOD_SERVICE) as InputMethodManager
        inputMethodManager.hideSoftInputFromWindow(windowToken, 0)
        true
    }
    false
}

Kotlin Extension

Use this to call edittext.onDone {/*action*/} in your main code. Keeps it more readable and maintainable

edittext.onDone { edittext.hideKeyboard() }

fun View.hideKeyboard() {
    val inputMethodManager = context.getSystemService(INPUT_METHOD_SERVICE) as InputMethodManager
    inputMethodManager.hideSoftInputFromWindow(windowToken, 0)
}

fun EditText.onDone(callback: () -> Unit) {
    // These lines optional if you don't want to set in Xml
    imeOptions = EditorInfo.IME_ACTION_DONE
    maxLines = 1
    setOnEditorActionListener { _, actionId, _ ->
        if (actionId == EditorInfo.IME_ACTION_DONE) {
            callback.invoke()
            true
        }
        false
    }
}

Additional Keyboard Extensions

If you'd like more ways to simplify working with the keyboard (show, close, focus): Read this post

Don't forget to add these options to your edittext Xml, if not in code

<EditText ...
    android:imeOptions="actionDone"
    android:inputType="text"/>

Need inputType="textMultiLine" support? Read this post and don't add imeOptions or inputType in Xml

Javascript can't find element by id?

Script is called before element exists.

You should try one of the following:

  1. wrap code into a function and use a body onload event to call it.
  2. put script at the end of document
  3. use defer attribute into script tag declaration

Access to file download dialog in Firefox

In addition you can add

      profile.setPreference("browser.download.panel.shown",false);

To remove the downloaded file list that gets shown by default and covers up part of the web page.

My total settings are:

        DesiredCapabilities dc = DesiredCapabilities.firefox();
        dc.merge(capabillities);
        FirefoxProfile profile = new FirefoxProfile();
        profile.setAcceptUntrustedCertificates(true);
        profile.setPreference("browser.download.folderList", 4);
        profile.setPreference("browser.download.dir", TestConstants.downloadDir.getAbsolutePath());
        profile.setPreference("browser.download.manager.alertOnEXEOpen", false);
        profile.setPreference("browser.helperApps.neverAsk.saveToDisk", "application/msword, application/csv, application/ris, text/csv, data:image/png, image/png, application/pdf, text/html, text/plain, application/zip, application/x-zip, application/x-zip-compressed, application/download, application/octet-stream");
        profile.setPreference("browser.download.manager.showWhenStarting", false);
        profile.setPreference("browser.download.manager.focusWhenStarting", false);
        profile.setPreference("browser.download.useDownloadDir", true);
        profile.setPreference("browser.helperApps.alwaysAsk.force", false);
        profile.setPreference("browser.download.manager.alertOnEXEOpen", false);
        profile.setPreference("browser.download.manager.closeWhenDone", true);
        profile.setPreference("browser.download.manager.showAlertOnComplete", false);
        profile.setPreference("browser.download.manager.useWindow", false);
        profile.setPreference("browser.download.panel.shown",false);
        dc.setCapability(FirefoxDriver.PROFILE, profile);
        this.driver = new FirefoxDriver(dc);

How to access the php.ini file in godaddy shared hosting linux

Not php.ini file, but a way around it. Go to GoDaddy's

Files > Backup > Restore a MySQL Database Backup

Choose your file and click Upload. No timeouts. Rename the DB if needed, and assign a user in

Databases > MySQL Databases

Rails - controller action name to string

controller name:

<%= controller.controller_name %>

return => 'users'

action name:

<%= controller.action_name %>

return => 'show'

id:

<%= ActionController::Routing::Routes.recognize_path(request.url)[:id] %>

return => '23'

Convert integer value to matching Java Enum

You could add a static method in your enum that accepts an int as a parameter and returns a PcapLinkType.

public static PcapLinkType of(int linkType) {

    switch (linkType) {
        case -1: return DLT_UNKNOWN
        case 0: return DLT_NULL;

        //ETC....

        default: return null;

    }
}

How to refresh Gridview after pressed a button in asp.net

I was totally lost on why my Gridview.Databind() would not refresh.

My issue, I discovered, was my gridview was inside a UpdatePanel. To get my GridView to FINALLY refresh was this:

gvServerConfiguration.Databind()
uppServerConfiguration.Update()

uppServerConfiguration is the id associated with my UpdatePanel in my asp.net code.

Hope this helps someone.

How to include Authorization header in cURL POST HTTP Request in PHP?

You have most of the code…

CURLOPT_HTTPHEADER for curl_setopt() takes an array with each header as an element. You have one element with multiple headers.

You also need to add the Authorization header to your $header array.

$header = array();
$header[] = 'Content-length: 0';
$header[] = 'Content-type: application/json';
$header[] = 'Authorization: OAuth SomeHugeOAuthaccess_tokenThatIReceivedAsAString';

-bash: export: `=': not a valid identifier

First of all go to the /home directorty then open invisible shell script with some text editor, ~/.bash_profile (macOS) or ~/.bashrc (linux) go to the bottom, you would see something like this,

export LD_LIBRARY_PATH = /usr/local/lib

change this like that( remove blank point around the = ),

export LD_LIBRARY_PATH=/usr/local/lib

it should be useful.

adb remount permission denied, but able to access super user in shell -- android

In case anyone has the same problem in the future:

$ adb shell
$ su
# mount -o rw,remount /system

Both adb remount and adb root don't work on a production build without altering ro.secure, but you can still remount /system by opening a shell, asking for root permissions and typing the mount command.

CSS image overlay with color and transparency

If you want to make the reverse of what you showed consider doing this:

.tint:hover:before {
    background: rgba(0,0,250, 0.5);

  }

  .t2:before {
    background: none;
  }

and look at the effect on the 2nd picture.

Is it supposed to look like this?

Github Push Error: RPC failed; result=22, HTTP code = 413

Was facing same issue. In my case it was non-compatible GIT versions across multiple users who are accessing(pull/push) same project.

have just updated GIT version and updated the path on Android studio settings and its working fine for me.

Edit -

Git for Windows (1.9.5) having some problem, updating the same may helps.

Dialog to pick image from gallery or from camera

I have merged some solutions to make a complete util for picking an image from Gallery or Camera. These are the features of ImagePicker util gist (also in a Github lib):

  • Merged intents for Gallery and Camera resquests.
  • Resize selected big images (e.g.: 2500 x 1600)
  • Rotate image if necesary

Screenshot:

ImagePicker starting intent

Edit: Here is a fragment of code to get a merged Intent for Gallery and Camera apps together. You can see the full code at ImagePicker util gist (also in a Github lib):

public static Intent getPickImageIntent(Context context) {
    Intent chooserIntent = null;

    List<Intent> intentList = new ArrayList<>();

    Intent pickIntent = new Intent(Intent.ACTION_PICK,
            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    Intent takePhotoIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    takePhotoIntent.putExtra("return-data", true);
    takePhotoIntent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(getTempFile(context)));
    intentList = addIntentsToList(context, intentList, pickIntent);
    intentList = addIntentsToList(context, intentList, takePhotoIntent);

    if (intentList.size() > 0) {
        chooserIntent = Intent.createChooser(intentList.remove(intentList.size() - 1),
                context.getString(R.string.pick_image_intent_text));
        chooserIntent.putExtra(Intent.EXTRA_INITIAL_INTENTS, intentList.toArray(new Parcelable[]{}));
    }

    return chooserIntent;
}

private static List<Intent> addIntentsToList(Context context, List<Intent> list, Intent intent) {
    List<ResolveInfo> resInfo = context.getPackageManager().queryIntentActivities(intent, 0);
    for (ResolveInfo resolveInfo : resInfo) {
        String packageName = resolveInfo.activityInfo.packageName;
        Intent targetedIntent = new Intent(intent);
        targetedIntent.setPackage(packageName);
        list.add(targetedIntent);
    }
    return list;
}

How to split one string into multiple strings separated by at least one space in bash shell?

I like the conversion to an array, to be able to access individual elements:

sentence="this is a story"
stringarray=($sentence)

now you can access individual elements directly (it starts with 0):

echo ${stringarray[0]}

or convert back to string in order to loop:

for i in "${stringarray[@]}"
do
  :
  # do whatever on $i
done

Of course looping through the string directly was answered before, but that answer had the the disadvantage to not keep track of the individual elements for later use:

for i in $sentence
do
  :
  # do whatever on $i
done

See also Bash Array Reference.

make image( not background img) in div repeat?

(DEMO)
Codes:

.backimage {width:99%;  height:98%;  position:absolute;    background:transparent url("http://upload.wikimedia.org/wikipedia/commons/4/41/Brickwall_texture.jpg") repeat scroll 0% 0%;  }

and

<div>
    <div class="backimage"></div>
    YOUR OTHER CONTENTTT
</div>

How can I execute PHP code from the command line?

You can use:

 echo '<?php if(function_exists("my_func")) echo "function exists"; ' | php

The short tag "< ?=" can be helpful too:

 echo '<?= function_exists("foo") ? "yes" : "no";' | php
 echo '<?= 8+7+9 ;' | php

The closing tag "?>" is optional, but don't forget the final ";"!

Allow multiple roles to access controller action

Using AspNetCore 2.x, you have to go a little different way:

[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class, Inherited = true, AllowMultiple = true)]
public class AuthorizeRoleAttribute : AuthorizeAttribute
{
    public AuthorizeRoleAttribute(params YourEnum[] roles)
    {
        Policy = string.Join(",", roles.Select(r => r.GetDescription()));
    }
}

just use it like this:

[Authorize(YourEnum.Role1, YourEnum.Role2)]

HashSet vs. List performance

Depends on what you're hashing. If your keys are integers you probably don't need very many items before the HashSet is faster. If you're keying it on a string then it will be slower, and depends on the input string.

Surely you could whip up a benchmark pretty easily?

Compilation error: stray ‘\302’ in program etc

You have an invalid character on that line. This is what I saw:

enter image description here

Call an angular function inside html

Yep, just add parenthesis (calling the function). Make sure the function is in scope and actually returns something.

<ul class="ui-listview ui-radiobutton" ng-repeat="meter in meters">
  <li class = "ui-divider">
    {{ meter.DESCRIPTION }}
    {{ htmlgeneration() }}
  </li>
</ul>

Getting windbg without the whole WDK?

For Windows 7 x86 you can also download the ISO: http://www.microsoft.com/en-us/download/confirmation.aspx?id=8442

And run \Setup\WinSDKDebuggingTools\dbg_x86.msi

WinDbg.exe will then be installed (default location) to: C:\Program Files (x86)\Debugging Tools for Windows (x86)

Iterate over elements of List and Map using JSTL <c:forEach> tag

try this

<c:forEach items="${list}" var="map">
    <tr>
        <c:forEach items="${map}" var="entry">

            <td>${entry.value}</td>

        </c:forEach>
    </tr>
</c:forEach>

BSTR to std::string (std::wstring) and vice versa

Simply pass the BSTR directly to the wstring constructor, it is compatible with a wchar_t*:

BSTR btest = SysAllocString(L"Test");
assert(btest != NULL);
std::wstring wtest(btest);
assert(0 == wcscmp(wtest.c_str(), btest));

Converting BSTR to std::string requires a conversion to char* first. That's lossy since BSTR stores a utf-16 encoded Unicode string. Unless you want to encode in utf-8. You'll find helper methods to do this, as well as manipulate the resulting string, in the ICU library.

Android: adb: Permission Denied

You might need to activate adb root from the developer settings menu. If you run adb root from the cmd line you can get:

root access is disabled by system setting - enable in settings -> development options

Once you activate the root option (ADB only or Apps and ADB) adb will restart and you will be able to use root from the cmd line.

Get names of all files from a folder with Ruby

You also have the shortcut option of

Dir["/path/to/search/*"]

and if you want to find all Ruby files in any folder or sub-folder:

Dir["/path/to/search/**/*.rb"]

Change DIV content using ajax, php and jQuery

<script>
$(function(){
    $('.movie').click(function(){
        var this_href=$(this).attr('href');
        $.ajax({
            url:this_href,
            type:'post',
            cache:false,
            success:function(data)
            {
                $('#summary').html(data);
            }
        });
        return false;
    });
});
</script>

Embed YouTube Video with No Ads

If you play the video as a playlist and then single out that video you can get it without ads. Here is what I have done: https://www.youtube.com/v/VIDEO_ID?playlist=VIDEO_ID&autoplay=1&rel=0

Run "mvn clean install" in Eclipse

Right click on pom.xml, Run As, you should see the list of m2 options if you have Maven installed, you can select Maven Clean from there

"Conversion to Dalvik format failed with error 1" on external JAR

Nothing helped me, but the suggested solution here worked like a charm:

i.e. adding the line -optimizations !code/allocation/variable to proguard-project.txt

How to use Jquery how to change the aria-expanded="false" part of a dom element (Bootstrap)?

You can use .attr() as a part of however you plan to toggle it:

$("button").attr("aria-expanded","true");

Java check to see if a variable has been initialized

Assuming you're interested in whether the variable has been explicitly assigned a value or not, the answer is "not really". There's absolutely no difference between a field (instance variable or class variable) which hasn't been explicitly assigned at all yet, and one which has been assigned its default value - 0, false, null etc.

Now if you know that once assigned, the value will never reassigned a value of null, you can use:

if (box != null) {
    box.removeFromCanvas();
}

(and that also avoids a possible NullPointerException) but you need to be aware that "a field with a value of null" isn't the same as "a field which hasn't been explicitly assigned a value". Null is a perfectly valid variable value (for non-primitive variables, of course). Indeed, you may even want to change the above code to:

if (box != null) {
    box.removeFromCanvas();
    // Forget about the box - we don't want to try to remove it again
    box = null;
}

The difference is also visible for local variables, which can't be read before they've been "definitely assigned" - but one of the values which they can be definitely assigned is null (for reference type variables):

// Won't compile
String x;
System.out.println(x);

// Will compile, prints null
String y = null;
System.out.println(y);

NoSQL Use Case Scenarios or WHEN to use NoSQL

I think Nosql is "more suitable" in these scenarios at least (more supplementary is welcome)

  1. Easy to scale horizontally by just adding more nodes.

  2. Query on large data set

    Imagine tons of tweets posted on twitter every day. In RDMS, there could be tables with millions (or billions?) of rows, and you don't want to do query on those tables directly, not even mentioning, most of time, table joins are also needed for complex queries.

  3. Disk I/O bottleneck

    If a website needs to send results to different users based on users' real-time info, we are probably talking about tens or hundreds of thousands of SQL read/write requests per second. Then disk i/o will be a serious bottleneck.

Only one expression can be specified in the select list when the subquery is not introduced with EXISTS

It's complaining about

COUNT(DISTINCT dNum) AS ud 

inside the subquery. Only one column can be returned from the subquery unless you are performing an exists query. I'm not sure why you want to do a count on the same column twice, superficially it looks redundant to what you are doing. The subquery here is only a filter it is not the same as a join. i.e. you use it to restrict data, not to specify what columns to get back.

What's the purpose of SQL keyword "AS"?

If you design query using the Query editor in SQL Server 2012 for example you would get this:

  SELECT        e.EmployeeID, s.CompanyName, o.ShipName
FROM            Employees AS e INNER JOIN
                         Orders AS o ON e.EmployeeID = o.EmployeeID INNER JOIN
                         Shippers AS s ON o.ShipVia = s.ShipperID
WHERE        (s.CompanyName = 'Federal Shipping')

However removing the AS does not make any difference as in the following:

 SELECT        e.EmployeeID, s.CompanyName, o.ShipName
FROM            Employees e INNER JOIN
                         Orders o ON e.EmployeeID = o.EmployeeID INNER JOIN
                         Shippers s ON o.ShipVia = s.ShipperID
WHERE        (s.CompanyName = 'Federal Shipping')

In this case use of AS is superfluous but in many other places it is needed.

Add text at the end of each line

Using a text editor, check for ^M (control-M, or carriage return) at the end of each line. You will need to remove them first, then append the additional text at the end of the line.

sed -i 's|^M||g' ips.txt
sed -i 's|$|:80|g' ips.txt

Select elements by attribute

$("input#A").attr("myattr") == null

await vs Task.Wait - Deadlock?

Wait and await - while similar conceptually - are actually completely different.

Wait will synchronously block until the task completes. So the current thread is literally blocked waiting for the task to complete. As a general rule, you should use "async all the way down"; that is, don't block on async code. On my blog, I go into the details of how blocking in asynchronous code causes deadlock.

await will asynchronously wait until the task completes. This means the current method is "paused" (its state is captured) and the method returns an incomplete task to its caller. Later, when the await expression completes, the remainder of the method is scheduled as a continuation.

You also mentioned a "cooperative block", by which I assume you mean a task that you're Waiting on may execute on the waiting thread. There are situations where this can happen, but it's an optimization. There are many situations where it can't happen, like if the task is for another scheduler, or if it's already started or if it's a non-code task (such as in your code example: Wait cannot execute the Delay task inline because there's no code for it).

You may find my async / await intro helpful.

Notepad++: Multiple words search in a file (may be in different lines)?

Possible solution

  1. In Notepad++ , click search menu, the click Find
  2. in FIND WHAT : enter this ==> cat|town
  3. Select REGULAR EXPRESSION radiobutton
  4. click FIND IN CURRENT DOCUMENT

Screenshot

What are access specifiers? Should I inherit with private, protected or public?

The explanation from Scott Meyers in Effective C++ might help understand when to use them:

Public inheritance should model "is-a relationship," whereas private inheritance should be used for "is-implemented-in-terms-of" - so you don't have to adhere to the interface of the superclass, you're just reusing the implementation.

How to zero pad a sequence of integers in bash so that all have the same width?

Easier still you can just do

for i in {00001..99999}; do
  echo $i
done

MySQL: Insert datetime into other datetime field

Try

    UPDATE products SET former_date=20111218131717 WHERE id=1

Alternatively, you might want to look at using the STR_TO_DATE (see STR_TO_DATE(str,format)) function.

How to get current date in jquery?

You can do this:

    var now = new Date();
    dateFormat(now, "dddd, mmmm dS, yyyy, h:MM:ss TT");
     // Saturday, June 9th, 2007, 5:46:21 PM

OR Something like

    var dateObj = new Date();
    var month = dateObj.getUTCMonth();
    var day = dateObj.getUTCDate();
    var year = dateObj.getUTCFullYear();
    var newdate = month + "/" + day + "/" + year;
    alert(newdate);

This Activity already has an action bar supplied by the window decor

I got this error due to a custome attribute inside, removing it fixed the issue.

    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
..
        <item name="searchBarBgColor">#383838</item>  --> remove this line
    </style>

Adding calculated column(s) to a dataframe in pandas

The first four functions you list will work on vectors as well, with the exception that lower_wick needs to be adapted. Something like this,

def lower_wick_vec(o, l, c):
    min_oc = numpy.where(o > c, c, o)
    return min_oc - l

where o, l and c are vectors. You could do it this way instead which just takes the df as input and avoid using numpy, although it will be much slower:

def lower_wick_df(df):
    min_oc = df[['Open', 'Close']].min(axis=1)
    return min_oc - l

The other three will work on columns or vectors just as they are. Then you can finish off with

def is_hammer(df):
    lw = lower_wick_at_least_twice_real_body(df["Open"], df["Low"], df["Close"]) 
    cl = closed_in_top_half_of_range(df["High"], df["Low"], df["Close"])
    return cl & lw

Bit operators can perform set logic on boolean vectors, & for and, | for or etc. This is enough to completely vectorize the sample calculations you gave and should be relatively fast. You could probably speed up even more by temporarily working with the numpy arrays underlying the data while performing these calculations.

For the second part, I would recommend introducing a column indicating the pattern for each row and writing a family of functions which deal with each pattern. Then groupby the pattern and apply the appropriate function to each group.

Tomcat is not running even though JAVA_HOME path is correct

there are two types of environment variable first User variable if you path in this it will work for that particular user only. second is System variable if you set path in this it is used by all type of users.. In my system i set JAVA_HOME in system variable,it was not working,then i set path in User variable it is working.....so try in both type of environment variable...

The name 'controlname' does not exist in the current context

Also, make sure you have no files that accidentally try to inherit or define the same (partial) class as other files. Note that these files can seem unrelated to the files where the error actually appeared!

SQL Server 2005 Using DateAdd to add a day to a date

DECLARE @date DateTime
SET @date = GetDate()
SET @date = DateAdd(day, 1, @date)

SELECT @date

Unzip files programmatically in .net

Standard zip files normally use the deflate algorithm.

To extract files without using third party libraries use DeflateStream. You'll need a bit more information about the zip file archive format as Microsoft only provides the compression algorithm.

You may also try using zipfldr.dll. It is Microsoft's compression library (compressed folders from the Send to menu). It appears to be a com library but it's undocumented. You may be able to get it working for you through experimentation.

How to remove element from ArrayList by checking its value?

You would need to use an Iterator like so:

Iterator<String> iterator = a.iterator();
while(iterator.hasNext())
{
    String value = iterator.next();
    if ("abcd".equals(value))
    {
        iterator.remove();
        break;
    }
}

That being said, you can use the remove(int index) or remove(Object obj) which are provided by the ArrayList class. Note however, that calling these methods while you are iterating over the loop, will cause a ConcurrentModificationException, so this will not work:

for(String str : a)
{
    if (str.equals("acbd")
    {
        a.remove("abcd");
        break;
    }
}

But this will (since you are not iterating over the contents of the loop):

a.remove("acbd");

If you have more complex objects you would need to override the equals method.

How to filter files when using scp to copy dir recursively?

I'd probably recommend using something like rsync for this due to its include and exclude flags, e.g:-

rsync -rav -e ssh --include '*/' --include='*.class' --exclude='*' \
server:/usr/some/unknown/number/of/sub/folders/ \ 
/usr/project/backup/some/unknown/number/of/sub/folders/

Some other useful flags:

  • -r for recursive
  • -a for archive (mostly all files)
  • -v for verbose output
  • -e to specify ssh instead of the default (which should be ssh, actually)

How can I generate a random number in a certain range?

Random Number Generator in Android If you want to know about random number generator in android then you should read this article till end. Here you can get all information about random number generator in android. Random Number Generator in Android

You should use this code in your java file.

Random r = new Random();
                    int randomNumber = r.nextInt(100);
                    tv.setText(String.valueOf(randomNumber));

I hope this answer may helpful for you. If you want to read more about this article then you should read this article. Random Number Generator

When to use RabbitMQ over Kafka?

I hear this question every week... While RabbitMQ (like IBM MQ or JMS or other messaging solutions in general) is used for traditional messaging, Apache Kafka is used as streaming platform (messaging + distributed storage + processing of data). Both are built for different use cases.

You can use Kafka for "traditional messaging", but not use MQ for Kafka-specific scenarios.

The article “Apache Kafka vs. Enterprise Service Bus (ESB)—Friends, Enemies, or Frenemies? (https://www.confluent.io/blog/apache-kafka-vs-enterprise-service-bus-esb-friends-enemies-or-frenemies/)” discusses why Kafka is not competitive but complementary to integration and messaging solutions (including RabbitMQ) and how to integrate both.

Work with a time span in Javascript

You can use momentjs duration object

Example:

const diff = moment.duration(Date.now() - new Date(2010, 1, 1))
console.log(`${diff.years()} years ${diff.months()} months ${diff.days()} days ${diff.hours()} hours ${diff.minutes()} minutes and ${diff.seconds()} seconds`)

Can inner classes access private variables?

Anything that is part of Outer should have access to all of Outer's members, public or private.

Edit: your compiler is correct, var is not a member of Inner. But if you have a reference or pointer to an instance of Outer, it could access that.

showing that a date is greater than current date

Select * from table where date > 'Today's date(mm/dd/yyyy)'

You can also add time in the single quotes(00:00:00AM)

For example:

Select * from Receipts where Sales_date > '08/28/2014 11:59:59PM'

Create Git branch with current changes

Since you haven't made any commits yet, you can save all your changes to the stash, create and switch to a new branch, then pop those changes back into your working tree:

git stash  # save local modifications to new stash
git checkout -b topic/newbranch
git stash pop  # apply stash and remove it from the stash list

Limit text length to n lines using CSS

.class{
   word-break: break-word;
   overflow: hidden;
   text-overflow: ellipsis;
   display: -webkit-box;
   line-height: 16px; /* fallback */
   max-height: 32px; /* fallback */
   -webkit-line-clamp: 2; /* number of lines to show */
   -webkit-box-orient: vertical;
}

use of entityManager.createNativeQuery(query,foo.class)

Suppose your query is "select id,name from users where rollNo = 1001".

Here query will return a object with id and name column. Your Response class is like bellow:

public class UserObject{
        int id;
        String name;
        String rollNo;

        public UserObject(Object[] columns) {
            this.id = (columns[0] != null)?((BigDecimal)columns[0]).intValue():0;
            this.name = (String) columns[1];
        }

        public int getId() {
            return id;
        }

        public void setId(int id) {
            this.id = id;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public String getRollNo() {
            return rollNo;
        }

        public void setRollNo(String rollNo) {
            this.rollNo = rollNo;
        }
    }

here UserObject constructor will get a Object Array and set data with object.

public UserObject(Object[] columns) {
            this.id = (columns[0] != null)?((BigDecimal)columns[0]).intValue():0;
            this.name = (String) columns[1];
        }

Your query executing function is like bellow :

public UserObject getUserByRoll(EntityManager entityManager,String rollNo) {

        String queryStr = "select id,name from users where rollNo = ?1";
        try {
            Query query = entityManager.createNativeQuery(queryStr);
            query.setParameter(1, rollNo);

            return new UserObject((Object[]) query.getSingleResult());
        } catch (Exception e) {
            e.printStackTrace();
            throw e;
        }
    }

Here you have to import bellow packages:

import javax.persistence.Query;
import javax.persistence.EntityManager;

Now your main class, you have to call this function. First you have to get EntityManager and call this getUserByRoll(EntityManager entityManager,String rollNo) function. Calling procedure is given bellow:

@PersistenceContext
private EntityManager entityManager;

UserObject userObject = getUserByRoll(entityManager,"1001");

Now you have data in this userObject.

Here is Imports

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

Note:

query.getSingleResult() return a array. You have to maintain the column position and data type.

select id,name from users where rollNo = ?1 

query return a array and it's [0] --> id and [1] -> name.

For more info, visit this Answer

Thanks :)

Importing a function from a class in another file?

It would really help if you'd include the code that's not working (from the 'other' file), but I suspect you could do what you want with a healthy dose of the 'eval' function.

For example:

def run():
    print "this does nothing"

def chooser():
    return "run"

def main():
    '''works just like:
    run()'''
    eval(chooser())()

The chooser returns the name of the function to execute, eval then turns a string into actual code to be executed in-place, and the parentheses finish off the function call.

NameError: name 'reduce' is not defined in Python

You can add

from functools import reduce

before you use the reduce.

Convert hexadecimal string (hex) to a binary string

import java.util.*;
public class HexadeciamlToBinary
{
   public static void main()
   {
       Scanner sc=new Scanner(System.in);
       System.out.println("enter the hexadecimal number");
       String s=sc.nextLine();
       String p="";
       long n=0;
       int c=0;
       for(int i=s.length()-1;i>=0;i--)
       {
          if(s.charAt(i)=='A')
          {
             n=n+(long)(Math.pow(16,c)*10);
             c++;
          }
         else if(s.charAt(i)=='B')
         {
            n=n+(long)(Math.pow(16,c)*11);
            c++;
         }
        else if(s.charAt(i)=='C')
        {
            n=n+(long)(Math.pow(16,c)*12);
            c++;
        }
        else if(s.charAt(i)=='D')
        {
           n=n+(long)(Math.pow(16,c)*13);
           c++;
        }
        else if(s.charAt(i)=='E')
        {
            n=n+(long)(Math.pow(16,c)*14);
            c++;
        }
        else if(s.charAt(i)=='F')
        {
            n=n+(long)(Math.pow(16,c)*15);
            c++;
        }
        else
        {
            n=n+(long)Math.pow(16,c)*(long)s.charAt(i);
            c++;
        }
    }
    String s1="",k="";
    if(n>1)
    {
    while(n>0)
    {
        if(n%2==0)
        {
            k=k+"0";
            n=n/2;
        }
        else
        {
            k=k+"1";
            n=n/2;
        }
    }
    for(int i=0;i<k.length();i++)
    {
        s1=k.charAt(i)+s1;
    }
    System.out.println("The respective binary number is : "+s1);
    }
    else
    {
        System.out.println("The respective binary number is : "+n);
    }
  }
}

Hibernate - A collection with cascade=”all-delete-orphan” was no longer referenced by the owning entity instance

Check all of the places where you are assigning something to sonEntities. The link you referenced distinctly points out creating a new HashSet but you can have this error anytime you reassign the set. For example:

public void setChildren(Set<SonEntity> aSet)
{
    this.sonEntities = aSet; //This will override the set that Hibernate is tracking.
}

Usually you want to only "new" the set once in a constructor. Any time you want to add or delete something to the list you have to modify the contents of the list instead of assigning a new list.

To add children:

public void addChild(SonEntity aSon)
{
    this.sonEntities.add(aSon);
}

To remove children:

public void removeChild(SonEntity aSon)
{
    this.sonEntities.remove(aSon);
}

Android: I am unable to have ViewPager WRAP_CONTENT

I just bumped into the same issue. I had a ViewPager and I wanted to display an ad at the button of it. The solution I found was to get the pager into a RelativeView and set it's layout_above to the view id i want to see below it. that worked for me.

here is my layout XML:

  <RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <LinearLayout
        android:id="@+id/AdLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:orientation="vertical" >
    </LinearLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/mainpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/AdLayout" >
    </android.support.v4.view.ViewPager>
</RelativeLayout>

How do I get the output of a shell command executed using into a variable from Jenkinsfile (groovy)?

The latest version of the pipeline sh step allows you to do the following;

// Git committer email
GIT_COMMIT_EMAIL = sh (
    script: 'git --no-pager show -s --format=\'%ae\'',
    returnStdout: true
).trim()
echo "Git committer email: ${GIT_COMMIT_EMAIL}"

Another feature is the returnStatus option.

// Test commit message for flags
BUILD_FULL = sh (
    script: "git log -1 --pretty=%B | grep '\\[jenkins-full]'",
    returnStatus: true
) == 0
echo "Build full flag: ${BUILD_FULL}"

These options where added based on this issue.

See official documentation for the sh command.

For declarative pipelines (see comments), you need to wrap code into script step:

script {
   GIT_COMMIT_EMAIL = sh (
        script: 'git --no-pager show -s --format=\'%ae\'',
        returnStdout: true
    ).trim()
    echo "Git committer email: ${GIT_COMMIT_EMAIL}"
}

.NET 4.0 has a new GAC, why?

I also wanted to know why 2 GAC and found the following explanation by Mark Miller in the comments section of .NET 4.0 has 2 Global Assembly Cache (GAC):

Mark Miller said... June 28, 2010 12:13 PM

Thanks for the post. "Interference issues" was intentionally vague. At the time of writing, the issues were still being investigated, but it was clear there were several broken scenarios.

For instance, some applications use Assemby.LoadWithPartialName to load the highest version of an assembly. If the highest version was compiled with v4, then a v2 (3.0 or 3.5) app could not load it, and the app would crash, even if there were a version that would have worked. Originally, we partitioned the GAC under it's original location, but that caused some problems with windows upgrade scenarios. Both of these involved code that had already shipped, so we moved our (version-partitioned GAC to another place.

This shouldn't have any impact to most applications, and doesn't add any maintenance burden. Both locations should only be accessed or modified using the native GAC APIs, which deal with the partitioning as expected. The places where this does surface are through APIs that expose the paths of the GAC such as GetCachePath, or examining the path of mscorlib loaded into managed code.

It's worth noting that we modified GAC locations when we released v2 as well when we introduced architecture as part of the assembly identity. Those added GAC_MSIL, GAC_32, and GAC_64, although all still under %windir%\assembly. Unfortunately, that wasn't an option for this release.

Hope it helps future readers.

Dictionary returning a default value if the key does not exist

I know this is an old post and I do favor extension methods, but here's a simple class I use from time to time to handle dictionaries when I need default values.

I wish this were just part of the base Dictionary class.

public class DictionaryWithDefault<TKey, TValue> : Dictionary<TKey, TValue>
{
  TValue _default;
  public TValue DefaultValue {
    get { return _default; }
    set { _default = value; }
  }
  public DictionaryWithDefault() : base() { }
  public DictionaryWithDefault(TValue defaultValue) : base() {
    _default = defaultValue;
  }
  public new TValue this[TKey key]
  {
    get { 
      TValue t;
      return base.TryGetValue(key, out t) ? t : _default;
    }
    set { base[key] = value; }
  }
}

Beware, however. By subclassing and using new (since override is not available on the native Dictionary type), if a DictionaryWithDefault object is upcast to a plain Dictionary, calling the indexer will use the base Dictionary implementation (throwing an exception if missing) rather than the subclass's implementation.

How do I print a double value with full precision using cout?

Here is how to display a double with full precision:

double d = 100.0000000000005;
int precision = std::numeric_limits<double>::max_digits10;
std::cout << std::setprecision(precision) << d << std::endl;

This displays:

100.0000000000005


max_digits10 is the number of digits that are necessary to uniquely represent all distinct double values. max_digits10 represents the number of digits before and after the decimal point.


Don't use set_precision(max_digits10) with std::fixed.
On fixed notation, set_precision() sets the number of digits only after the decimal point. This is incorrect as max_digits10 represents the number of digits before and after the decimal point.

double d = 100.0000000000005;
int precision = std::numeric_limits<double>::max_digits10;
std::cout << std::fixed << std::setprecision(precision) << d << std::endl;

This displays incorrect result:

100.00000000000049738

Note: Header files required

#include <iomanip>
#include <limits>

Capture Video of Android's Screen

If you are on a PC then you can run My Phone Explorer on the PC, the MyPhoneExplorer Client on the phone, set the screen capture to refresh continuously, and use Wink to capture a custom rectangular area of your screen over the My Phone Explorer window with your own capture rate. Then convert to a FLV in Wink, then convert from Flash video to MPG with WinFF.

Post an object as data using Jquery Ajax

[object Object] This means somewhere the object is being converted to a string.

Converted to a string:

//Copy and paste in the browser console to see result

var product = {'name':'test'};
JSON.stringify(product + ''); 

Not converted to a string:

//Copy and paste in the browser console to see result

var product = {'name':'test'};
JSON.stringify(product);

Bootstrap with jQuery Validation Plugin

I know this question is for Bootstrap 3, but as some Bootstrap 4 related question are redirected to this one as duplicates, here's the snippet Bootstrap 4-compatible:

$.validator.setDefaults({
    highlight: function(element) {
        $(element).closest('.form-group').addClass('has-danger');
    },
    unhighlight: function(element) {
        $(element).closest('.form-group').removeClass('has-danger');
    },
    errorElement: 'small',
    errorClass: 'form-control-feedback d-block',
    errorPlacement: function(error, element) {
        if(element.parent('.input-group').length) {
            error.insertAfter(element.parent());
        } else if(element.prop('type') === 'checkbox') {
            error.appendTo(element.parent().parent().parent());
        } else if(element.prop('type') === 'radio') {
            error.appendTo(element.parent().parent().parent());
        } else {
            error.insertAfter(element);
        }
    },
});

The few differences are:

  • The use of class has-danger instead of has-error
  • Better error positioning radios and checkboxes

Changing font size and direction of axes text in ggplot2

Using "fill" attribute helps in cases like this. You can remove the text from axis using element_blank()and show multi color bar chart with a legend. I am plotting a part removal frequency in a repair shop as below

ggplot(data=df_subset,aes(x=Part,y=Removal_Frequency,fill=Part))+geom_bar(stat="identity")+theme(axis.text.x  = element_blank())

I went for this solution in my case as I had many bars in bar chart and I was not able to find a suitable font size which is both readable and also small enough not to overlap each other.

Use a URL to link to a Google map with a marker on it

In May 2017 Google launched the official Google Maps URLs documentation. The Google Maps URLs introduces universal cross-platform syntax that you can use in your applications.

Have a look at the following document:

https://developers.google.com/maps/documentation/urls/guide

You can use URLs in search, directions, map and street view modes.

For example, to show the marker at specified position you can use the following URL:

https://www.google.com/maps/search/?api=1&query=36.26577,-92.54324

For further details please read aforementioned documentation.

You can also file feature requests for this API in Google issue tracker.

Hope this helps!

Docker and securing passwords

Something simply like this will work I guess if it is bash shell.

read -sp "db_password:" password | docker run -itd --name <container_name> --build-arg mysql_db_password=$db_password alpine /bin/bash

Simply read it silently and pass as argument in Docker image. You need to accept the variable as ARG in Dockerfile.

Create an ArrayList of unique values

If you want to make a list with unique values from an existing list you can use

List myUniqueList = myList.stream().distinct().collect(Collectors.toList());

What is the purpose of mvnw and mvnw.cmd files?

By far the best option nowadays would be using a maven container as a builder tool. A mvn.sh script like this would be enough:

#!/bin/bash
docker run --rm -ti \
 -v $(pwd):/opt/app \
 -w /opt/app \
 -e TERM=xterm \
 -v $HOME/.m2:/root/.m2 \
 maven mvn "$@"

I'm trying to use python in powershell

  1. download Nodejs for windows
  2. install node-vxxx.msi
  3. find "Install Additional Tools for Node.js" script
  4. open and install it
  5. reopen a new shell prompt, type "python" >> press "enter" >> it works!!

SQL Inner Join On Null Values

You have two options

INNER JOIN x
   ON x.qid = y.qid OR (x.qid IS NULL AND y.qid IS NULL)

or easier

INNER JOIN x
  ON x.qid IS NOT DISTINCT FROM y.qid

Dynamically allocating an array of objects

You need an assignment operator so that:

arrayOfAs[i] = A(3);

works as it should.

Regular expression to match a word or its prefix

I test examples in js. Simplest solution - just add word u need inside / /:

var reg = /cat/;
reg.test('some cat here');//1 test
true // result
reg.test('acatb');//2 test
true // result

Now if u need this specific word with boundaries, not inside any other signs-letters. We use b marker:

var reg = /\bcat\b/
reg.test('acatb');//1 test 
false // result
reg.test('have cat here');//2 test
true // result

We have also exec() method in js, whichone returns object-result. It helps f.g. to get info about place/index of our word.

var matchResult = /\bcat\b/.exec("good cat good");
console.log(matchResult.index); // 5

If we need get all matched words in string/sentence/text, we can use g modifier (global match):

"cat good cat good cat".match(/\bcat\b/g).length
// 3 

Now the last one - i need not 1 specific word, but some of them. We use | sign, it means choice/or.

"bad dog bad".match(/\bcat|dog\b/g).length
// 1

Are PHP Variables passed by value or by reference?

It seems a lot of people get confused by the way objects are passed to functions and what passing by reference means. Object are still passed by value, it's just the value that is passed in PHP5 is a reference handle. As proof:

<?php
class Holder {
    private $value;

    public function __construct($value) {
        $this->value = $value;
    }

    public function getValue() {
        return $this->value;
    }
}

function swap($x, $y) {
    $tmp = $x;
    $x = $y;
    $y = $tmp;
}

$a = new Holder('a');
$b = new Holder('b');
swap($a, $b);

echo $a->getValue() . ", " . $b->getValue() . "\n";

Outputs:

a, b

To pass by reference means we can modify the variables that are seen by the caller, which clearly the code above does not do. We need to change the swap function to:

<?php
function swap(&$x, &$y) {
    $tmp = $x;
    $x = $y;
    $y = $tmp;
}

$a = new Holder('a');
$b = new Holder('b');
swap($a, $b);

echo $a->getValue() . ", " . $b->getValue() . "\n";

Outputs:

b, a

in order to pass by reference.

Get all unique values in a JavaScript array (remove duplicates)

Code:

function RemoveDuplicates(array) {
    return array.filter(function (value, index, self) {
        return self.indexOf(value) === index;
    });
}

Usages:

var arr = ["a","a","b","c","d", "d"];

console.log(RemoveDuplicates(arr));

Result:

0: "a"
1: "b"
2: "c"
3: "d"

" app-release.apk" how to change this default generated apk name

Here is a much shorter way:

defaultConfig {
    ...
    applicationId "com.blahblah.example"
    versionCode 1
    versionName "1.0"
    setProperty("archivesBaseName", applicationId + "-v" + versionCode + "(" + versionName + ")")
    //or so
    archivesBaseName = "$applicationId-v$versionCode($versionName)"
}

It gives you name com.blahblah.example-v1(1.0)-debug.apk (in debug mode)

Android Studio add versionNameSuffix by build type name by default, if you want override this, do next:

buildTypes {
    debug {
        ...
        versionNameSuffix "-MyNiceDebugModeName"
    }
    release {
        ...
    }
}

Output in debug mode: com.blahblah.example-v1(1.0)-MyNiceDebugModeName.apk

How can I make my own event in C#?

You can declare an event with the following code:

public event EventHandler MyOwnEvent;

A custom delegate type instead of EventHandler can be used if needed.

You can find detailed information/tutorials on the use of events in .NET in the article Events Tutorial (MSDN).

Rotate an image in image source in html

If your rotation angles are fairly uniform, you can use CSS:

<img id="image_canv" src="/image.png" class="rotate90">

CSS:

.rotate90 {
    -webkit-transform: rotate(90deg);
    -moz-transform: rotate(90deg);
    -o-transform: rotate(90deg);
    -ms-transform: rotate(90deg);
    transform: rotate(90deg);
}

Otherwise, you can do this by setting a data attribute in your HTML, then using Javascript to add the necessary styling:

<img id="image_canv" src="/image.png" data-rotate="90">

Sample jQuery:

$('img').each(function() {
    var deg = $(this).data('rotate') || 0;
    var rotate = 'rotate(' + deg + 'deg)';
    $(this).css({ 
        '-webkit-transform': rotate,
        '-moz-transform': rotate,
        '-o-transform': rotate,
        '-ms-transform': rotate,
        'transform': rotate 
    });
});

Demo:

http://jsfiddle.net/verashn/6rRnd/5/

Finding the mode of a list

Simple code that finds the mode of the list without any imports:

nums = #your_list_goes_here
nums.sort()
counts = dict()
for i in nums:
    counts[i] = counts.get(i, 0) + 1
mode = max(counts, key=counts.get)

In case of multiple modes, it should return the minimum node.

View contents of database file in Android Studio

Even though this is pretty old question but I think it's still relevant today. With the latest version of android studio I found a way to see it [ I am not sure if it was available in the previous versions. ]

Here is how you can see the data in your database :

steps :

  1. Go to View > Tool Windows > Device File Explorer

  2. Then the folder data > data and you will see applications lists.

  3. There scroll down a little bit and see the package [ your package for application ].

  4. After finding your package, see databases folder and select file, right click it and save [ download ]

  5. As you can't see the data directly, there is a tool, DB Browser for SQLite, go website https://sqlitebrowser.org/

  6. Open Db browser and click open database and choose the database table you downloaded and it will show you the data.

POST an array from an HTML form without javascript

You can also post multiple inputs with the same name and have them save into an array by adding empty square brackets to the input name like this:

<input type="text" name="comment[]" value="comment1"/>
<input type="text" name="comment[]" value="comment2"/>
<input type="text" name="comment[]" value="comment3"/>
<input type="text" name="comment[]" value="comment4"/>

If you use php:

print_r($_POST['comment']) 

you will get this:

Array ( [0] => 'comment1' [1] => 'comment2' [2] => 'comment3' [3] => 'comment4' )

Python Anaconda - How to Safely Uninstall

Removing the Anaconda directory helps, but I don't think that's a good idea as you might need to use anaconda sometimes in near future. So, as suggested by mwaskom, anaconda installer automatically adds PATH variable which points to anaconda/bin directory in the ~/.bashrc file.

It looks like this

PATH="/home/linuxsagar/anaconda3/bin:$PATH

So, just comment out the line (add # in the beginning of the line). Then reload the ~/.bashrc file executing source ~/.bashrc

Now, verify the changes executing which python in the new terminal.

Increase Tomcat memory settings

try setting this

CATALINA_OPTS="-Djava.awt.headless=true -Dfile.encoding=UTF-8 
-server -Xms1536m -Xmx1536m
-XX:NewSize=256m -XX:MaxNewSize=256m -XX:PermSize=256m 
-XX:MaxPermSize=256m -XX:+DisableExplicitGC"

in {$tomcat-folder}\bin\setenv.sh (create it if necessary).

See http://www.mkyong.com/tomcat/tomcat-javalangoutofmemoryerror-permgen-space/ for more details.

Android Studio installation on Windows 7 fails, no JDK found

The answer to the original question is that, might be you are opening android studio from 32 bit shortcut icon of android studio, try to open from icon "studio64" located under .../bin/ where android studio setup is install.

Oracle date "Between" Query

As APC rightly pointed out, your start_date column appears to be a TIMESTAMP but it could be a TIMESTAMP WITH LOCAL TIMEZONE or TIMESTAMP WITH TIMEZONE datatype too. These could well influence any queries you were doing on the data if your database server was in a different timezone to yourself. However, let's keep this simple and assume you are in the same timezone as your server. First, to give you the confidence, check that the start_date is a TIMESTAMP data type.

Use the SQLPlus DESCRIBE command (or the equivalent in your IDE) to verify this column is a TIMESTAMP data type.

eg

DESCRIBE mytable

Should report :

Name        Null? Type
----------- ----- ------------
NAME              VARHAR2(20) 
START_DATE        TIMESTAMP

If it is reported as a Type = TIMESTAMP then you can query your date ranges with simplest TO_TIMESTAMP date conversion, one which requires no argument (or picture).

We use TO_TIMESTAMP to ensure that any index on the START_DATE column is considered by the optimizer. APC's answer also noted that a function based index could have been created on this column and that would influence the SQL predicate but we cannot comment on that in this query. If you want to know how to find out what indexes have been applied to table, post another question and we can answer that separately.

So, assuming there is an index on start_date, which is a TIMESTAMP datatype and you want the optimizer to consider it, your SQL would be :

select * from mytable where start_date between to_timestamp('15-JAN-10') AND to_timestamp('17-JAN-10')+.9999999

+.999999999 is very close to but isn't quite 1 so the conversion of 17-JAN-10 will be as close to midnight on that day as possible, therefore you query returns both rows.

The database will see the BETWEEN as from 15-JAN-10 00:00:00:0000000 to 17-JAN-10 23:59:59:99999 and will therefore include all dates from 15th,16th and 17th Jan 2010 whatever the time component of the timestamp.

Hope that helps.

Dazzer

Remote Procedure call failed with sql server 2008 R2

This error appears to happen when .mof files (Managed Object Format (MOF)) don’t get installed and registered correctly during set-up. To resolve this issue, I executed the following mofcomp command in command prompt to re-register the *.mof files:

mofcomp.exe "C:\Program Files (x86)\Microsoft SQL Server\100\Shared\sqlmgmproviderxpsp2up.mof"

This one worked for me

Get all parameters from JSP page

This should print out all Parameters that start with "Question".

<html><body>
<%@ page import = "java.util.*" %>
<b>Parameters:</b><br>
<%
  Enumeration parameterList = request.getParameterNames();
  while( parameterList.hasMoreElements() )
  {
    String sName = parameterList.nextElement().toString();
    if(sName.toLowerCase.startsWith("question")){
      String[] sMultiple = request.getParameterValues( sName );
      if( 1 >= sMultiple.length )
        // parameter has a single value. print it.
        out.println( sName + " = " + request.getParameter( sName ) + "<br>" );
      else
        for( int i=0; i<sMultiple.length; i++ )
          // if a paramater contains multiple values, print all of them
          out.println( sName + "[" + i + "] = " + sMultiple[i] + "<br>" );
    }
  }
%>
</body></html>

How to remove all null elements from a ArrayList or String Array?

List<String> colors = new ArrayList<>(
Arrays.asList("RED", null, "BLUE", null, "GREEN"));
// using removeIf() + Objects.isNull()
colors.removeIf(Objects::isNull);

How do I install Maven with Yum?

I've just learned of a handy packaging tool called fpm recently. Stumbling upon this question I thought I might give it a try. Turns out, after reading @OrwellHindenberg's answer, it's easy to package maven into an RPM with fpm.

yum install -y gcc make rpm-build ruby-devel rubygems
gem install fpm

create a project directory and layout the directory structure of the package

mkdir maven-build
cd maven-build
mkdir -p etc/profile.d opt

create a file that we'll install to /etc/profile.d/maven.sh, we'll store this under the newly created etc/profile.d directory as maven.sh, with the following contents

export M3_HOME=/opt/apache-maven-3.1.0
export M3=$M3_HOME/bin
export PATH=$M3:$PATH

download and unpack the latest maven in the opt directory

wget http://www.eng.lsu.edu/mirrors/apache/maven/maven-3/3.1.0/binaries/apache-maven-3.1.0-bin.tar.gz
tar -xzf apache-maven-3.1.0-bin.tar.gz -C opt

finally, build the RPM

fpm -n maven-3.1.0 -s dir -t rpm etc opt

Now you can install maven through rpm

$ rpm -Uvh maven-3.1.0-1.0-1.x86_64.rpm 
Preparing...                ########################################### [100%]
   1:maven-3.1.0            ########################################### [100%]

and viola

$ which mvn
/opt/apache-maven-3.1.0/bin/mvn

not quite yum but closer to home ;)

Easiest way to compare arrays in C#

If you don't want to compare the order but you do want to compare the count of each item, including handling null values, then I've written an extension method for this.

It gives for example the following results:

new int?[]{  }.IgnoreOrderComparison(new int?{ });                            // true
new int?[]{ 1 }.IgnoreOrderComparison(new int?{ });                           // false
new int?[]{ }.IgnoreOrderComparison(new int?{ 1 });                           // false
new int?[]{ 1 }.IgnoreOrderComparison(new int?{ 1 });                         // true
new int?[]{ 1, 2 }.IgnoreOrderComparison(new int?{ 2, 1 });                   // true
new int?[]{ 1, 2, null }.IgnoreOrderComparison(new int?{ 2, 1 });             // false
new int?[]{ 1, 2, null }.IgnoreOrderComparison(new int?{ null, 2, 1 });       // true
new int?[]{ 1, 2, null, null }.IgnoreOrderComparison(new int?{ null, 2, 1 }); // false
new int?[]{ 2 }.IgnoreOrderComparison(new int?{ 2, 2 });                      // false
new int?[]{ 2, 2 }.IgnoreOrderComparison(new int?{ 2, 2 });                   // true

Here is the code:

public static class ArrayComparisonExtensions
{
    public static bool IgnoreOrderComparison<TSource>(this IEnumerable<TSource> first, IEnumerable<TSource> second) =>
        IgnoreOrderComparison(first, second, EqualityComparer<TSource>.Default);

    public static bool IgnoreOrderComparison<TSource>(this IEnumerable<TSource> first, IEnumerable<TSource> second, IEqualityComparer<TSource> comparer)
    {
        var a = ToDictionary(first, out var firstNullCount);
        var b = ToDictionary(second, out var secondNullCount);

        if (a.Count != b.Count)
            return false;

        if (firstNullCount != secondNullCount)
            return false;

        foreach (var item in a)
        {
            if (b.TryGetValue(item.Key, out var count) && item.Value == count)
                continue;
            return false;
        }


        return true;

        Dictionary<TSource, int> ToDictionary(IEnumerable<TSource> items, out int nullCount)
        {
            nullCount = 0;
            var result = new Dictionary<TSource, int>(comparer);
            foreach (var item in items)
            {
                if (item is null)
                    nullCount++;
                else if (result.TryGetValue(item, out var count))
                    result[item] = count + 1;
                else
                    result[item] = 1;
            }

            return result;
        }
    }
}

It only enumerates each enumerable once, but it does create a dictionary for each enumerable and iterates those once too. I'd be interested in ways to improve this.

Including all the jars in a directory within the Java classpath

Please note that wildcard expansion is broken for Java 7 on Windows.

Check out this StackOverflow issue for more information.

The workaround is to put a semicolon right after the wildcard. java -cp "somewhere/*;"

Choosing the correct upper and lower HSV boundaries for color detection with`cv::inRange` (OpenCV)

To find the HSV value of Green, try following commands in Python terminal

green = np.uint8([[[0,255,0 ]]])
hsv_green = cv2.cvtColor(green,cv2.COLOR_BGR2HSV)
print hsv_green
[[[ 60 255 255]]]

How can I add reflection to a C++ application?

What you need to do is have the preprocessor generate reflection data about the fields. This data can be stored as nested classes.

First, to make it easier and cleaner to write it in the preprocessor we will use typed expression. A typed expression is just an expression that puts the type in parenthesis. So instead of writing int x you will write (int) x. Here are some handy macros to help with typed expressions:

#define REM(...) __VA_ARGS__
#define EAT(...)

// Retrieve the type
#define TYPEOF(x) DETAIL_TYPEOF(DETAIL_TYPEOF_PROBE x,)
#define DETAIL_TYPEOF(...) DETAIL_TYPEOF_HEAD(__VA_ARGS__)
#define DETAIL_TYPEOF_HEAD(x, ...) REM x
#define DETAIL_TYPEOF_PROBE(...) (__VA_ARGS__),
// Strip off the type
#define STRIP(x) EAT x
// Show the type without parenthesis
#define PAIR(x) REM x

Next, we define a REFLECTABLE macro to generate the data about each field(plus the field itself). This macro will be called like this:

REFLECTABLE
(
    (const char *) name,
    (int) age
)

So using Boost.PP we iterate over each argument and generate the data like this:

// A helper metafunction for adding const to a type
template<class M, class T>
struct make_const
{
    typedef T type;
};

template<class M, class T>
struct make_const<const M, T>
{
    typedef typename boost::add_const<T>::type type;
};


#define REFLECTABLE(...) \
static const int fields_n = BOOST_PP_VARIADIC_SIZE(__VA_ARGS__); \
friend struct reflector; \
template<int N, class Self> \
struct field_data {}; \
BOOST_PP_SEQ_FOR_EACH_I(REFLECT_EACH, data, BOOST_PP_VARIADIC_TO_SEQ(__VA_ARGS__))

#define REFLECT_EACH(r, data, i, x) \
PAIR(x); \
template<class Self> \
struct field_data<i, Self> \
{ \
    Self & self; \
    field_data(Self & self) : self(self) {} \
    \
    typename make_const<Self, TYPEOF(x)>::type & get() \
    { \
        return self.STRIP(x); \
    }\
    typename boost::add_const<TYPEOF(x)>::type & get() const \
    { \
        return self.STRIP(x); \
    }\
    const char * name() const \
    {\
        return BOOST_PP_STRINGIZE(STRIP(x)); \
    } \
}; \

What this does is generate a constant fields_n that is number of reflectable fields in the class. Then it specializes the field_data for each field. It also friends the reflector class, this is so it can access the fields even when they are private:

struct reflector
{
    //Get field_data at index N
    template<int N, class T>
    static typename T::template field_data<N, T> get_field_data(T& x)
    {
        return typename T::template field_data<N, T>(x);
    }

    // Get the number of fields
    template<class T>
    struct fields
    {
        static const int n = T::fields_n;
    };
};

Now to iterate over the fields we use the visitor pattern. We create an MPL range from 0 to the number of fields, and access the field data at that index. Then it passes the field data on to the user-provided visitor:

struct field_visitor
{
    template<class C, class Visitor, class I>
    void operator()(C& c, Visitor v, I)
    {
        v(reflector::get_field_data<I::value>(c));
    }
};


template<class C, class Visitor>
void visit_each(C & c, Visitor v)
{
    typedef boost::mpl::range_c<int,0,reflector::fields<C>::n> range;
    boost::mpl::for_each<range>(boost::bind<void>(field_visitor(), boost::ref(c), v, _1));
}

Now for the moment of truth we put it all together. Here is how we can define a Person class that is reflectable:

struct Person
{
    Person(const char *name, int age)
        :
        name(name),
        age(age)
    {
    }
private:
    REFLECTABLE
    (
        (const char *) name,
        (int) age
    )
};

Here is a generalized print_fields function using the reflection data to iterate over the fields:

struct print_visitor
{
    template<class FieldData>
    void operator()(FieldData f)
    {
        std::cout << f.name() << "=" << f.get() << std::endl;
    }
};

template<class T>
void print_fields(T & x)
{
    visit_each(x, print_visitor());
}

An example of using the print_fields with the reflectable Person class:

int main()
{
    Person p("Tom", 82);
    print_fields(p);
    return 0;
}

Which outputs:

name=Tom
age=82

And voila, we have just implemented reflection in C++, in under 100 lines of code.

How do I write a SQL query for a specific date range and date time using SQL Server 2008?

You can try this:

SELECT * FROM MYTABLE WHERE DATE BETWEEN '03/10/2014 06:25:00' and '03/12/2010 6:25:00'

Variable is accessed within inner class. Needs to be declared final

The error says it all, change:

ViewPager mPager = (ViewPager) findViewById(R.id.fieldspager);

to

final ViewPager mPager = (ViewPager) findViewById(R.id.fieldspager);

How to check if "Radiobutton" is checked?

Check if they're checked with the el.checked attribute.

Docs or this Question

_x000D_
_x000D_
let radio1 = document.querySelector('.radio1');
let radio2 = document.querySelector('.radio2');
let output = document.querySelector('.output');

function update() {
  if (radio1.checked) {
    output.innerHTML = "radio1";
  }
  else {
    output.innerHTML = "radio2";
  }
}

update();
_x000D_
<div class="radios">
  <input class="radio1" type="radio" name="radios" onchange="update()" checked>
  <input class="radio2" type="radio" name="radios" onchange="update()">
</div>
<div class="output"></div>
_x000D_
_x000D_
_x000D_

check for null date in CASE statement, where have I gone wrong?

Try:

select
     id,
     StartDate,
CASE WHEN StartDate IS NULL
    THEN 'Awaiting'
    ELSE 'Approved' END AS StartDateStatus
FROM myTable

You code would have been doing a When StartDate = NULL, I think.


NULL is never equal to NULL (as NULL is the absence of a value). NULL is also never not equal to NULL. The syntax noted above is ANSI SQL standard and the converse would be StartDate IS NOT NULL.

You can run the following:

SELECT CASE WHEN (NULL = NULL) THEN 1 ELSE 0 END AS EqualityCheck,
CASE WHEN (NULL <> NULL) THEN 1 ELSE 0 END AS InEqualityCheck,
CASE WHEN (NULL IS NULL) THEN 1 ELSE 0 END AS NullComparison

And this returns:

EqualityCheck = 0
InEqualityCheck = 0
NullComparison = 1

For completeness, in SQL Server you can:

SET ANSI_NULLS OFF;

Which would result in your equals comparisons working differently:

SET ANSI_NULLS OFF

SELECT CASE WHEN (NULL = NULL) THEN 1 ELSE 0 END AS EqualityCheck,
CASE WHEN (NULL <> NULL) THEN 1 ELSE 0 END AS InEqualityCheck,
CASE WHEN (NULL IS NULL) THEN 1 ELSE 0 END AS NullComparison

Which returns:

EqualityCheck = 1
InEqualityCheck = 0
NullComparison = 1

But I would highly recommend against doing this. People subsequently maintaining your code might be compelled to hunt you down and hurt you...

Also, it will no longer work in upcoming versions of SQL server:

https://msdn.microsoft.com/en-GB/library/ms188048.aspx

What does this thread join code mean?

When thread tA call tB.join() its causes not only waits for tB to die or tA be interrupted itself but create happens-before relation between last statement in tB and next statement after tB.join() in tA thread.

All actions in a thread happen-before any other thread successfully returns from a join() on that thread.

It means program

class App {
    // shared, not synchronized variable = bad practice
    static int sharedVar = 0;
    public static void main(String[] args) throws Exception {
        Thread threadB = new Thread(() -> {sharedVar = 1;});
        threadB.start();
        threadB.join();

        while (true) 
            System.out.print(sharedVar);
    }
}

Always print

>> 1111111111111111111111111 ...

But program

class App {
    // shared, not synchronized variable = bad practice
    static int sharedVar = 0;
    public static void main(String[] args) throws Exception {
        Thread threadB = new Thread(() -> {sharedVar = 1;});
        threadB.start();
        // threadB.join();  COMMENT JOIN

        while (true)
            System.out.print(sharedVar);
    }
}

Can print not only

>> 0000000000 ... 000000111111111111111111111111 ...

But

>> 00000000000000000000000000000000000000000000 ... 

Always only '0'.

Because Java Memory Model don't require 'transfering' new value of 'sharedVar' from threadB to main thread without heppens-before relation (thread start, thread join, usage of 'synchonized' keyword, usage of AtomicXXX variables, etc).

How can I find the latitude and longitude from address?

If you want to place your address in google map then easy way to use following

Intent searchAddress = new  Intent(Intent.ACTION_VIEW,Uri.parse("geo:0,0?q="+address));
startActivity(searchAddress);

OR

if you needed to get lat long from your address then use Google Place Api following

create a method that returns a JSONObject with the response of the HTTP Call like following

public static JSONObject getLocationInfo(String address) {
        StringBuilder stringBuilder = new StringBuilder();
        try {

        address = address.replaceAll(" ","%20");    

        HttpPost httppost = new HttpPost("http://maps.google.com/maps/api/geocode/json?address=" + address + "&sensor=false");
        HttpClient client = new DefaultHttpClient();
        HttpResponse response;
        stringBuilder = new StringBuilder();


            response = client.execute(httppost);
            HttpEntity entity = response.getEntity();
            InputStream stream = entity.getContent();
            int b;
            while ((b = stream.read()) != -1) {
                stringBuilder.append((char) b);
            }
        } catch (ClientProtocolException e) {
        } catch (IOException e) {
        }

        JSONObject jsonObject = new JSONObject();
        try {
            jsonObject = new JSONObject(stringBuilder.toString());
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return jsonObject;
    }

now pass that JSONObject to getLatLong() method like following

public static boolean getLatLong(JSONObject jsonObject) {

        try {

            longitute = ((JSONArray)jsonObject.get("results")).getJSONObject(0)
                .getJSONObject("geometry").getJSONObject("location")
                .getDouble("lng");

            latitude = ((JSONArray)jsonObject.get("results")).getJSONObject(0)
                .getJSONObject("geometry").getJSONObject("location")
                .getDouble("lat");

        } catch (JSONException e) {
            return false;

        }

        return true;
    }

I hope this helps to you nd others..!! Thank you..!!

Big O, how do you calculate/approximate it?

I'll do my best to explain it here on simple terms, but be warned that this topic takes my students a couple of months to finally grasp. You can find more information on the Chapter 2 of the Data Structures and Algorithms in Java book.


There is no mechanical procedure that can be used to get the BigOh.

As a "cookbook", to obtain the BigOh from a piece of code you first need to realize that you are creating a math formula to count how many steps of computations get executed given an input of some size.

The purpose is simple: to compare algorithms from a theoretical point of view, without the need to execute the code. The lesser the number of steps, the faster the algorithm.

For example, let's say you have this piece of code:

int sum(int* data, int N) {
    int result = 0;               // 1

    for (int i = 0; i < N; i++) { // 2
        result += data[i];        // 3
    }

    return result;                // 4
}

This function returns the sum of all the elements of the array, and we want to create a formula to count the computational complexity of that function:

Number_Of_Steps = f(N)

So we have f(N), a function to count the number of computational steps. The input of the function is the size of the structure to process. It means that this function is called such as:

Number_Of_Steps = f(data.length)

The parameter N takes the data.length value. Now we need the actual definition of the function f(). This is done from the source code, in which each interesting line is numbered from 1 to 4.

There are many ways to calculate the BigOh. From this point forward we are going to assume that every sentence that doesn't depend on the size of the input data takes a constant C number computational steps.

We are going to add the individual number of steps of the function, and neither the local variable declaration nor the return statement depends on the size of the data array.

That means that lines 1 and 4 takes C amount of steps each, and the function is somewhat like this:

f(N) = C + ??? + C

The next part is to define the value of the for statement. Remember that we are counting the number of computational steps, meaning that the body of the for statement gets executed N times. That's the same as adding C, N times:

f(N) = C + (C + C + ... + C) + C = C + N * C + C

There is no mechanical rule to count how many times the body of the for gets executed, you need to count it by looking at what does the code do. To simplify the calculations, we are ignoring the variable initialization, condition and increment parts of the for statement.

To get the actual BigOh we need the Asymptotic analysis of the function. This is roughly done like this:

  1. Take away all the constants C.
  2. From f() get the polynomium in its standard form.
  3. Divide the terms of the polynomium and sort them by the rate of growth.
  4. Keep the one that grows bigger when N approaches infinity.

Our f() has two terms:

f(N) = 2 * C * N ^ 0 + 1 * C * N ^ 1

Taking away all the C constants and redundant parts:

f(N) = 1 + N ^ 1

Since the last term is the one which grows bigger when f() approaches infinity (think on limits) this is the BigOh argument, and the sum() function has a BigOh of:

O(N)

There are a few tricks to solve some tricky ones: use summations whenever you can.

As an example, this code can be easily solved using summations:

for (i = 0; i < 2*n; i += 2) {  // 1
    for (j=n; j > i; j--) {     // 2
        foo();                  // 3
    }
}

The first thing you needed to be asked is the order of execution of foo(). While the usual is to be O(1), you need to ask your professors about it. O(1) means (almost, mostly) constant C, independent of the size N.

The for statement on the sentence number one is tricky. While the index ends at 2 * N, the increment is done by two. That means that the first for gets executed only N steps, and we need to divide the count by two.

f(N) = Summation(i from 1 to 2 * N / 2)( ... ) = 
     = Summation(i from 1 to N)( ... )

The sentence number two is even trickier since it depends on the value of i. Take a look: the index i takes the values: 0, 2, 4, 6, 8, ..., 2 * N, and the second for get executed: N times the first one, N - 2 the second, N - 4 the third... up to the N / 2 stage, on which the second for never gets executed.

On formula, that means:

f(N) = Summation(i from 1 to N)( Summation(j = ???)(  ) )

Again, we are counting the number of steps. And by definition, every summation should always start at one, and end at a number bigger-or-equal than one.

f(N) = Summation(i from 1 to N)( Summation(j = 1 to (N - (i - 1) * 2)( C ) )

(We are assuming that foo() is O(1) and takes C steps.)

We have a problem here: when i takes the value N / 2 + 1 upwards, the inner Summation ends at a negative number! That's impossible and wrong. We need to split the summation in two, being the pivotal point the moment i takes N / 2 + 1.

f(N) = Summation(i from 1 to N / 2)( Summation(j = 1 to (N - (i - 1) * 2)) * ( C ) ) + Summation(i from 1 to N / 2) * ( C )

Since the pivotal moment i > N / 2, the inner for won't get executed, and we are assuming a constant C execution complexity on its body.

Now the summations can be simplified using some identity rules:

  1. Summation(w from 1 to N)( C ) = N * C
  2. Summation(w from 1 to N)( A (+/-) B ) = Summation(w from 1 to N)( A ) (+/-) Summation(w from 1 to N)( B )
  3. Summation(w from 1 to N)( w * C ) = C * Summation(w from 1 to N)( w ) (C is a constant, independent of w)
  4. Summation(w from 1 to N)( w ) = (N * (N + 1)) / 2

Applying some algebra:

f(N) = Summation(i from 1 to N / 2)( (N - (i - 1) * 2) * ( C ) ) + (N / 2)( C )

f(N) = C * Summation(i from 1 to N / 2)( (N - (i - 1) * 2)) + (N / 2)( C )

f(N) = C * (Summation(i from 1 to N / 2)( N ) - Summation(i from 1 to N / 2)( (i - 1) * 2)) + (N / 2)( C )

f(N) = C * (( N ^ 2 / 2 ) - 2 * Summation(i from 1 to N / 2)( i - 1 )) + (N / 2)( C )

=> Summation(i from 1 to N / 2)( i - 1 ) = Summation(i from 1 to N / 2 - 1)( i )

f(N) = C * (( N ^ 2 / 2 ) - 2 * Summation(i from 1 to N / 2 - 1)( i )) + (N / 2)( C )

f(N) = C * (( N ^ 2 / 2 ) - 2 * ( (N / 2 - 1) * (N / 2 - 1 + 1) / 2) ) + (N / 2)( C )

=> (N / 2 - 1) * (N / 2 - 1 + 1) / 2 = 

   (N / 2 - 1) * (N / 2) / 2 = 

   ((N ^ 2 / 4) - (N / 2)) / 2 = 

   (N ^ 2 / 8) - (N / 4)

f(N) = C * (( N ^ 2 / 2 ) - 2 * ( (N ^ 2 / 8) - (N / 4) )) + (N / 2)( C )

f(N) = C * (( N ^ 2 / 2 ) - ( (N ^ 2 / 4) - (N / 2) )) + (N / 2)( C )

f(N) = C * (( N ^ 2 / 2 ) - (N ^ 2 / 4) + (N / 2)) + (N / 2)( C )

f(N) = C * ( N ^ 2 / 4 ) + C * (N / 2) + C * (N / 2)

f(N) = C * ( N ^ 2 / 4 ) + 2 * C * (N / 2)

f(N) = C * ( N ^ 2 / 4 ) + C * N

f(N) = C * 1/4 * N ^ 2 + C * N

And the BigOh is:

O(N²)

Creating a segue programmatically

You have to link your code to the UIStoryboard that you're using. Make sure you go into YourViewController in your UIStoryboard, click on the border around it, and then set its identifier field to a NSString that you call in your code.

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" 
                                                     bundle:nil];
YourViewController *yourViewController = 
 (YourViewController *)
  [storyboard instantiateViewControllerWithIdentifier:@"yourViewControllerID"];
[self.navigationController pushViewController:yourViewController animated:YES];

SQL Server: What is the difference between CROSS JOIN and FULL OUTER JOIN?

I'd like to add one important aspect to other answers, which actually explained this topic to me in the best way:

If 2 joined tables contain M and N rows, then cross join will always produce (M x N) rows, but full outer join will produce from MAX(M,N) to (M + N) rows (depending on how many rows actually match "on" predicate).

EDIT:

From logical query processing perspective, CROSS JOIN does indeed always produce M x N rows. What happens with FULL OUTER JOIN is that both left and right tables are "preserved", as if both LEFT and RIGHT join happened. So rows, not satisfying ON predicate, from both left and right tables are added to the result set.

Automatic creation date for Django model form objects?

Well, the above answer is correct, auto_now_add and auto_now would do it, but it would be better to make an abstract class and use it in any model where you require created_at and updated_at fields.

class TimeStampMixin(models.Model):
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        abstract = True

Now anywhere you want to use it you can do a simple inherit and you can use timestamp in any model you make like.

class Posts(TimeStampMixin):
    name = models.CharField(max_length=50)
    ...
    ...

In this way, you can leverage object-oriented reusability, in Django DRY(don't repeat yourself)

Passing a variable from one php include file to another: global vs. not

This is all you have to do:

In front.inc

global $name;
$name = 'james';

Missing artifact com.sun:tools:jar

I got this problem and it turns out that JBossDevStudio 9.1 on Windows is a 32-bit program. Eclipse, and thus the JBossDevStudio, does not work with the wrong type of JVM. 64-bit eclipse needs a 64-bit JVM, 32-bit eclipse needs a 32-bit JVM. Thus configuring Eclipse to run with my installed 64-bit JDK did not work.

Installing a 32 bit JDK and running Eclipse from that solved the problem.

At least for one of my projects, an other where I had tried to configure a runtime JDK in the Eclipse project properties is still broken.

CSS selector for "foo that contains bar"?

Is there any way you could programatically apply a class to the object?

<object class="hasparams">

then do

object.hasparams

What are the differences between struct and class in C++?

Another main difference is when it comes to Templates. As far as I know, you may use a class when you define a template but NOT a struct.

template<class T> // OK
template<struct T> // ERROR, struct not allowed here

Open Sublime Text from Terminal in macOS

For anyone looking for opening a file with Sublime on mac from terminal

open 'path/file.txt' -a '/Applications/Sublime Text.app'

How to Solve the XAMPP 1.7.7 - PHPMyAdmin - MySQL Error #2002 in Ubuntu

  1. Open config.default.php file under phpmyadmin/libraries/
  2. Find $cfg['Servers'][$i]['host'] = 'localhost'; Change to $cfg['Servers'][$i]['host'] = '127.0.0.1';
  3. refresh your phpmyadmin page, login

How to display an IFRAME inside a jQuery UI dialog

Although this is a old post, I have spent 3 hours to fix my issue and I think this might help someone in future.

Here is my jquery-dialog hack to show html content inside an <iframe> :

let modalProperties = {autoOpen: true, width: 900, height: 600, modal: true, title: 'Modal Title'};
let modalHtmlContent = '<div>My Content First div</div><div>My Content Second div</div>';

// create wrapper iframe
let wrapperIframe = $('<iframe src="" frameborder="0" style="width:100%; height:100%;"></iframe>');

// create jquery dialog by a 'div' with 'iframe' appended
$("<div></div>").append(wrapperIframe).dialog(modalProperties);

// insert html content to iframe 'body'
let wrapperIframeDocument = wrapperIframe[0].contentDocument;
let wrapperIframeBody = $('body', wrapperIframeDocument);
wrapperIframeBody.html(modalHtmlContent);

jsfiddle demo

How to close existing connections to a DB

Short Answer:

You get "close existing connections to destination database" option only in "Databases context >> Restore Wizard" and NOT ON context of any particular database.

Long Answer:

Right Click on the Databases under your Server-Name as shown below:

and select the option: "Restore Database..." from it.

db

In the "Restore Database" wizard,

  1. select one of your databases to restore
  2. in the left vertical menu, click on "Options"

db1

Here you can find the checkbox saying, "close existing connections to destination database"

db3

Just check it, and you can proceed for the restore operation.

It automatically will resume all connections after completion of the Restore.

How to fire AJAX request Periodically?

As others have pointed out setInterval and setTimeout will do the trick. I wanted to highlight a bit more advanced technique that I learned from this excellent video by Paul Irish: http://paulirish.com/2010/10-things-i-learned-from-the-jquery-source/

For periodic tasks that might end up taking longer than the repeat interval (like an HTTP request on a slow connection) it's best not to use setInterval(). If the first request hasn't completed and you start another one, you could end up in a situation where you have multiple requests that consume shared resources and starve each other. You can avoid this problem by waiting to schedule the next request until the last one has completed:

// Use a named immediately-invoked function expression.
(function worker() {
  $.get('ajax/test.html', function(data) {
    // Now that we've completed the request schedule the next one.
    $('.result').html(data);
    setTimeout(worker, 5000);
  });
})();

For simplicity I used the success callback for scheduling. The down side of this is one failed request will stop updates. To avoid this you could use the complete callback instead:

(function worker() {
  $.ajax({
    url: 'ajax/test.html', 
    success: function(data) {
      $('.result').html(data);
    },
    complete: function() {
      // Schedule the next request when the current one's complete
      setTimeout(worker, 5000);
    }
  });
})();

How to get input text value on click in ReactJS

First of all, you can't pass to alert second argument, use concatenation instead

alert("Input is " + inputValue);

Example

However in order to get values from input better to use states like this

_x000D_
_x000D_
var MyComponent = React.createClass({_x000D_
  getInitialState: function () {_x000D_
    return { input: '' };_x000D_
  },_x000D_
_x000D_
  handleChange: function(e) {_x000D_
    this.setState({ input: e.target.value });_x000D_
  },_x000D_
_x000D_
  handleClick: function() {_x000D_
    console.log(this.state.input);_x000D_
  },_x000D_
_x000D_
  render: function() {_x000D_
    return (_x000D_
      <div>_x000D_
        <input type="text" onChange={ this.handleChange } />_x000D_
        <input_x000D_
          type="button"_x000D_
          value="Alert the text input"_x000D_
          onClick={this.handleClick}_x000D_
        />_x000D_
      </div>_x000D_
    );_x000D_
  }_x000D_
});_x000D_
_x000D_
ReactDOM.render(_x000D_
  <MyComponent />,_x000D_
  document.getElementById('container')_x000D_
);
_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>_x000D_
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>_x000D_
<div id="container"></div>
_x000D_
_x000D_
_x000D_

Border in shape xml

If you want make a border in a shape xml. You need to use:

For the external border,you need to use:

<stroke/>

For the internal background,you need to use:

<solid/>

If you want to set corners,you need to use:

<corners/>

If you want a padding betwen border and the internal elements,you need to use:

<padding/>

Here is a shape xml example using the above items. It works for me

<shape xmlns:android="http://schemas.android.com/apk/res/android"> 
  <stroke android:width="2dp" android:color="#D0CFCC" /> 
  <solid android:color="#F8F7F5" /> 
  <corners android:radius="10dp" />
  <padding android:left="2dp" android:top="2dp" android:right="2dp" android:bottom="2dp" />
</shape>

Set icon for Android application

Goto File->new->ImageAsset.

From their you can create Image Assets for your icon.

After that we will get icon image in mipmap different formats like hdpi,mdpi,xhdpi,xxhdpi,xxxhdpi.

Now goto AndroidManifest.xml

<application android:icon="@mipmap/your_Icon"> ....</application>

How to split one string into multiple variables in bash shell?

If you know it's going to be just two fields, you can skip the extra subprocesses like this:

var1=${STR%-*}
var2=${STR#*-}

What does this do? ${STR%-*} deletes the shortest substring of $STR that matches the pattern -* starting from the end of the string. ${STR#*-} does the same, but with the *- pattern and starting from the beginning of the string. They each have counterparts %% and ## which find the longest anchored pattern match. If anyone has a helpful mnemonic to remember which does which, let me know! I always have to try both to remember.

Date Difference in php on days?

strtotime will convert your date string to a unix time stamp. (seconds since the unix epoch.

$ts1 = strtotime($date1);
$ts2 = strtotime($date2);

$seconds_diff = $ts2 - $ts1;

Cell Style Alignment on a range

Don't use "Style:

worksheet.Cells[y,x].HorizontalAlignment = Microsoft.Office.Interop.Excel.XlHAlign.xlHAlignLeft;

How to properly set the 100% DIV height to match document/window height?

why don't you use width: 100% and height: 100%.

.substring error: "is not a function"

try this code below :

var currentLocation = document.location;
muzLoc = String(currentLocation).substring(0,45);
prodLoc = String(currentLocation).substring(0,48); 
techLoc = String(currentLocation).substring(0,47);

When does Git refresh the list of remote branches?

The OP did not ask for cleanup for all remotes, rather for all branches of default remote.

So git fetch --prune is what should be used.

Setting git config remote.origin.prune true makes --prune automatic. In that case just git fetch will also prune stale remote branches from the local copy. See also Automatic prune with Git fetch or pull.

Note that this does not clean local branches that are no longer tracking a remote branch. See How to prune local tracking branches that do not exist on remote anymore for that.

How do I concatenate strings in Swift?

You could use SwiftString (https://github.com/amayne/SwiftString) to do this.

"".join(["string1", "string2", "string3"]) // "string1string2string"
" ".join(["hello", "world"]) // "hello world"

DISCLAIMER: I wrote this extension

How to display .svg image using swift

In case you want to use a WKWebView to load a .svg image that is coming from a URLRequest, you can simply achieve it like this:

Swift 4

if let request = URLRequest(url: urlString), let svgString = try? String(contentsOf: request) {
  wkWebView.loadHTMLString(svgString, baseURL: request)
}

It's much simpler than the other ways of doing it, and you can also persist your .svg string somewhere to load it later, even offline if you need to.

Unknown column in 'field list' error on MySQL Update query

Enclose any string to be passed to the mysql server inside single quotes; e.g.:

$name = "my name"
$query = " INSERT INTO mytable VALUES ( 1 , '$name') "

Note that although the query is enclosed between double quotes, you must enclose any string in single quotes.

How do I create an .exe for a Java program?

Most of the programs that convert java applications to .exe files are just wrappers around the program, and the end user will still need the JRE installed to run it. As far as I know there aren't any converters that will make it a native executable from bytecode (There have been attempts, but if any turned out successful you would hear of them by now).

As for wrappers, the best ones i've used (as previously suggested) are:

JSmooth

and

Launch4j

best of luck!

How do I hide the bullets on my list for the sidebar?

You have a selector ul on line 252 which is setting list-style: square outside none (a square bullet). You'll have to change it to list-style: none or just remove the line.

If you only want to remove the bullets from that specific instance, you can use the specific selector for that list and its items as follows:

ul#groups-list.items-list { list-style: none }

Python string.join(list) on object array rather than string array

The built-in string constructor will automatically call obj.__str__:

''.join(map(str,list))

How to properly upgrade node using nvm

if you have 4.2 and want to install 5.0.0 then

nvm install v5.0.0 --reinstall-packages-from=4.2

the answer of gabrielperales is right except that he missed the "=" sign at the end. if you don't put the "=" sign then new node version will be installed but the packages won't be installed.

source: sitepoint

How to include an HTML page into another HTML page without frame/iframe?

You could use HTML5 for this:

<link rel="import" href="/path/to/file.html">

Update – July 2020: This feature is no longer supported by most major browsers, and generally considered obsolete. See caniuse for the list of browsers which do still support it.

java.io.StreamCorruptedException: invalid stream header: 7371007E

If you are sending multiple objects, it's often simplest to put them some kind of holder/collection like an Object[] or List. It saves you having to explicitly check for end of stream and takes care of transmitting explicitly how many objects are in the stream.

EDIT: Now that I formatted the code, I see you already have the messages in an array. Simply write the array to the object stream, and read the array on the server side.

Your "server read method" is only reading one object. If it is called multiple times, you will get an error since it is trying to open several object streams from the same input stream. This will not work, since all objects were written to the same object stream on the client side, so you have to mirror this arrangement on the server side. That is, use one object input stream and read multiple objects from that.

(The error you get is because the objectOutputStream writes a header, which is expected by objectIutputStream. As you are not writing multiple streams, but simply multiple objects, then the next objectInputStream created on the socket input fails to find a second header, and throws an exception.)

To fix it, create the objectInputStream when you accept the socket connection. Pass this objectInputStream to your server read method and read Object from that.

Only numbers. Input number in React

Maybe, it will be helpful for someone
Recently I used this solution for my App
I am not sure that is a correct solution but it works fine.

this.state = {
    inputValue: "",
    isInputNotValid: false
}

handleInputValue = (evt) => {
    this.validationField(evt, "isInputNotValid", "inputValue");
}

validationField = (evt, isFieldNotValid, fieldValue ) => {
   if (evt.target.value && !isNaN(evt.target.value)) {
        this.setState({ 
            [isFieldNotValid]: false,
            [fieldValue]: evt.target.value,
        });
    } else {
        this.setState({ 
            [isFieldNotValid]: true,
            [fieldValue]: "",
        });
    }
}

<input className={this.state.isInputNotValid ? "error" : null} type="text" onChange="this.handleInputValue" />

The main idea, that state won't update till the condition isn't true and value will be empty.
Don't need to use onKeyPress, Down etc.,
also if you use these methods they aren't working on touch devices

Laravel: getting a a single value from a MySQL query

Edit:

Sorry i forgot about pluck() as many have commented : Easiest way is :

return DB::table('users')->where('username', $username)->pluck('groupName');

Which will directly return the only the first result for the requested row as a string.

Using the fluent query builder you will obtain an array anyway. I mean The Query Builder has no idea how many rows will come back from that query. Here is what you can do to do it a bit cleaner

$result = DB::table('users')->select('groupName')->where('username', $username)->first();

The first() tells the queryBuilder to return only one row so no array, so you can do :

return $result->groupName;

Hope it helps

How to sort a List<Object> alphabetically using Object name field

Here is a version of Robert B's answer that works for List<T> and sorting by a specified String property of the object using Reflection and no 3rd party libraries

/**
 * Sorts a List by the specified String property name of the object.
 * 
 * @param list
 * @param propertyName
 */
public static <T> void sortList(List<T> list, final String propertyName) {

    if (list.size() > 0) {
        Collections.sort(list, new Comparator<T>() {
            @Override
            public int compare(final T object1, final T object2) {
                String property1 = (String)ReflectionUtils.getSpecifiedFieldValue (propertyName, object1);
                String property2 = (String)ReflectionUtils.getSpecifiedFieldValue (propertyName, object2);
                return property1.compareToIgnoreCase (property2);
            }
        });
    }
}


public static Object getSpecifiedFieldValue (String property, Object obj) {

    Object result = null;

    try {
        Class<?> objectClass = obj.getClass();
        Field objectField = getDeclaredField(property, objectClass);
        if (objectField!=null) {
            objectField.setAccessible(true);
            result = objectField.get(obj);
        }
    } catch (Exception e) {         
    }
    return result;
}

public static Field getDeclaredField(String fieldName, Class<?> type) {

    Field result = null;
    try {
        result = type.getDeclaredField(fieldName);
    } catch (Exception e) {
    }       

    if (result == null) {
        Class<?> superclass = type.getSuperclass();     
        if (superclass != null && !superclass.getName().equals("java.lang.Object")) {       
            return getDeclaredField(fieldName, type.getSuperclass());
        }
    }
    return result;
}

Reporting Services Remove Time from DateTime in Expression

If you have to display the field on report header then try this... RightClick on Textbox > Properties > Category > date > select *Format (Note this will maintain the regional settings).

Since this question has been viewed many times, I'm posting it... Hope it helps.

enter image description here

Soft keyboard open and close listener in an activity in Android

A different approach would be to check when the user stopped typing...

When a TextEdit is in focus (user is/was typing) you could hide the views (focus listener)

and use a Handler + Runnable and a text change listener to close the keyboard (regardless of its visibility) and show the views after some delay.

The main thing to look out for would be the delay you use, which would depend on the content of these TextEdits.

Handler timeoutHandler = new Handler();
Runnable typingRunnable = new Runnable() {
    public void run() {
        // current TextEdit
        View view = getCurrentFocus();

        InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
        // reset focus
        view.clearFocus();
        // close keyboard (whether its open or not)
        imm.hideSoftInputFromWindow(view.getWindowToken(), InputMethodManager.RESULT_UNCHANGED_SHOWN);

        // SET VIEWS VISIBLE
    }
};

editText.setOnFocusChangeListener(new View.OnFocusChangeListener() {
    @Override
    public void onFocusChange(View v, boolean hasFocus) {
        if (hasFocus) {
            // SET VIEWS GONE

            // reset handler
            timeoutHandler.removeCallbacks(typingRunnable);
            timeoutHandler.postDelayed(typingRunnable, TYPING_TIMEOUT);
        }
    }
});

editText.addTextChangedListener(new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
        // Reset Handler...
        timeoutHandler.removeCallbacks(typingRunnable);
    }

    @Override
    public void afterTextChanged(Editable s) {
        // Reset Handler Cont.
        if (editText.getText().toString().trim().length() > 0) {
            timeoutHandler.postDelayed(typingRunnable, TYPING_TIMEOUT);
        }
    }
});

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

you make the use of the HTML Helper and have

    @using(Html.BeginForm())
    {
        Username: <input type="text" name="username" /> <br />
        Password: <input type="text" name="password" /> <br />
        <input type="submit" value="Login">
        <input type="submit" value="Create Account"/>
    }

or use the Url helper

<form method="post" action="@Url.Action("MyAction", "MyController")" >

Html.BeginForm has several (13) overrides where you can specify more information, for example, a normal use when uploading files is using:

@using(Html.BeginForm("myaction", "mycontroller", FormMethod.Post, new {enctype = "multipart/form-data"}))
{
    < ... >
}

If you don't specify any arguments, the Html.BeginForm() will create a POST form that points to your current controller and current action. As an example, let's say you have a controller called Posts and an action called Delete

public ActionResult Delete(int id)
{
   var model = db.GetPostById(id);
   return View(model);
}

[HttpPost]
public ActionResult Delete(int id)
{
    var model = db.GetPostById(id);
    if(model != null) 
        db.DeletePost(id);

    return RedirectToView("Index");
}

and your html page would be something like:

<h2>Are you sure you want to delete?</h2>
<p>The Post named <strong>@Model.Title</strong> will be deleted.</p>

@using(Html.BeginForm())
{
    <input type="submit" class="btn btn-danger" value="Delete Post"/>
    <text>or</text>
    @Url.ActionLink("go to list", "Index")
}

Jquery UI tooltip does not support html content

To avoid placing HTML tags in the title attribute, another solution is to use markdown. For instance, you could use [br] to represent a line break, then perform a simple replace in the content function.

In title attribute:

"Sample Line 1[br][br]Sample Line 2"

In your content function:

content: function () {
    return $(this).attr('title').replace(/\[br\]/g,"<br />");
}

I keep getting "Uncaught SyntaxError: Unexpected token o"

Looks like jQuery takes a guess about the datatype. It does the JSON parsing even though you're not calling getJSON()-- then when you try to call JSON.parse() on an object, you're getting the error.

Further explanation can be found in Aditya Mittal's answer.

OS X Sprite Kit Game Optimal Default Window Size

You should target the smallest, not the largest, supported pixel resolution by the devices your app can run on.

Say if there's an actual Mac computer that can run OS X 10.9 and has a native screen resolution of only 1280x720 then that's the resolution you should focus on. Any higher and your game won't correctly run on this device and you could as well remove that device from your supported devices list.

You can rely on upscaling to match larger screen sizes, but you can't rely on downscaling to preserve possibly important image details such as text or smaller game objects.

The next most important step is to pick a fitting aspect ratio, be it 4:3 or 16:9 or 16:10, that ideally is the native aspect ratio on most of the supported devices. Make sure your game only scales to fit on devices with a different aspect ratio.

You could scale to fill but then you must ensure that on all devices the cropped areas will not negatively impact gameplay or the use of the app in general (ie text or buttons outside the visible screen area). This will be harder to test as you'd actually have to have one of those devices or create a custom build that crops the view accordingly.

Alternatively you can design multiple versions of your game for specific and very common screen resolutions to provide the best game experience from 13" through 27" displays. Optimized designs for iMac (desktop) and a Macbook (notebook) devices make the most sense, it'll be harder to justify making optimized versions for 13" and 15" plus 21" and 27" screens.

But of course this depends a lot on the game. For example a tile-based world game could simply provide a larger viewing area onto the world on larger screen resolutions rather than scaling the view up. Provided that this does not alter gameplay, like giving the player an unfair advantage (specifically in multiplayer).

You should provide @2x images for the Retina Macbook Pro and future Retina Macs.

What should every programmer know about security?

Also be sure to check out the OWASP Top 10 List for a categorization of all the main attack vectors/vulnerabilities.

These things are fascinating to read about. Learning to think like an attacker will train you of what to think about as you're writing your own code.

jQuery .each() index?

From the jQuery.each() documentation:

.each( function(index, Element) )
    function(index, Element)A function to execute for each matched element.

So you'll want to use:

$('#list option').each(function(i,e){
    //do stuff
});

...where index will be the index and element will be the option element in list

Meaning of = delete after function declaration

A deleted function is implicitly inline

(Addendum to existing answers)

... And a deleted function shall be the first declaration of the function (except for deleting explicit specializations of function templates - deletion should be at the first declaration of the specialization), meaning you cannot declare a function and later delete it, say, at its definition local to a translation unit.

Citing [dcl.fct.def.delete]/4:

A deleted function is implicitly inline. ( Note: The one-definition rule ([basic.def.odr]) applies to deleted definitions. — end note ] A deleted definition of a function shall be the first declaration of the function or, for an explicit specialization of a function template, the first declaration of that specialization. [ Example:

struct sometype {
  sometype();
};
sometype::sometype() = delete;      // ill-formed; not first declaration

end example )

A primary function template with a deleted definition can be specialized

Albeit a general rule of thumb is to avoid specializing function templates as specializations do not participate in the first step of overload resolution, there are arguable some contexts where it can be useful. E.g. when using a non-overloaded primary function template with no definition to match all types which one would not like implicitly converted to an otherwise matching-by-conversion overload; i.e., to implicitly remove a number of implicit-conversion matches by only implementing exact type matches in the explicit specialization of the non-defined, non-overloaded primary function template.

Before the deleted function concept of C++11, one could do this by simply omitting the definition of the primary function template, but this gave obscure undefined reference errors that arguably gave no semantic intent whatsoever from the author of primary function template (intentionally omitted?). If we instead explicitly delete the primary function template, the error messages in case no suitable explicit specialization is found becomes much nicer, and also shows that the omission/deletion of the primary function template's definition was intentional.

#include <iostream>
#include <string>

template< typename T >
void use_only_explicit_specializations(T t);

template<>
void use_only_explicit_specializations<int>(int t) {
    std::cout << "int: " << t;
}

int main()
{
    const int num = 42;
    const std::string str = "foo";
    use_only_explicit_specializations(num);  // int: 42
    //use_only_explicit_specializations(str); // undefined reference to `void use_only_explicit_specializations< ...
}

However, instead of simply omitting a definition for the primary function template above, yielding an obscure undefined reference error when no explicit specialization matches, the primary template definition can be deleted:

#include <iostream>
#include <string>

template< typename T >
void use_only_explicit_specializations(T t) = delete;

template<>
void use_only_explicit_specializations<int>(int t) {
    std::cout << "int: " << t;
}

int main()
{
    const int num = 42;
    const std::string str = "foo";
    use_only_explicit_specializations(num);  // int: 42
    use_only_explicit_specializations(str);
    /* error: call to deleted function 'use_only_explicit_specializations' 
       note: candidate function [with T = std::__1::basic_string<char>] has 
       been explicitly deleted
       void use_only_explicit_specializations(T t) = delete; */
}

Yielding a more more readable error message, where the deletion intent is also clearly visible (where an undefined reference error could lead to the developer thinking this an unthoughtful mistake).

Returning to why would we ever want to use this technique? Again, explicit specializations could be useful to implicitly remove implicit conversions.

#include <cstdint>
#include <iostream>

void warning_at_best(int8_t num) { 
    std::cout << "I better use -Werror and -pedantic... " << +num << "\n";
}

template< typename T >
void only_for_signed(T t) = delete;

template<>
void only_for_signed<int8_t>(int8_t t) {
    std::cout << "UB safe! 1 byte, " << +t << "\n";
}

template<>
void only_for_signed<int16_t>(int16_t t) {
    std::cout << "UB safe! 2 bytes, " << +t << "\n";
}

int main()
{
    const int8_t a = 42;
    const uint8_t b = 255U;
    const int16_t c = 255;
    const float d = 200.F;

    warning_at_best(a); // 42
    warning_at_best(b); // implementation-defined behaviour, no diagnostic required
    warning_at_best(c); // narrowing, -Wconstant-conversion warning
    warning_at_best(d); // undefined behaviour!

    only_for_signed(a);
    only_for_signed(c);

    //only_for_signed(b);  
    /* error: call to deleted function 'only_for_signed' 
       note: candidate function [with T = unsigned char] 
             has been explicitly deleted
       void only_for_signed(T t) = delete; */

    //only_for_signed(d);
    /* error: call to deleted function 'only_for_signed' 
       note: candidate function [with T = float] 
             has been explicitly deleted
       void only_for_signed(T t) = delete; */
}

How to send a JSON object using html form data

Get complete form data as array and json stringify it.

var formData = JSON.stringify($("#myForm").serializeArray());

You can use it later in ajax. Or if you are not using ajax; put it in hidden textarea and pass to server. If this data is passed as json string via normal form data then you have to decode it using json_decode. You'll then get all data in an array.

$.ajax({
  type: "POST",
  url: "serverUrl",
  data: formData,
  success: function(){},
  dataType: "json",
  contentType : "application/json"
});

How to get the browser viewport dimensions?

This is the way I do it, I tried it in IE 8 -> 10, FF 35, Chrome 40, it will work very smooth in all modern browsers (as window.innerWidth is defined) and in IE 8 (with no window.innerWidth) it works smooth as well, any issue (like flashing because of overflow: "hidden"), please report it. I'm not really interested on the viewport height as I made this function just to workaround some responsive tools, but it might be implemented. Hope it helps, I appreciate comments and suggestions.

function viewportWidth () {
  if (window.innerWidth) return window.innerWidth;
  var
  doc = document,
  html = doc && doc.documentElement,
  body = doc && (doc.body || doc.getElementsByTagName("body")[0]),
  getWidth = function (elm) {
    if (!elm) return 0;
    var setOverflow = function (style, value) {
      var oldValue = style.overflow;
      style.overflow = value;
      return oldValue || "";
    }, style = elm.style, oldValue = setOverflow(style, "hidden"), width = elm.clientWidth || 0;
    setOverflow(style, oldValue);
    return width;
  };
  return Math.max(
    getWidth(html),
    getWidth(body)
  );
}

Provide static IP to docker containers via docker-compose

I was facing some difficulties with an environment variable that is with custom name (not with container name /port convention for KAPACITOR_BASE_URL and KAPACITOR_ALERTS_ENDPOINT). If we give service name in this case it wouldn't resolve the ip as

KAPACITOR_BASE_URL:  http://kapacitor:9092

In above http://[**kapacitor**]:9092 would not resolve to http://172.20.0.2:9092

I resolved the static IPs issues using subnetting configurations.

version: "3.3"

networks:
  frontend:
    ipam:
      config:
        - subnet: 172.20.0.0/24
services:
    db:
        image: postgres:9.4.4
        networks:
            frontend:
                ipv4_address: 172.20.0.5
        ports:
            - "5432:5432"
        volumes:
            - postgres_data:/var/lib/postgresql/data

    redis:
        image: redis:latest
        networks:
            frontend:
                ipv4_address: 172.20.0.6
        ports:
            - "6379"

    influxdb:
        image: influxdb:latest
        ports:
            - "8086:8086"
            - "8083:8083"
        volumes:
            - ../influxdb/influxdb.conf:/etc/influxdb/influxdb.conf
            - ../influxdb/inxdb:/var/lib/influxdb
        networks:
            frontend:
                ipv4_address: 172.20.0.4
        environment:
          INFLUXDB_HTTP_AUTH_ENABLED: "false"
          INFLUXDB_ADMIN_ENABLED: "true"
          INFLUXDB_USERNAME: "db_username"
          INFLUXDB_PASSWORD: "12345678"
          INFLUXDB_DB: db_customers

    kapacitor:
        image: kapacitor:latest
        ports: 
            - "9092:9092"
        networks:
            frontend:
                ipv4_address: 172.20.0.2
        depends_on:
            - influxdb
        volumes:
            - ../kapacitor/kapacitor.conf:/etc/kapacitor/kapacitor.conf
            - ../kapacitor/kapdb:/var/lib/kapacitor
        environment:
          KAPACITOR_INFLUXDB_0_URLS_0: http://influxdb:8086

    web:
        build: .
        environment:
          RAILS_ENV: $RAILS_ENV
        command: bundle exec rails s -b 0.0.0.0
        ports:
            - "3000:3000"
        networks:
            frontend:
                ipv4_address: 172.20.0.3
        links:
            - db
            - kapacitor
        depends_on:
            - db
        volumes:
            - .:/var/app/current
        environment:
          DATABASE_URL: postgres://postgres@db
          DATABASE_USERNAME: postgres
          DATABASE_PASSWORD: postgres
          INFLUX_URL: http://influxdb:8086
          INFLUX_USER: db_username
          INFLUX_PWD: 12345678
          KAPACITOR_BASE_URL:  http://172.20.0.2:9092
          KAPACITOR_ALERTS_ENDPOINT: http://172.20.0.3:3000

volumes:
  postgres_data:

sqlplus error on select from external table: ORA-29913: error in executing ODCIEXTTABLEOPEN callout

When you want to create an external_table, all field's name must be written in UPPERCASE.

Done.

Android LinearLayout : Add border with shadow around a LinearLayout

Use this single line and hopefully you will achieve the best result;

use: android:elevation="3dp" Adjust the size as much as you need and this is the best and simplest way to achieve the shadow like buttons and other default android shadows. Let me know if it worked!

What is the use of printStackTrace() method in Java?

printStackTrace() helps the programmer to understand where the actual problem occurred. It helps to trace the exception. it is printStackTrace() method of Throwable class inherited by every exception class. This method prints the same message of e object and also the line number where the exception occurred.

The following is an another example of print stack of the Exception in Java.

public class Demo {
   public static void main(String[] args) {
      try {
         ExceptionFunc();
      } catch(Throwable e) {
         e.printStackTrace();
      }
   }
   public static void ExceptionFunc() throws Throwable {
      Throwable t = new Throwable("This is new Exception in Java...");

      StackTraceElement[] trace = new StackTraceElement[] {
         new StackTraceElement("ClassName","methodName","fileName",5)
      };
      t.setStackTrace(trace);
      throw t;
   }
}

java.lang.Throwable: This is new Exception in Java... at ClassName.methodName(fileName:5)

Convert double to BigDecimal and set BigDecimal Precision

Why not :

b = b.setScale(2, RoundingMode.HALF_UP);

Correct way to pause a Python program

I have had a similar question and I was using signal:

import signal

def signal_handler(signal_number, frame):
    print "Proceed ..."

signal.signal(signal.SIGINT, signal_handler)
signal.pause()

So you register a handler for the signal SIGINT and pause waiting for any signal. Now from outside your program (e.g. in bash), you can run kill -2 <python_pid>, which will send signal 2 (i.e. SIGINT) to your python program. Your program will call your registered handler and proceed running.

Convert php array to Javascript

This is my function. JavaScript must be under PHP otherwise use SESSION.

<?php
 $phpArray=array(1,2,3,4,5,6);
?>

<div id="arrayCon" style="width:300px;"></div>

<script type="text/javascript">
var jsArray = new Array();
<?php
 $numArray=count($phpArray);
 for($i=0;$i<$numArray;$i++){
  echo "jsArray[$i] = ". $phpArray[$i] . ";\n";
 }
?>
$("#arrayCon").text(jsArray[1]);
</script>

Last row can be ....text(jsArray); and will be shown "1,2,3,4,5,6"

What is the difference between UNION and UNION ALL?

UNION - results in distinct records

while

UNION ALL - results in all the records including duplicates.

Both are blocking operators and hence I personally prefer using JOINS over Blocking Operators(UNION, INTERSECT, UNION ALL etc. ) anytime.

To illustrate why Union operation performs poorly in comparison to Union All checkout the following example.

CREATE TABLE #T1 (data VARCHAR(10))

INSERT INTO #T1
SELECT 'abc'
UNION ALL
SELECT 'bcd'
UNION ALL
SELECT 'cde'
UNION ALL
SELECT 'def'
UNION ALL
SELECT 'efg'


CREATE TABLE #T2 (data VARCHAR(10))

INSERT INTO #T2
SELECT 'abc'
UNION ALL
SELECT 'cde'
UNION ALL
SELECT 'efg'

enter image description here

Following are results of UNION ALL and UNION operations.

enter image description here

A UNION statement effectively does a SELECT DISTINCT on the results set. If you know that all the records returned are unique from your union, use UNION ALL instead, it gives faster results.

Using UNION results in Distinct Sort operations in the Execution Plan. Proof to prove this statement is shown below:

enter image description here

How can I give the Intellij compiler more heap space?

There is a

idea64.exe

starter in

IntelliJ IDEA 13.1.5\bin

so you can address more space.

How do I find the difference between two values without knowing which is larger?

abs function is definitely not what you need as it is not calculating the distance. Try abs (-25+15) to see that it's not working. A distance between the numbers is 40 but the output will be 10. Because it's doing the math and then removing "minus" in front. I am using this custom function:


def distance(a, b):
    if (a < 0) and (b < 0) or (a > 0) and (b > 0):
        return abs( abs(a) - abs(b) )
    if (a < 0) and (b > 0) or (a > 0) and (b < 0):
        return abs( abs(a) + abs(b) )

print distance(-25, -15) print distance(25, -15) print distance(-25, 15) print distance(25, 15)

Display XML content in HTML page

2017 Update I guess. textarea worked fine for me using Spring, Bootstrap and a bunch of other things. Got the SOAP payload stored in a DB, read by Spring and push via Spring-MVC. xmp didn't work at all.

What is `git push origin master`? Help with git's refs, heads and remotes

Or as a single command:

git push -u origin master:my_test

Pushes the commits from your local master branch to a (possibly new) remote branch my_test and sets up master to track origin/my_test.

How to play .wav files with java

A class that will play a WAV file, blocking until the sound has finished playing:

class Sound implements Playable {

    private final Path wavPath;
    private final CyclicBarrier barrier = new CyclicBarrier(2);

    Sound(final Path wavPath) {

        this.wavPath = wavPath;
    }

    @Override
    public void play() throws LineUnavailableException, IOException, UnsupportedAudioFileException {

        try (final AudioInputStream audioIn = AudioSystem.getAudioInputStream(wavPath.toFile());
             final Clip clip = AudioSystem.getClip()) {

            listenForEndOf(clip);
            clip.open(audioIn);
            clip.start();
            waitForSoundEnd();
        }
    }

    private void listenForEndOf(final Clip clip) {

        clip.addLineListener(event -> {
            if (event.getType() == LineEvent.Type.STOP) waitOnBarrier();
        });
    }

    private void waitOnBarrier() {

        try {

            barrier.await();
        } catch (final InterruptedException ignored) {
        } catch (final BrokenBarrierException e) {

            throw new RuntimeException(e);
        }
    }

    private void waitForSoundEnd() {

        waitOnBarrier();
    }
}

The transaction log for database is full. To find out why space in the log cannot be reused, see the log_reuse_wait_desc column in sys.databases

As an aside, it is always a good practice (and possibly a solution for this type of issue) to delete a large number of rows by using batches:

WHILE EXISTS (SELECT 1 
              FROM   YourTable 
              WHERE  <yourCondition>) 
  DELETE TOP(10000) FROM YourTable 
  WHERE  <yourCondition>

How to convert string representation of list to a list?

Assuming that all your inputs are lists and that the double quotes in the input actually don't matter, this can be done with a simple regexp replace. It is a bit perl-y but works like a charm. Note also that the output is now a list of unicode strings, you didn't specify that you needed that, but it seems to make sense given unicode input.

import re
x = u'[ "A","B","C" , " D"]'
junkers = re.compile('[[" \]]')
result = junkers.sub('', x).split(',')
print result
--->  [u'A', u'B', u'C', u'D']

The junkers variable contains a compiled regexp (for speed) of all characters we don't want, using ] as a character required some backslash trickery. The re.sub replaces all these characters with nothing, and we split the resulting string at the commas.

Note that this also removes spaces from inside entries u'["oh no"]' ---> [u'ohno']. If this is not what you wanted, the regexp needs to be souped up a bit.

Passing a variable from node.js to html

I found the possible way to write.

Server Side -

app.get('/main', function(req, res) {

  var name = 'hello';

  res.render(__dirname + "/views/layouts/main.html", {name:name});

});

Client side (main.html) -

<h1><%= name %></h1>

How to convert PDF files to images

The NuGet package Pdf2Png is available for free and is only protected by the MIT License, which is very open.

I've tested around a bit and this is the code to get it to convert a PDF file to an image (tt does save the image in the debug folder).

using cs_pdf_to_image;
using PdfToImage;

private void BtnConvert_Click(object sender, EventArgs e)
{
    if(openFileDialog1.ShowDialog() == DialogResult.OK)
    {
        try
        {
            string PdfFile = openFileDialog1.FileName;
            string PngFile = "Convert.png";
            List<string> Conversion = cs_pdf_to_image.Pdf2Image.Convert(PdfFile, PngFile);
            Bitmap Output = new Bitmap(PngFile);
            PbConversion.Image = Output;
        }
        catch(Exception E)
        {
            MessageBox.Show(E.Message);
        }
    }
}

javax.crypto.IllegalBlockSizeException : Input length must be multiple of 16 when decrypting with padded cipher

The algorithm you are using, "AES", is a shorthand for "AES/ECB/NoPadding". What this means is that you are using the AES algorithm with 128-bit key size and block size, with the ECB mode of operation and no padding.

In other words: you are only able to encrypt data in blocks of 128 bits or 16 bytes. That's why you are getting that IllegalBlockSizeException exception.

If you want to encrypt data in sizes that are not multiple of 16 bytes, you are either going to have to use some kind of padding, or a cipher-stream. For instance, you could use CBC mode (a mode of operation that effectively transforms a block cipher into a stream cipher) by specifying "AES/CBC/NoPadding" as the algorithm, or PKCS5 padding by specifying "AES/ECB/PKCS5", which will automatically add some bytes at the end of your data in a very specific format to make the size of the ciphertext multiple of 16 bytes, and in a way that the decryption algorithm will understand that it has to ignore some data.

In any case, I strongly suggest that you stop right now what you are doing and go study some very introductory material on cryptography. For instance, check Crypto I on Coursera. You should understand very well the implications of choosing one mode or another, what are their strengths and, most importantly, their weaknesses. Without this knowledge, it is very easy to build systems which are very easy to break.


Update: based on your comments on the question, don't ever encrypt passwords when storing them at a database!!!!! You should never, ever do this. You must HASH the passwords, properly salted, which is completely different from encrypting. Really, please, don't do what you are trying to do... By encrypting the passwords, they can be decrypted. What this means is that you, as the database manager and who knows the secret key, you will be able to read every password stored in your database. Either you knew this and are doing something very, very bad, or you didn't know this, and should get shocked and stop it.

How to find file accessed/created just few minutes ago

Simply specify whether you want the time to be greater, smaller, or equal to the time you want, using, respectively:

find . -cmin +<time>
find . -cmin -<time>
find . -cmin  <time>

In your case, for example, the files with last edition in a maximum of 5 minutes, are given by:

find . -cmin -5

HTML5 Canvas: Zooming

Building on the suggestion of using drawImage you could also combine this with scale function.

So before you draw the image scale the context to the zoom level you want:

ctx.scale(2, 2) // Doubles size of anything draw to canvas.

I've created a small example here http://jsfiddle.net/mBzVR/4/ that uses drawImage and scale to zoom in on mousedown and out on mouseup.

'mvn' is not recognized as an internal or external command,

Add maven directory /bin to System variables under the name Path.

To check this, you can echo %PATH%

Ignore case in Python strings

This is how you'd do it with re:

import re
p = re.compile('^hello$', re.I)
p.match('Hello')
p.match('hello')
p.match('HELLO')

How to get value of a div using javascript

Value is not a valid attribute of DIV

try this

var divElement = document.getElementById('demo');
alert( divElement .getAttribute('value'));

Find if a textbox is disabled or not using jquery

.prop('disabled') will return a Boolean:

var isDisabled = $('textbox').prop('disabled');

Here's the fiddle: http://jsfiddle.net/unhjM/

MySQL skip first 10 results

Use LIMIT with two parameters. For example, to return results 11-60 (where result 1 is the first row), use:

SELECT * FROM foo LIMIT 10, 50

For a solution to return all results, see Thomas' answer.

How to clear the interpreter console?

You have number of ways doing it on Windows:

1. Using Keyboard shortcut:

Press CTRL + L

2. Using system invoke method:

import os
cls = lambda: os.system('cls')
cls()

3. Using new line print 100 times:

cls = lambda: print('\n'*100)
cls()

Find the index of a dict within a list, by matching the dict's value

Seems most logical to use a filter/index combo:

names=[{}, {'name': 'Tom'},{'name': 'Tony'}]
names.index(filter(lambda n: n.get('name') == 'Tom', names)[0])
1

And if you think there could be multiple matches:

[names.index(n) for item in filter(lambda n: n.get('name') == 'Tom', names)]
[1]

How to create a unique index on a NULL column?

It is possible to use filter predicates to specify which rows to include in the index.

From the documentation:

WHERE <filter_predicate> Creates a filtered index by specifying which rows to include in the index. The filtered index must be a nonclustered index on a table. Creates filtered statistics for the data rows in the filtered index.

Example:

CREATE TABLE Table1 (
  NullableCol int NULL
)

CREATE UNIQUE INDEX IX_Table1 ON Table1 (NullableCol) WHERE NullableCol IS NOT NULL;

Error in launching AVD with AMD processor

You need to read (and post) the output of

sc query intelhaxm

as stated on http://developer.android.com/tools/devices/emulator.html#accel-vm

You open a command prompt window by right click on the start menu, choose execute and write 'cmd'.

See also Android Emulator Doesn't Use HAXM .

If you cannot get the emulator to work you might want to try out an easier alternative: Genymotion - http://genymotion.com/

resize2fs: Bad magic number in super-block while trying to open

resize2fs Command will not work for all file systems.

Please confirm the file system of your instance using below command. enter image description here

Please follow the procedure to expand volume by following the steps mentioned in Amazon official document for different file systems.

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/recognize-expanded-volume-linux.html

Default file system in Centos is xfs, use the following command for xfs file system to increase partition size.

sudo xfs_growfs -d /

then "df -h" to check.

What is the scope of variables in JavaScript?

A very common issue not described yet that front-end coders often run into is the scope that is visible to an inline event handler in the HTML - for example, with

<button onclick="foo()"></button>

The scope of the variables that an on* attribute can reference must be either:

  • global (working inline handlers almost always reference global variables)
  • a property of the document (eg, querySelector as a standalone variable will point to document.querySelector; rare)
  • a property of the element the handler is attached to (like above; rare)

Otherwise, you'll get a ReferenceError when the handler is invoked. So, for example, if the inline handler references a function which is defined inside window.onload or $(function() {, the reference will fail, because the inline handler may only reference variables in the global scope, and the function is not global:

_x000D_
_x000D_
window.addEventListener('DOMContentLoaded', () => {_x000D_
  function foo() {_x000D_
    console.log('foo running');_x000D_
  }_x000D_
});
_x000D_
<button onclick="foo()">click</button>
_x000D_
_x000D_
_x000D_

Properties of the document and properties of the element the handler is attached to may also be referenced as standalone variables inside inline handlers because inline handlers are invoked inside of two with blocks, one for the document, one for the element. The scope chain of variables inside these handlers is extremely unintuitive, and a working event handler will probably require a function to be global (and unnecessary global pollution should probably be avoided).

Since the scope chain inside inline handlers is so weird, and since inline handlers require global pollution to work, and since inline handlers sometimes require ugly string escaping when passing arguments, it's probably easier to avoid them. Instead, attach event handlers using Javascript (like with addEventListener), rather than with HTML markup.

_x000D_
_x000D_
function foo() {_x000D_
  console.log('foo running');_x000D_
}_x000D_
document.querySelector('.my-button').addEventListener('click', foo);
_x000D_
<button class="my-button">click</button>
_x000D_
_x000D_
_x000D_


On a different note, unlike normal <script> tags, which run on the top level, code inside ES6 modules runs in its own private scope. A variable defined at the top of a normal <script> tag is global, so you can reference it in other <script> tags, like this:

_x000D_
_x000D_
<script>_x000D_
const foo = 'foo';_x000D_
</script>_x000D_
<script>_x000D_
console.log(foo);_x000D_
</script>
_x000D_
_x000D_
_x000D_

But the top level of an ES6 module is not global. A variable declared at the top of an ES6 module will only be visible inside that module, unless the variable is explicitly exported, or unless it's assigned to a property of the global object.

_x000D_
_x000D_
<script type="module">_x000D_
const foo = 'foo';_x000D_
</script>_x000D_
<script>_x000D_
// Can't access foo here, because the other script is a module_x000D_
console.log(typeof foo);_x000D_
</script>
_x000D_
_x000D_
_x000D_

The top level of an ES6 module is similar to that of the inside of an IIFE on the top level in a normal <script>. The module can reference any variables which are global, and nothing can reference anything inside the module unless the module is explicitly designed for it.

pip installation /usr/local/opt/python/bin/python2.7: bad interpreter: No such file or directory

In my case, I decided to remove the homebrew python installation from my mac as I already had two other versions of python installed on my mac through MacPorts. This caused the error message.

Reinstalling python through brew solved my issue.

What is a software framework?

In General, A frame Work is real or Conceptual structure of intended to serve as a support or Guide for the building some thing that expands the structure into something useful...

Using logging in multiple modules

Best practice is, in each module, to have a logger defined like this:

import logging
logger = logging.getLogger(__name__)

near the top of the module, and then in other code in the module do e.g.

logger.debug('My message with %s', 'variable data')

If you need to subdivide logging activity inside a module, use e.g.

loggerA = logging.getLogger(__name__ + '.A')
loggerB = logging.getLogger(__name__ + '.B')

and log to loggerA and loggerB as appropriate.

In your main program or programs, do e.g.:

def main():
    "your program code"

if __name__ == '__main__':
    import logging.config
    logging.config.fileConfig('/path/to/logging.conf')
    main()

or

def main():
    import logging.config
    logging.config.fileConfig('/path/to/logging.conf')
    # your program code

if __name__ == '__main__':
    main()

See here for logging from multiple modules, and here for logging configuration for code which will be used as a library module by other code.

Update: When calling fileConfig(), you may want to specify disable_existing_loggers=False if you're using Python 2.6 or later (see the docs for more information). The default value is True for backward compatibility, which causes all existing loggers to be disabled by fileConfig() unless they or their ancestor are explicitly named in the configuration. With the value set to False, existing loggers are left alone. If using Python 2.7/Python 3.2 or later, you may wish to consider the dictConfig() API which is better than fileConfig() as it gives more control over the configuration.

Typescript input onchange event.target.value

An alternative that has not been mentioned yet is to type the onChange function instead of the props that it receives. Using React.ChangeEventHandler:

const stateChange: React.ChangeEventHandler<HTMLInputElement> = (event) => {
    console.log(event.target.value);
};

How to use Javascript to read local text file and read line by line?

Without jQuery:

document.getElementById('file').onchange = function(){

  var file = this.files[0];

  var reader = new FileReader();
  reader.onload = function(progressEvent){
    // Entire file
    console.log(this.result);

    // By lines
    var lines = this.result.split('\n');
    for(var line = 0; line < lines.length; line++){
      console.log(lines[line]);
    }
  };
  reader.readAsText(file);
};

HTML:

<input type="file" name="file" id="file">

Remember to put your javascript code after the file field is rendered.

Can't connect to localhost on SQL Server Express 2012 / 2016

According to Aaron Bertand:

  1. You need to verify that the SQL Server service is running. You can do this by going to Start > Control Panel > Administrative Tools > Services, and checking that the service SQL Server (SQLEXPRESS) is running. If not, start it.

  2. While you're in the services applet, also make sure that the service SQL Browser is started. If not, start it.

  3. You need to make sure that SQL Server is allowed to use TCP/IP or named pipes. You can turn these on by opening the SQL Server Configuration Manager in Start > Programs > Microsoft SQL Server 2012 > Configuration Tools (or SQL Server Configuration Manager), and make sure that TCP/IP and Named Pipes are enabled. If you don't find the SQL Server Configuration Manager in the Start Menu you can launch the MMC snap-in manually. Check SQL Server Configuration Manager for the path to the snap-in according to your version.

    SQL Server Configuration Manager

  4. Verify your SQL Server connection authentication mode matches your connection string:

    • If you're connecting using a username and password, you need to configure SQL Server to accept "SQL Server Authentication Mode":

      -- YOU MUST RESTART YOUR SQL SERVER AFTER RUNNING THIS!
      USE [master]
      GO
      DECLARE @SqlServerAndWindowsAuthenticationMode INT = 2;
      EXEC xp_instance_regwrite
        N'HKEY_LOCAL_MACHINE',
        N'Software\Microsoft\MSSQLServer\MSSQLServer',
        N'LoginMode',
        REG_DWORD,
        @SqlServerAndWindowsAuthenticationMode;
      GO
      
    • If you're connecting using "Integrated Security=true" (Windows Mode), and this error only comes up when debugging in web applications, then you need to add the ApplicationPoolIdentity as a SQL Server login:
  5. otherwise, run Start -> Run -> Services.msc If so, is it running?

If it's not running then

It sounds like you didn't get everything installed. Launch the install file and chose the option "New installation or add features to an existing installation". From there you should be able to make sure the database engine service gets installed.

Submit Button Image

It's very important for accessibility reasons that you always specify value of the submit even if you are hiding this text, or if you use <input type="image" .../> to always specify alt="" attribute for this input field.

Blind people don't know what button will do if it doesn't contain meaningful alt="" or value="".

How do I count unique items in field in Access query?

Try this

SELECT Count(*) AS N
FROM
(SELECT DISTINCT Name FROM table1) AS T;

Read this for more info.

Java Can't connect to X11 window server using 'localhost:10.0' as the value of the DISPLAY variable

I was using Xming and got similar error. Following steps were taken to fix the issue:

  1. In Xming launch check the box no access control.
  2. In putty ran the following command: DISPLAY=XXX.XXX.XXX.XX:0.0; export DISPLAY

Replace XXX.XXX.XXX.XX with your IP address.