Open the Console view, locate the console for your running app and hit the Big Red Button.

Alternatively if you open the Debug perspective you will see all running apps in (by default) the top left. You can select the one that&#39;s causing you grief and once again hit the Big Red Button.![enter image description here][1]


  [1]: http://i.stack.imgur.com/17IXM.png

For newer versions of Eclipse:

1. open the Debug perspective (Window &gt; Open Perspective &gt; Debug) 

2. select process in Devices list (bottom right)

3. Hit Stop button (top right of Devices pane)



I have a .bat file on my quick task bar (windows) with:

    taskkill /F /IM java.exe

It&#39;s very quick, but it may not be good in many situations!

The easiest way to do this is to click on the Terminate button(red square) in the console:

![enter image description here][1]


  [1]: http://i.stack.imgur.com/YII3c.png

For Eclipse:
menu bar-&gt; window -&gt; show view then find &quot;debug&quot; option if not in list then select other ... 

new window will open and then search using keyword &quot;debug&quot; -&gt; select debug from list

it will added near console tab.
use debug tab to terminate and remove previous executions. ( right clicking on executing process will show you many option including terminate)


I&#39;m looking for a way of getting an SHA-1 checksum with a Java byte array as the message.

Should I use a third party tool or is there something built in to the JVM that can help?




Compute SHA-1 of byte array

It&#39;s legal to do this in Java:

     void spew(Appendable x)
     {
         x.append(&quot;Bleah!\n&quot;);
     }

How can I do this (syntax not legal):

     void spew(Appendable &amp; Closeable x)
     {
         x.append(&quot;Bleah!\n&quot;);
         if (timeToClose())
             x.close();
     }

**I would like if possible to force callers to use objects that are both Appendable and Closeable, without requiring a specific type.** There are multiple standard classes that do this, e.g. BufferedWriter, PrintStream, etc.

If I define my own interface

     interface AppendableAndCloseable extends Appendable, Closeable {}

that won&#39;t work since the standard classes that implement Appendable and Closeable do not implement my interface AppendableAndCloseable (unless I don&#39;t understand Java as well as I think I do... empty interfaces still add uniqueness above and beyond their superinterfaces).

The closest I can think of is to do one of the following:

 1. pick one interface (e.g. Appendable), and use runtime tests to ensure the argument is an `instanceof` the others. Downside: problem not caught at compile time.

 2. require multiple arguments (catches compile-time correctness but looks dorky):

        void spew(Appendable xAppend, Closeable xClose)
        {
            xAppend.append(&quot;Bleah!\n&quot;);
            if (timeToClose())
                xClose.close();
        }



How can I require a method argument in Java to implement multiple interfaces?

Sometimes, I&#39;ll run a program that accidentally contains an infinite loop or something. Eclipse will let me continue editing the program, but be super slow. How can I stop it? (Do I want to restart the JVM?) Restarting eclipse itself always works, but that breaks my workflow.

Eclipse: stop code from running (java)

<p>Sometimes, I'll run a program that accidentally contains an infinite loop or something. Eclipse will let me continue editing the program, but be super slow. How can I stop it? (Do I want to restart the JVM?) Restarting eclipse itself always works, but that breaks my workflow.</p>


I want to join a `String[]` with a glue string. Is there a function for this?

Java function for arrays like PHP&#39;s join()?

I want to read and write an Excel file from Java with 3 columns and N rows, printing one string in each cell.  Can anyone give me simple code snippet for this? Do I need to use any external lib or does Java have built-in support for it?

I want to do the following:

    for(i=0; i &lt;rows; i++)
         //read [i,col1] ,[i,col2], [i,col3]
    
    for(i=0; i&lt;rows; i++)
        //write [i,col1], [i,col2], [i,col3]



How to read and write excel file

I understand that the String class&#39; [hashCode()][1] method is *not* guarantied to generate unique hash codes for distinct String-s.  I see a lot of usage of putting String keys into HashMap-s (using the default String hashCode() method).  A lot of this usage could result in significant application issues if a map `put` displaced a HashMap entry that was previously put onto the map with a truely distinct String key.  

What are the odds that you will run into the scenario where String.hashCode() returns the same value for distinct String-s?  How do developers work around this issue when the key is a String?


  [1]: http://java.sun.com/j2se/1.4.2/docs/api/java/lang/String.html#hashCode()

Bad idea to use String key in HashMap?

I need to randomly shuffle the following Array:

    int[] solutionArray = {1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1};

Is there any function to do that?

Random shuffling of an array

I am using Eclipse PDT 3.5 on Vista (32 bit). It works, though eclipse needs admin rights to execute. This annoys me, but I accept it.

But: every now and then (I am not sure, it may even be everytime I want to open a project), I get the error message &quot;The project description file (.project) for *my project* is missing.&quot;. 

It is NOT missing, it is in the main folder of the project. It has no special flags set (it is not hidden, nor system file, nor write-protected).

This is for ALL projects I have in my list. The only solution I have found so far is to delete the project from eclipse an re-add it. This is somewhat annoying.

What can I do?

EDIT: The workspaces are on a server volume. Can this be the problem? I used Eclipse 3.3 before, and there it was no problem with the server paths. And the server volume is mapped to a drive letter.

The project description file (.project) for my project is missing

I have added a second Virtual Device to test a different screen resolution (QVGA), but now I wanna switch back to the first AVD (HVGA) again. How can I set the virtual device in Eclipse to be used by default or even specifically for my project? In the properties I can only set the API level.

I also couldn&#39;t find any information in the [command line tool documentation][1] to set this manually.


  [1]: http://developer.android.com/guide/developing/tools/avd.html

Android Emulator: select AVD (Android Virtual Device) to run by default

I often use the Eclipse feature (Galileo) of suggested error corrections to automatically create code stubs or to refactor things. For example, I would write a method that calls other methods which don&#39;t exist yet, then move the mouse over the error message and click on &quot;create method&quot;. Or, change `this` to the class name and choose &quot;add `static` modifier&quot; from the quick fixes.

I think this is very convenient because it lets me stay in one place in my code and sort of &quot;remotely&quot; wire up what&#39;s not currently visible on my screen. What I think is annoying though, is that I have to leave the keyboard, hover my mouse over the error symbol, wait for the tooltip to pop up, and click on the option (doing that, I sometimes move the mouse a little over the edge and the tooltip goes away again - very annoying).

Am I missing a faster method here? I can&#39;t seem to find a keyboard shortcut, but then I have overlooked stuff from the huge preference dialog before.

Faster way (keyboard shortcuts?) to use quick fixes in Eclipse?

- What do the icons in the Eclipse debugger mean?
- What do the icon decorators in Eclipse mean?
- What do the icons in Eclipse&#39;s Package Explorer mean?
- What do the little letters on top of Eclipse icons mean?
- What&#39;s the difference between the two error icons in Eclipse (the x in the red circle and the one with the light bulb)?

I just came to SO looking for this, didn&#39;t find it, and found it on my own elsewhere. But I thought it would be good for SO to have the answer for future reference; I wondered about them all the time when I was new to Eclipse (this was before I discovered SO).

What do the icons in Eclipse mean?

I&#39;m looking to find bottlenecks in my Java application in [Eclipse][1]. I&#39;m thinking this might be useful:

http://www.eclipse.org/projects/project_summary.php?projectid=tptp.performance

Any other good plug-ins to use?

**EDIT** OK, it doesn&#39;t necessarily have to be an Eclipse plug-in. But it would be nice. And, I&#39;m most interested in speed.

  [1]: http://en.wikipedia.org/wiki/Eclipse_(software)


Profiling a Java Application in Eclipse? (plug-in)

What is the difference between a thread&#39;s context class loader and a normal class loader?

That is, if `Thread.currentThread().getContextClassLoader()` and `getClass().getClassLoader()` return different class loader objects, which one will be used?

Difference between thread&#39;s context class loader and normal classloader

I have two applications running in the same java virtual machine, and both use different keystores and truststores.

A viable option would be use a single keystore and import all the other ones into the shared keystore (e.g. keytool -import), but it would really help my requirements if I could use separate keystores for separate applications running in the same jvm.

I could set the keystore and truststores to be used as jvm parameters or system properties as follows:

    java -Djavax.net.ssl.keyStore=serverKeys 
    -Djavax.net.ssl.keyStorePassword=password 
    -Djavax.net.ssl.trustStore=serverTrust 
    -Djavax.net.ssl.trustStorePassword=password SSLApplication

or

    System.setProperty(&quot;javax.net.ssl.keyStore&quot;,&quot;serverKeys&quot;)


But the problem with this approach is that it specifies the keystore/truststore to be used at a JVM level, thus all applications running in the same JVM gets the same keystore/truststore.

I have also tried creating a custom SSLContext and setting it as the default, but it also sets the context for all applications running in the same JVM.

    SSLContext context = SSLContext.getInstance(&quot;SSL&quot;);
    context.init(kms, tms, null);
    SSLContext.setDefault(context);

I want to be able use different keystores/truststores without modifying individual application codes. 

**A solution that can *dynamically register multiple key stores* in addition to the default keystore/certs in jre into jvm would be great.**

    
 The solution will work in this way: 
    
 - When JVM boots, it loads all the default certs/keystores 
    from jre/certs folder (default java behaviour when no keystores specified).
 - When App 1 loads it registers its keystores, 
 - then when App 2 loads it registers its keystores...


Please let me know your ideas or solutions.
Thanks in advance!

Registering multiple keystores in JVM

How do I distinguish running Java threads and native threads?

In Linux there will be Parent process for every child process, and they say 0 is the parent of all the process, will there be a Parent thread of all the forked Java threads?

How do I know which Java thread is related to OS thread (if a Java thread forkes a native process thread).

Is there any naming convention of Java threads and OS threads?

Can a running Java threads can be suspended or killed from another Java code?

Distinguishing between Java threads and OS threads?

Please take a look at the picture below.
When we create an object in java with the `new` keyword, we are getting a memory address from the OS.

When we write `out.println(objName)` we can see a &quot;special&quot; string as output. My questions are:

1. What is this output?
2. If it is memory address which given by OS to us:

 a) How can I convert this string to binary?

 b) How can I get one integer variables address?

![alt text][1]


  [1]: https://content.screencast.com/users/uzay95/folders/Jing/media/f3caf9f8-b109-41d4-a477-0ad7c10504ce/2009-12-25_1456.png

Memory address of variables in Java

The canonical JVM implementation from Sun applies some pretty sophisticated optimization to bytecode to obtain near-native execution speeds after the code has been run a few times. 

The question is, why isn&#39;t this compiled code cached to disk for use during subsequent uses of the same function/class?

As it stands, every time a program is executed, the JIT compiler kicks in afresh, rather than using a pre-compiled version of the code. Wouldn&#39;t adding this feature add a significant boost to the initial run time of the program, when the bytecode is essentially being interpreted?

Content Type	Original Author	Original Content on Stackoverflow
Question	Nick Heiner	View Question on Stackoverflow
Solution 1 - Java	SCdF	View Answer on Stackoverflow
Solution 2 - Java	Snowcrash	View Answer on Stackoverflow
Solution 3 - Java	Oliveira	View Answer on Stackoverflow
Solution 4 - Java	Tia	View Answer on Stackoverflow
Solution 5 - Java	Hari Kanure	View Answer on Stackoverflow

Eclipse: stop code from running (java)

Java Problem Overview

Java Solutions

Solution 1 - Java

Solution 2 - Java

Solution 3 - Java

Solution 4 - Java

Solution 5 - Java

How can I require a method argument in Java to implement multiple interfaces?

Compute SHA-1 of byte array

Attributions