What is an alternate to Thread.Sleep()?

What is an alternate to thread.sleep? The reason being, my action listener won't let me throw exceptions so I need an alternative to thread.sleep, anything?

watwatacrazy wrote:
What is an alternate to thread.sleep? The reason being, my action listener won't let me throw exceptions so I need an alternative to thread.sleep, anything?I am in no way condoning this idea, because as mentioned it is a very bad idea.
However. Not lettiing you throw exceptions is not a reason to not do something. All it means is that you need a catch block. You should review the exceptions part of the Java tutorial found here [_Java Tutorial : Exceptions_|http://java.sun.com/docs/books/tutorial/essential/exceptions/index.html]

Similar Messages

What's wrong to put Thread.sleep in a session bean?

i am working on a trading platform and i think there is a design flaw. The part i am working on is the Order Management module. When an order value object is published to a JMS topic and picked up by a MDB. The MDB, in turn, calls a session bean (could be stateless, I didn't check), OrderEngineBean. After this bean saves the order vo into database and broadcast the message to all involved parties, it suspends for 12 sec, using Thread.sleep, so other parities might have a chance to update the vo. If no update occurs, the order is considered expired and abandoned.
It looks awkward to me to use a Thread.sleep in a session, but I haven't come out with a better idea to deal with the scenario like above.
Anyone can help me out?
Thanks a lot!
Sway

Setting the property "max-beans-in-free-pool" is not the answer to this issue. By setting this property to 1, the container merely instantiates and keeps one instance of the bean in the free pool at the "start" of the app server. But if the container comes across more than one requests for the same EJB simultaneoulsy, then it will create new instances at that time to handle the requests simultaneously.
You are seeing intermixed log messages between two threads because these messages are being logged from two different instances of the EJB and NOT the same instance of the EJB. The container does synchronizes the calls on "a method" on "a instance". So what you are seeing are the messages coming from "a method" on "two different instances" of the same EJB.
You can refer to the EJB 2.0 specification section 6.11.6 Non-reentrant instances for details about simultaneous access to the same session object.

Thread.yield() and Thread.sleep(), what's the difference

Folks'es,
can anyone enlighten me, as to the difference between yield() and sleep() in the Thread class?
i know, with sleep, one can specify the amount of time to sleep, but does that mean the thread yields for that amount of time?
if i use yield(), how long will my thread stop running?
any information is appreciated
thomas

Thread.yield() is used to give other threads a chance to get a processor time slice, according to the thread dispatcher rules. If there are no other threads ready to run, the current thread will gain the processor again.
Thread.sleep() will always release the processor for at least the amount of time specified, even if there are no other threads requesting it.

Mouse events during Thread.sleep

hi.
I have an applet .
I have a alghoritm simulator.
Everytime I find a solution I call the method Thread.sleep .
I want to pause the application and I create a JToggleButton Pause .
When I press the Pause during sleep mouse event are managed at the end of alghoritm.
How can I manage mouse events during sleep?

All UI events (such as mouse events) occur on the event dispatch thread (EDT).
That means if you sleep on the EDT, you lock up the UI. For this reason, you shouldn't be sleeping on the EDT.
I'm not sure what your sleep is trying to do but you need to manage your threads a little more carefully. For instance, any time consuming process which is invoked as a result of a UI event needs to be fired on a new thread to prevent the UI freezing. The fun starts when you have to update the UI as a result of that process, because you should then hook back onto the EDT to avoid the risk of deadlock.
Some utility classes are provided, such as SwingUtilities, and other example code is provided on Sun's site, such as SwingWorker - but if you do much UI work you'll probably end up with your own core set of threading tools and so on to make life easier.

What exactly is the main thread?

please consider this code:
public class Foo {
    public static void main(String[] args) {
          ((Foo) Thread.currentThread()).bar(); // <--- error. see stack trace below.
    public void bar() {
        System.out.println("--bar()--");
}stack trace: Exception in thread "main" java.lang.ClassCastException: java.lang.Thread cannot be cast to testingarea.Foo
So what does this say about the main entry thread? is it an instance of "Foo"? or an instance of java.lang.Thread? If an instance of "Foo" why can't I invoke an instance method on the return value of "Thread.currentThread()"? If the main thread is an instance of java.lang.Thread, then where is the:
"public void run();" method?
While I can't think of any practical usage of this knowledge yet, but I'd still like to know. Thanks.
Edited by: outekko on Mar 17, 2010 6:38 PM

joshg_75 wrote:
You should always refer to the javadoc for infomation of a method and its usage. In this case, refer to the javadoc of the Thread class.
http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Thread.html
I suggest you also read up on usage of threads.Can you please share a little of your expertise in threads?
Remember this is the "New To Java" forum, and I am just a beginner as you discovered. Any help from experts would be embraced. Before you became a thread expert, you must have started somewhere. I don't need immediate assistance, but whenever you get the time, why not cut/paste this into your IDE and take a look.
public class Main {
static ObjectOutputStream oos;
static ObjectInputStream ois;
public static void main(String[] args) {
    try {
      PipedInputStream pin = new PipedInputStream();
      PipedOutputStream pout = new PipedOutputStream(pin);
      oos = new ObjectOutputStream(pout);
      ois = new ObjectInputStream(pin);
      new OutThread().start();
      for(;;) {
        Thread t = (Thread) ois.readObject();
        t.start();
    } catch (Exception e) { e.printStackTrace(); }
      public static class OutThread extends Thread implements Serializable {
        public void run() {
          System.out.println("OutThread::run--> id# " + this.getId());
          try { Thread.sleep(1030); } catch (InterruptedException e) { }
          try {
            oos.writeObject(this);
            hangAround();
          } catch (Exception e) { e.printStackTrace(); }
        public void hangAround() {
          for (;;) {
            System.out.println("_____waiting around... id# " + this.getId());
            try { Thread.sleep(5030); } catch (InterruptedException e) { }
}Not only do I appear to serialize instances of threads, the threads are actually running . So, does a live thread have private, non-transient, "state" that needs to be persisted? If so, why does serialization work? If not, why not write in the API that java.lang.Thread implements Serializable ? Whatever understanding (if any) I had of threads has melted to nothing. I am struggling with your field of expertise; please help me get back on track. Any assistance embraced.
ps. don't offer friendly criticism by scolding my design of serialized threads. My only goal is to see if I can do it (and learn something along the way).

Confusion using Thread.sleep() method

I tried it in this program
class NewThread implements Runnable {
String name; // name of thread
Thread t;
NewThread(String threadname) {
    name = threadname;
    t = new Thread(this, name);
    System.out.println("New thread: " + t);
    t.start(); // Start the thread
// This is the entry point for thread.
public void run() {
    try {
      for(int i = 5; i > 0; i--) {
        System.out.println(name + ": " + i);
        Thread.sleep(1000);
    } catch (InterruptedException e) {
      System.out.println(name + "Interrupted");
    System.out.println(name + " exiting.");
class MultiThreadDemo {
public static void main(String args[]) {
    new NewThread("One"); // start threads
    new NewThread("Two");
    new NewThread("Three");
    try {
      // wait for other threads to end
      Thread.sleep(10000);
    } catch (InterruptedException e) {
      System.out.println("Main thread Interrupted");
    System.out.println("Main thread exiting.");
}the output is
one: 5
two: 5
three 5
delay of 1 second
one:4
two: 4
three: 4
delay of 1second
what all i know about sleep() is that it pause the currently executing thread for specified time. hence in above program when first thread runs and prints value 5 then it should get paused for 1 second cause there is Thread.sleep(1000) after println() statement.
and output should be
one: 5
delay of 1 second
two: 5
delay of 1 second
three: 5
delay of 1 second
but this is not actually happens. may be i am wrong about Thread.sleep method() or something else.
would you guys please clear it?
regards
san

Thread.sleep() only sleeps the current thread. As each thread runs concurrently they all print concurrently and all sleep concurrently.

Alternative to Thread.Sleep in catch?

Is there any other way to make the code wait than using Thread.Sleep in catch, because Thread.Sleep disturbs other objects on my form. Here is what I'm trying to do:
Try{
//do something
catch
// wait 10 seconds
//retry

Timers are a bit of a nuisance what with keeping your form in memory even when you try and dispose the things.
You could push the thing you're doing onto another thread.
Use async await.
You could then use Task.Delay.
A very simplified example:
private async void Button_Click1(object sender, RoutedEventArgs e)
await Task.Delay(2000);
// Do something
Because that's an async method processing returns to the caller when it hits the await.
That then pauses 2 seconds without impinging on your UI thread.
Before the separate thread continues with the code after your await.
You could put your try catch into a method like that and it'd do what you want without a timer.
10 seconds seems a bit of a short time by the way.
Hope that helps.
Recent Technet articles:
Property List Editing ;
Dynamic XAML

Updating frame content between Thread.sleep() calls

I have several JLabels in a Frame. What I want is to update the content of the labels (to be more precise, the ImageIcons), but with pauses in between each update (lets say 1 second). So, I want to change the content of one label, have those changes show on screen, then, wait for a second and change the content of the second label, show the changes, wait for a second, change the next label, and so on...
What I'm doing is:
change label 1
Thread.sleep(1000);
change label 2
Thread.sleep(1000);
change label 3
Thread.sleep(1000);
...And the problem is that the individual changes are not shown on screen until the whole process has finished. It does pause after each change, but the change to the particular label is not shown afterwards. Then, when the whole process is finished, the changes to all the labels are shown simultaneously on screen.
I have tried calling repaint() and validate() after each call to Thread.sleep(), but it makes no difference.
Why are the changes not updated on screen until the end?
How can I achieve what I'm trying to do?
Many thanks in advance.

You're sleeping in the main thread, so you're holding up the paint thread too...
I'd trying extending each label / visual component, to include it's own timer and thread.
eg. ( not compiled nor tested, but addresses all the main points... )
regards,
Owen
public class myLabel extends JLabel implements runnable
    boolean animate = true;
    Thread paintThread;
     public myLabel ( )
          super();
          paintThread = new Thread ( this );
     public void startAnimation ( )
          if ( animate == false )
             animate = true;
             paintThread.start();
     pubic void stopAnimation ( )
         animate = false;
     public void run ( )
           while ( !animate )
               Thread.sleep ( 1000 );
                final Runnable runnable = new Runnable()
                    public void run()
                          // change label text
                          // Make any Swing / GUI changes here
                    } // run
               };    // runnable
               // force/flag this label as requiring a repaint
               invalidate();
               // NB : You must use this to avoid multi-threaded problems with Swing
               SwingUtilities.invokeLater(runnable);
}

Realtime equivalent to Java's Thread.sleep()?

I have an application that I want to guarantee that when I call Java's Thread.sleep(n) the thread will sleep for precisely that amount of time, or close to it at least. What we recently encountered though was that if the "wall clock" time is changed in one thread while a sleep is occurring in another thread, this clock change will impact when the sleeping thread will wake up.
In our case, we had a simple Thread.sleep(1000), and during that one second period another thread set the clock back two minutes. The sleeping thread ended up sleeping roughly two minutes and a second instead of just a second. Apparently this is a "feature" of Thread.sleep(), and I can see in some cases (e.g. a task scheduler based on wall clock times) where this is exactly the behavior you'd want. However, in our case, we want the sleep function to sleep by the amount we specify, regardless of changes to the wall clock time. Is there a way to do this in Java? We are using JDK 1.5.

You can use methods which rely on the nanoTime() (based on the number of clock cycles since the processor last reset)
Classes such as LockSupport.parkUntil(someObject, nanoTime) may give you the accuracy/consistency you want. In this case you always wait the full delay.(and not unpack it)

Menu and Thread.sleep(5000) or Thread.currentThread.sleep(5000)

Hi,
I am using JMenu and switchable JPanels.
When I click on a MenuItem the follownig code should starts
    cards.add(listenPanel, "listenPanel");
    cardLayout.show(cards, "listenPanel");
    try{
      Thread.sleep(5000); //in ms
      PlayMP3Thread sound = new PlayMP3Thread("sound/ping.mp3");
    } catch(Exception e) {
      e.printStackTrace();
    }It seems to be what I want to reach, but it does not work the way I want it to.
I would like the Panel to show right away, then wait 5s and then play the sound.
BUT what it does is freez the unfolded menu for 5s, then plays the sound and after that it shows the new Plane.
Can you tell me why this is??

This might be what you want
package tjacobs.thread;
import java.awt.Dimension;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.concurrent.Semaphore;
import tjacobs.ui.Eyes;
import tjacobs.ui.util.WindowUtilities;
public class ThreadForMultipleAnytimeRuns extends Thread {
     private Runnable mRunnable;
     private Semaphore mSemaphore;
     public ThreadForMultipleAnytimeRuns(Runnable arg0) {
          super();
          init(arg0);
     private void init(Runnable r) {
          mRunnable = r;
          mSemaphore = new Semaphore(0);
          setDaemon(true);
     public ThreadForMultipleAnytimeRuns(Runnable arg0, String arg1) {
          super(arg1);
          init(arg0);
     public ThreadForMultipleAnytimeRuns(ThreadGroup arg0, Runnable arg1, String arg2) {
          super(arg0, arg2);
          init(arg1);
     public void run () {
          try {
               while (!isInterrupted()) {
                    mSemaphore.acquire();
                    mRunnable.run();
          catch (InterruptedException ex) {}
     public void runAgain() {
          mSemaphore.release();
     public void runAgain(int numTimes) {
          mSemaphore.release(numTimes);
     public void stopThread() {
          interrupt();
     public int getSemaphoreCount() {
          return mSemaphore.availablePermits();
     public Runnable getRunnable() {
          return mRunnable;
     //The setRunnable method is simply not safe, and
     //trying to make it safe is going to effect performance
     //Plus I can't really see a gain in being able to set
     //The runnable on one of these threads. Just create
     //a new one!
     public synchronized void setRunnable(Runnable r) {
          if (getSemaphoreCount() > 0) {
               try {
                    wait();
               catch (InterruptedException ex) {
                    return;
          mRunnable = r;
     public static void main(String[] args) {
          final Eyes eyes = new Eyes(true);
          //eyes.addMouseMotionListener(eyes);
          Runnable r = new Runnable() {
               public void run() {
                    eyes.blink();
                    try {
                         Thread.sleep(100);
                    catch(InterruptedException ex) {}
          final ThreadForMultipleAnytimeRuns ar = new ThreadForMultipleAnytimeRuns(r);
          ar.start();
          eyes.addMouseListener(new MouseAdapter() {
               public void mouseClicked(MouseEvent me) {
                    ar.runAgain();
          eyes.setPreferredSize(new Dimension(60,20));
          WindowUtilities.visualize(eyes);
//          JFrame jf = new JFrame();
//          jf.add(eyes);
//          jf.pack();
//          jf.setLocation(100,100);
//          jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//          jf.setVisible(true);
}

Java Thread.sleep(timeout) is influenced by changes to System time on Linux

Java Thread.sleep(timeout) is influenced by changes to System time on Linux
bugId : 6311057
I encountered this problem in redhat6/ jdk 1.6

890651 wrote:
Java Thread.sleep(timeout) is influenced by changes to System time on Linux
bugId : 6311057
I encountered this problem in redhat6/ jdk 1.6At least half the time I use it, I'd want it to be, the other half I wouldn't care.
What are you doing with it where this might be a problem?
Changing the system clock abruptly can cause all kinds of problems with your system anyway, because various background activities etc. often depend on file dates. Wherever possible use the "skew" method to adjust your system clock, rather than just plonking in a new value, especially if you are setting the clock backwards.

What is preventing my Mac from sleeping?

Ever since installing Lion, both of my Mac Pros don't sleep properly.
When the machine wakes, the Mail notification sound, sounds many, many times. EG: If I have receives 100 emails since sleep, it notifies me 100 times.
How can I tell what is preventing my Mac from sleeping, or is this multiple mail sound something else?

There are few threads in this site discussing the same issue.
Causes sited are
File sharing as mentioned in your post,
Recently installed antivirus software,
External HD not properly ejected,
Print Que not cleared
and Mail constantly checking for new mail that you can change in Mail > Preference >General.
Solutions suggested are
Reset PRAM and SMC
and Repair Disk using Recovery HD.
Best.

Whats wrong, why doesnt the thread start?

Below is my code for the part of my program, which creates a thread for every client that connects to a server in an instant messenger program. What the thread does it constantly recieves any data sent to the server, so that it therefore displays it on its own area of the screen. For some reason...this thread does not want to start. Any help would be incredibly appreciated. So heres the code:
class SocketClient extends JFrame implements Runnable {
     Socket socket = null;
   PrintWriter out = null;
   BufferedReader in = null;
          String text = null;
          Thread getdata;
   SocketClient(){
     public void listenSocket() {
     if ( connected==("2") ) {
//Create socket connection
     try{
       socket = new Socket("0.0.0.0", 4444);
                    System.out.println("Connected to self");
       out = new PrintWriter(socket.getOutputStream(), true);
       in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
     } catch (UnknownHostException e) {
       System.out.println("Unknown host: host your connecting to");
       System.exit(1);
     } catch (IOException e) {
       System.out.println("No I/O");
       System.exit(1);
               connected = "1";
     else {
          try{
                socket = new Socket("0.0.0.0", 4444);
       out = new PrintWriter(socket.getOutputStream(), true);
       in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
     } catch (UnknownHostException e) {
       System.out.println("Unknown host: host your connecting to");
       System.exit(1);
     } catch (IOException e) {
       System.out.println("No I/O");
       System.exit(1);
     if (thisclient==(1))
               System.out.println("in thisserver");
               Thread getdata = new Thread();
                         getdata.start();
                         thisclient = 2;
     senddata();
public void senddata() {
     //Send data over socket
     System.out.println("in send data method");
     friendtypingLabel.setText("in send data");
          String text = messageArea.getText();
          out.println(text);
       messageArea.setText(new String(""));
//Receive text from server
public void run()
          if(getdata == Thread.currentThread() )
               System.out.println("running getdata thread"); // if the thread was running this would be written to system but it isnt
               friendtypingLabel.setText("running get data");
               getdatamethod();
public void getdatamethod() {
     //Send data over socket
//Receive text from server
while(true) {
       try{
       String line = in.readLine();
          messlistArea.append("Message Client:" + line + "\n");
       } catch (IOException e){
      System.out.println("Read failed");
             System.exit(1);
          try { Thread.sleep(2000); }
               catch(InterruptedException e) {}
}

k...well ive made it so that the client can see what they have just sent....but i cant seem to make is so that the can see wot the server and wot other clients have sent...here is some update code:
class SocketClient extends JFrame implements Runnable {
     Socket socket = null;
   PrintWriter out = null;
   BufferedReader in = null;
          String text = null;
   SocketClient(){
     public void listenSocket() {
     if ( connected==("2") ) {
//Create socket connection
     try{
       socket = new Socket("0.0.0.0", 4444);
                    System.out.println("Connected to self");
       out = new PrintWriter(socket.getOutputStream(), true);
       in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
     } catch (UnknownHostException e) {
       System.out.println("Unknown host: host your connecting to");
       System.exit(1);
     } catch (IOException e) {
       System.out.println("No I/O");
       System.exit(1);
               connected = "1";
     else {
          try{
                socket = new Socket("0.0.0.0", 4444);
       out = new PrintWriter(socket.getOutputStream(), true);
       in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
     } catch (UnknownHostException e) {
       System.out.println("Unknown host: host your connecting to");
       System.exit(1);
     } catch (IOException e) {
       System.out.println("No I/O");
       System.exit(1);
     if (thisclient==(1))
               System.out.println("in thisserver");
               getdata = new Thread(this);
                                                                                                                                            // if this is the client, then start the getdata
                         getdata.start();                                                                           // thread
                         thisclient = 2;
                         getdata.equals(Thread.currentThread());
     senddata();
public void senddata() {
     //Send data over socket
     System.out.println("in send data method");
     friendtypingLabel.setText("in send data");
          String text = messageArea.getText();
          out.println(text);
       messageArea.setText(new String(""));
//Receive text from server
public void run()                                                   // runs the thread getdata
System.out.println("Thread is " + Thread.currentThread());
          if(getdata.equals(Thread.currentThread()) )
               getdatamethod();
public void getdatamethod() {                      // method for the getdata thread
     //Send data over socket
//Receive text from server
while(true) {
System.out.println("Run getdata");
       try{
                 String line = in.readLine();
                    if (line != null) {
          messlistArea.append("Message Client:" + line + "\n");
                         }catch (IOException e){
                          System.out.println("Read failed");
                  System.exit(1);
          try { Thread.sleep(2000); }
               catch(InterruptedException e) {}
}

How to assgn Thread Sleep time

Hello forum,
I am building a GUI based applcaition but as learnt, it is wiser to seperate the GUI engine from the main data manipuation engine by placing then on seperate Threads which I had fun doing only that I find it difficult knowing what sleep time to give to seperate threads tp optimize the performance of both
Can I ask like, what are the things to be looked at before assigning sleep time to each threads. I dont want GUI to slow down and also engine. And lets say i have like 4 threads running where GUI is one. how do i go about the Thread sleep time assignment.
Thanks You

I think you might want to look at thread priorities. Maybe, something like Thread.yeild() too.

Contiunous running programs: Thread.sleep vs. Scheduled Tasks

Hello,
I have simulation programs that should run continuously for weeks at a time. I am seeking any advice or comments on the best way to do something like this.
Some programs run every 30 seconds; others run once per hour; others run once per day. These programs involve simulating the use of a popular website by reading web pages and inserting records into Oracle 9i databases.
As far as the "every 30 seconds" program, I use Thread.sleep to pause the program for each interval. Is this a good method?
What about programs running once per hour or per day? I have used the Windows XP Scheduled Task program to execute the program. Is this a good method?
Does anybody know of a better way to do such things?
Any comments or helpful links are greatly appreciated.
Thank you,
Logan

I have simulation programs that should run
continuously for weeks at a time. I am seeking any
advice or comments on the best way to do something
like this.If you have a simulator, does it have to simulate time on a one to one basis. Could it not simulate 30 seconds, every 3 seconds and thus not need to run for the full week. If you have to run in real time, what are you simulating.
Some programs run every 30 seconds; others run once
per hour; others run once per day. These programs
involve simulating the use of a popular website by
reading web pages and inserting records into Oracle
9i databases.
As far as the "every 30 seconds" program, I use
Thread.sleep to pause the program for each interval.
Is this a good method?No. Sleep for 30 seconds just means there is atleast 30 seconds delay from the end of the last task to the start of the next task. This could means every 30.1 seconds or even every 33 seconds depending on how long the task takes to run.
If you create a single ScheduledExecutorService you can run a task with any period you suggest with a dynamic number of threads.
e.g.
Execuotrs.newScheduledThreadPool(1);
>
What about programs running once per hour or per day?See previous.
I have used the Windows XP Scheduled Task program to
execute the program. Is this a good method?If it is a couple of times per day or per week this is a good choice.
>
Does anybody know of a better way to do such things?see previous.

What is an alternate to Thread.Sleep()?

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