These states are the same as mentioned in the [`Thread.State`][1] enum. &quot;Wait&quot; means, as the documentation says:

&gt; A thread is in the waiting state due to calling one of the following methods:
&gt;
&gt; * Object.wait with no timeout
&gt; * Thread.join with no timeout
&gt; * LockSupport.park

&quot;Monitor&quot; is the **`BLOCKED`** state, in which the thread is waiting to obtain a lock on an object (because it&#39;s trying to enter a `synchronized` block or method while another thread already holds the associated lock).


  [1]: http://download.oracle.com/javase/1,5.0/docs/api/java/lang/Thread.State.html

That&#39;s not a &quot;monitoring&quot; status... It indicates that the thread is in the `Thread.State.BLOCKED` state. I see there is another good answer, i&#39;ll just point you to [this link](http://geekexplains.blogspot.com/2008/07/threadstate-in-java-blocked-vs-waiting.html) for deeper explanation

Monitor will mean the thread is waiting to attain a lock on an object.  For example when one thread is running a synchronized method and another one tries to invoke it on the same object, it will not be able to until the first invocation of the method is finished.  This is because the first thread has a monitor or lock on that object, so the second one must wait until it is released. &lt;/b&gt;

From [Oracle Threading Tutorials][1]:

&gt; &quot;Synchronization is built around an internal entity known as the intrinsic lock or monitor lock. (The API specification often refers to this entity simply as a &quot;monitor.&quot;) Intrinsic locks play a role in both aspects of synchronization: enforcing exclusive access to an object&#39;s state and establishing happens-before relationships that are essential to visibility.&quot;


  [1]: http://download.oracle.com/javase/tutorial/essential/concurrency/locksync.html

I need to pull in a specific pull request (that hasn&#39;t been processed into the main stream yet) in the NServiceBus repo:

https://github.com/johnsimons/NServiceBus/commit/d8524d53094e8181716e771c1023e968132abc15

It&#39;s obviously not my repo, but I need the changes that exist in that pull request.

What is the best way to do this?

How can I fetch an unmerged pull request for a branch I don&#39;t own?

I want to set disable attribute based on a condition for Html.TextBoxFor in asp.net MVC like below

    @Html.TextBoxFor(model =&gt; model.ExpireDate, new { style = &quot;width: 70px;&quot;, maxlength = &quot;10&quot;, id = &quot;expire-date&quot; disabled = (Model.ExpireDate == null ? &quot;disable&quot; : &quot;&quot;) })

This helper has two output disabled=&quot;disabled &quot; or disabled=&quot;&quot;. both of theme make the textbox disable.

I want to disable the textbox if Model.ExpireDate == null else I want to enable it

Set disable attribute based on a condition for Html.TextBoxFor

![enter image description here][1]


  [1]: http://i.stack.imgur.com/jou0Z.jpg

I use visualVM connect a multi thread Java application, thread has 4 status, namely running, sleeping, wait, Monitor. What does this Monitoring status mean? What&#39;s the difference between wait and Monitor?

Java JVM profiling, thread status - what does &quot;Monitor&quot; status mean?

<p><img src="http://i.stack.imgur.com/jou0Z.jpg" alt="enter image description here"></p>
<p>I use visualVM connect a multi thread Java application, thread has 4 status, namely running, sleeping, wait, Monitor. What does this Monitoring status mean? What's the difference between wait and Monitor?</p>


Lots of Java books describe the `switch` statement as being faster than the `if else` statement. But I did not find out anywhere **why switch is faster than if**.

Example
-------
I have a situation I have to choose any one item out of two. I can use either use

    switch (item) {
        case BREAD:
            //eat Bread
            break;
        default:
            //leave the restaurant
    }

or

    if (item == BREAD) {
        //eat Bread
    } else {
        //leave the restaurant
    }

considering item and BREAD is a constant int value.

In the above example which **is faster in action and why?**


Why switch is faster than if

I have String array with some components, this array has 5 components and it vary some times. What I would like to do is to iterate through that array and get the first component and the component next to that one. So the first time I would get the component number one and the component number 2, the second time would get the number 2 and 3, the third time number 3 and 4... And so on until you get to the last component. 

This how far I have come: 


    String[] elements = { &quot;a&quot;, &quot;a&quot;,&quot;a&quot;,&quot;a&quot; };
        
    for( int i = 0; i &lt;= elements.length - 1; i++)
    {
        // get element number 0 and 1 and put it in a variable, 
        // and the next time get element      1 and 2 and put this in another variable. 
    }


How can I accomplish this?




Iterate through string array in Java

I want to copy text from a `JTable`&#39;s cell to the clipboard, making it available to be pasted into other programs such as Microsoft Word. I have the text from the `JTable`, but I am unsure how to copy it to the clipboard.


Copying text to the clipboard using Java

I&#39;m making a Java Swing application that has the following layout ([`MigLayout`][1]):

    [icon][icon][icon][....]
    where icon = jlabel and the user can add more icons

When the user adds or removes icons, the others should shrink or grow.

My question is really straightforward: I have a `JLabel` which contains an `ImageIcon`; how can I resize this icon?

  [1]: http://www.miglayout.com/

How to resize JLabel ImageIcon?

There seems to be a lot of different implementations and ways to generate thread-safe Sets in Java.
Some examples include

1) [CopyOnWriteArraySet][1] 

2) [Collections.synchronizedSet(Set&lt;T&gt; set)][2]

3) [ConcurrentSkipListSet][3]

4) [Collections.newSetFromMap(new ConcurrentHashMap&lt;Object,Boolean&gt;())][4]

5) Other Sets generated in a way similar to (4) 

These examples come from [Concurrency Pattern: Concurrent Set implementations in Java 6][5]

Could someone please simply explain the differences, advantages, and disadvantage of these examples and others? I&#39;m having trouble understanding and keeping straight everything from the Java Std Docs.


  [1]: http://download.oracle.com/javase/6/docs/api/java/util/concurrent/CopyOnWriteArraySet.html
  [2]: http://download.oracle.com/javase/6/docs/api/java/util/Collections.html
  [3]: http://download.oracle.com/javase/6/docs/api/java/util/concurrent/ConcurrentSkipListSet.html
  [4]: http://download.oracle.com/javase/6/docs/api/java/util/Collections.html
  [5]: https://dhruba.wordpress.com/2009/08/05/concurrent-set-implementations-in-java-6/

Different types of thread-safe Sets in Java

I have a program which interfaces with a radio I am using via a gui I wrote in PyQt.  Obviously one of the main functions of the radio is to transmit data, but to do this continuously, I have to loop the writes, which causes the gui to hang. Since I have never dealt with threading, I tried to get rid of these hangs using `QCoreApplication.processEvents().` The radio needs to sleep between transmissions, though, so the gui still hangs based on how long these sleeps last.  

Is there a simple way to fix this using QThread?  I have looked for tutorials on how to implement multithreading with PyQt, but most of them deal with setting up servers and are much more advanced than I need them to be.  I honestly don&#39;t even really need my thread to update anything while it is running, I just need to start it, have it transmit in the background, and stop it.



Background thread with QThread in PyQt

The function `foo` below returns a string `&#39;foo&#39;`. How can I get the value `&#39;foo&#39;` which is returned from the thread&#39;s target?

    from threading import Thread

    def foo(bar):
        print(&#39;hello {}&#39;.format(bar))
        return &#39;foo&#39;
    
    thread = Thread(target=foo, args=(&#39;world!&#39;,))
    thread.start()
    return_value = thread.join()

The &quot;one obvious way to do it&quot;, shown above, doesn&#39;t work: `thread.join()` returned `None`.

How to get the return value from a thread in Python?

I use ScheduledExecutorService to execute a method periodically.

p-code:

    ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
    ScheduledFuture&lt;?&gt; handle =
    	    scheduler.scheduleWithFixedDelay(new Runnable() {
    	         public void run() { 
    	             //Do business logic, may Exception occurs
    	         }
    	    }, 1, 10, TimeUnit.SECONDS);


My question:

How to continue the scheduler, if `run()` throws Exception? 
Should I try-catch all Exception in method `run()`? Or any built-in callback method to handle the Exception? Thanks!


ScheduledExecutorService Exception handling

A warning is showing every time I synchronize on a non-final class field. Here is the code:  

    public class X  
    {  
       private Object o;  
         
       public void setO(Object o)  
       {  
         this.o = o;  
       }  
        
       public void x()  
       {  
         synchronized (o) // synchronization on a non-final field  
         {  
         }  
       }  
     } 

so I changed the coding in the following way:
  

     public class X  
     {  
       
       private final Object o;       
       public X()
       {  
         o = new Object();  
       }  
        
       public void x()  
       {  
         synchronized (o)
         {  
         }  
       }  
     }  

I am not sure the above code is the proper way to synchronize on a non-final class field. How can I synchronize a non final field? 

Synchronization of non-final field

If I have a serial queue, how can I, from the main thread, tell it to immediately stop execution and cancel all of its tasks?

How to stop the execution of tasks in a dispatch queue?

Are there currently (Java 6) things you can do in Java bytecode that you can&#39;t do from within the Java language?

I know both are Turing complete, so read &quot;can do&quot; as &quot;can do significantly faster/better, or just in a different way&quot;.

I&#39;m thinking of extra bytecodes like `invokedynamic`, which can&#39;t be generated using Java, except that specific one is for a future version.

Bytecode features not available in the Java language

I profile running Java applications often with VisualVM but it needs X to run on the machine.

I know I can connect through management port but that will be an offline sampled profiling which is not enough for me.

So I&#39;m looking for a solution with which I can profile the CPU usage of the methods of a running Java application from command-line. It&#39;s enough for me to collect data on the server and then the collected data can be analyzed on a different machine.

*Update:*

It seems I need to be more specific. I want to profile a running Java application from command line, I don&#39;t want to stop it and rerun it.

Profiling a running Java application in command line

I&#39;m wondering if there is some way to make Haskell run on the JVM (compiled or interpreted)?

There exists JHaskell on Sourceforge but this one seems to be empty and dead.

GHC uses LLVM as compiler backend. Would it be a good idea or possible to compile LLVM to Java bytecode? Or maybe use a different compiler backend?


Haskell on JVM?

I am getting this error message when I start Eclipse Helios on Windows 7:

&gt; Failed to create the Java Virtual Machine

![Enter image description here][1]

My eclipse.ini looks as follows:

    -startup
    plugins/org.eclipse.equinox.launcher_1.1.0.v20100507.jar
    -vm
    P:\Programs\jdk1.6\bin
    --launcher.library
    plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.1.0.v20100503
    -product
    org.eclipse.epp.package.jee.product
    --launcher.defaultAction
    openFile
    -showsplash
    org.eclipse.platform
    --launcher.XXMaxPermSize
    512m
    --launcher.defaultAction
    openFile
    -vmargs
    -Dosgi.requiredJavaVersion=1.5
    -Xms120m
    -Xmn100m
    -Xmx1024m

My JAVA_HOME is correctly set as far as I can tell. How can I fix this?

Things I have tried so far:
---------------------------

 1. Adding the full path to javaw.exe
   `-vm
    P:\Programs\jdk1.6\bin\\bin\javaw.exe`
 2. Removing the `-vm` option altogether
 3. Removing `--launcher.XXMaxPermSize` fixes the issue, but it causes permgen errors
 4. Removing the value `512` of `--launcher.XXMaxPermSize` fixes the issue, but it causes permgen errors
 5. Reducing `-Xmx` to `512m` also fixes the issue.

Why can I not use &#39;1024m&#39; for &#39;-Xmx&#39; and &#39;--launcher.XXMaxPermSize&#39;?

  [1]: http://i.stack.imgur.com/YYgjc.png


Eclipse error: &#39;Failed to create the Java Virtual Machine&#39;

Given the following constructs for defining a function in Scala, can you explain what the difference is, and what the implications will be?

    def foo = {}

vs.

    def foo() = {}


*Update*

Thanks for the quick responses.  These are great.  The only question that remains for me is:

If I omit the parenthesis, is there still a way to pass the function around?  This is what I get in the repl:

    scala&gt; def foo = {}
    foo: Unit
    
    scala&gt; def baz() = {}
    baz: ()Unit
    
    scala&gt; def test(arg: () =&gt; Unit) = { arg }
    test: (arg: () =&gt; Unit)() =&gt; Unit
    
    scala&gt; test(foo)
    &lt;console&gt;:10: error: type mismatch;
     found   : Unit
     required: () =&gt; Unit
                  test(foo)
                       ^
    
    scala&gt; test(baz)
    res1: () =&gt; Unit = &lt;function0&gt;
    
----------

***Update 2012-09-14***

Here are some similar questions I noticed:

 1. https://stackoverflow.com/q/7600910/293064
 2. https://stackoverflow.com/q/6939908/293064

Content Type	Original Author	Original Content on Stackoverflow
Question	user84592	View Question on Stackoverflow
Solution 1 - Java	Jesper	View Answer on Stackoverflow
Solution 2 - Java	Grooveek	View Answer on Stackoverflow
Solution 3 - Java	mogronalol	View Answer on Stackoverflow

Java JVM profiling, thread status - what does "Monitor" status mean?

Java Problem Overview

Java Solutions

Solution 1 - Java

Solution 2 - Java

Solution 3 - Java

Set disable attribute based on a condition for Html.TextBoxFor

How can I fetch an unmerged pull request for a branch I don't own?

Attributions