PROBLEMS WITH A THREAD!!!

Hi, guys!
Posted this in another forum, but no good answers...
I got a class "GUI" which is calling a method in class FileCopy on a button-click.
Class GUI calls -------> copy in class FileCopy
The FileCopy-class looks kinda like this:
public class FileCopy implements Runnable {
Thread thread = null;
public void copy( ...params...) {
thread = new Thread(this);
// Asign some vars
thread.start();
private void copyFiles(File file, File destination) {
// Copy the file
public void run() {
for (Iteration e = collection.iterator(); e.hasNext();)
copyFile((File) e.next(), destination);
// Kill thread next
The problem is that the thread seems to call the metod copyFiles and then (before the copyFiles-method is done) go to the part in run where I kill the thread. That results in a non-copied file!!!!
I've tried to use the join-method to get the thread to wait for the copyFiles-method to complete, but then the GUI freezes and that's not an option!!!
Plz help!!!
/Andrew

Hi
you are already in the event thread (dispatching thread)
and you don't need to spawn another thread, just handle the event normally
in your event handler.
if you really want to use thread use a Timer to copy (set a low interval)
or
class FileCopy implements Runnable {
FileCopy(params...) {
// Set your file names and params here
private void copyFiles(File file, File destination) {
// Copy the file
public void run() {
for (Iteration e = collection.iterator(); e.hasNext();) {
copyFile((File) e.next(), destination);
// let the thread end normally
// event handler
public void actionPerformed(ActionEvent e) {
Filecopy copy = new FileCopy(params...);
new Thread(copy).start();
I hope this helps

Similar Messages

  • Problems with a thread that records dvd on suse linux

    PLEASE HELP
    I am using SuSE linux, and I record dvd+/- RW with the program growisofs.
    By command line on the linux shell, growisofs records normally, but when I try to use the same line cone that I use in the shell in a java thread, it never stops recording, I mean, it records all data, but it apparently does not close the dvd session, for the grenn light on the drive never stops blinking, and I have to stop the proccess manually, because it never releases the dvd drive.
    I use the thread in a large program, but for debugging this I have made a simple program, whose error is the same.
    the code is:
            String s = "/usr/local/bin/growisofs -speed=1 -M /dev/dvdram  -V MIS27 -A growisofs -P MedImServer " +
               " -p MedImServer -sysid Linux -J -R -l -relaxed-filenames -allow-lowercase -allow-multidot  /windows/C/online";
           Process p;
                try {
                    p = Runtime.getRuntime().exec(s);
                    p.waitFor();
                catch (IOException ex) {
                    JOptionPane.showMessageDialog(null,"erro no runtime");
                    System.exit(0);
                catch (InterruptedException ex1) {
                    JOptionPane.showMessageDialog(null,"erro no waitfor");
                    System.exit(0);
                }with JBuilder 9 debug, I realized that it freezes at the moment of "p.waitFor()".
    I thought that it was a problem with the recording software, but it is not: the same command line that I use in the program I have used in the Linux shell and it recorded perfectly. The program does not require any user interaction but the command line I wrote before. The problem with the Java program is that it records all data, but never returns from the process. It's not a problem with the software, for it records perfectly when it's not called within the Java program, so I imagine that it is some funny thing in either the Runtime.getRuntime().exec(...) or the p.wait().
    Better yet:
    Is there a way to record dvds with a java command instead with an exteranal program?
    This would be the heaven...
    IF it is possible, do it require some sun package?
    Thans
    Tiago

    Did you mean like this?
            Process p = null;
            String s = null;
            File f;
            try {
                f = new File(pathtmp);
                f.mkdir();
                if(VERBOSE) Log.info(GRAVA_LOG_MARK + "Pasta " + f.getPath() + " criada");
                for (Iterator iter = estudos.iterator(); iter.hasNext(); ) {
                    HashMap item = (HashMap) iter.next();
                    String id = (String) item.get("id_paciente");
                    String dt_hr = (String) item.get("dt_hr_estudo");
                    String estudo = id + "." + dt_hr;
                    File dir = new File(distriOff.path);
                    String[] arquivos = dir.list(new FiltroInicio(estudo));
                    for (int i = 0; i < arquivos.length; i++) {
                        File src = new File(distriOff.path + arquivos);
    File dest = new File(pathtmp + arquivos[i]);
    try {
    Util.copy(src, dest);
    catch (Throwable ex) {
    Log.error(mensagem + " " + ex);
    prop.enviaMsg(mensagem + " " + ex);
    throw new ExcecaoDistribuicao(ExcecaoDistribuicao.ERRO, mensagem + " " + ex);
    String os = System.getProperty("os.name");
    String modo;
    if(midia.getEspaco_disponivel_midia() == midia.getTamanho_midia()) {
    //primeira gravagco
    modo = "-Z";
    else {
    //gravagco de novas segues
    modo = "-M";
    String speed = "-speed=1";
    String cmd = "/usr/local/bin/growisofs " + speed + " " + modo + " " + dvdDevice + " "
    +" -V " + prop.getIdMidiaAtual() + " -A growisofs -P MedImServer "
    +"-p MedImServer -sysid " + os + " -J -R -l -relaxed-filenames -allow-lowercase -allow-multidot " + pathtmp;
    p = Runtime.getRuntime().exec(cmd);
    p.waitFor();
    catch (IOException ex){
    Log.error(mensagem + " " + ex);
    prop.enviaMsg(mensagem + " " + ex);
    throw new ExcecaoDistribuicao(ExcecaoDistribuicao.ERRO, mensagem + " " + ex);
    catch (InterruptedException ex) {
    Log.error(mensagem + " " + ex);
    prop.enviaMsg(mensagem + " " + ex);
    throw new ExcecaoDistribuicao(ExcecaoDistribuicao.ERRO, mensagem + " " + ex);
    try
    BufferedReader stdInput = new BufferedReader(new InputStreamReader(p.getInputStream()));
    // Lj saida padrco do comando
    while ( (s = stdInput.readLine()) != null)
    Log.info(GRAVA_LOG_MARK + s);
    catch (IOException ex)
    Log.error(mensagem + " " + ex);
    prop.enviaMsg(mensagem + " " + ex);
    throw new ExcecaoDistribuicao(ExcecaoDistribuicao.ERRO, mensagem + " " + ex);
    try
    BufferedReader stdErr = new BufferedReader(new InputStreamReader(p.getErrorStream()));
    // Lj qualquer erro do comando
    while ( (s = stdErr.readLine()) != null) {
    Log.info("Processo de Gravagco: " + s);
    if((s.indexOf("failed") != -1) || (s.indexOf("error") != -1) || (s.indexOf("unable") != -1)) {
    Log.error(mensagem + " " + s);
    prop.enviaMsg(mensagem + " " + s);
    throw new ExcecaoDistribuicao(ExcecaoDistribuicao.ERRO, mensagem + " " + s);
    catch (IOException ex)
    Log.error(mensagem + " " + ex);
    prop.enviaMsg(mensagem + " " + ex);
    throw new ExcecaoDistribuicao(ExcecaoDistribuicao.ERRO, mensagem + " " + ex);
    I tried to execute it, and it indeed doesn't freeze, but it doesn't record a thing either...
    now it doesn't even wait for the thread, which is VERY weird: it does not record a thing!!! It just passes by the line 'p.waitFor()'...
    Any sugestion?
    By the way, thanks for helping me...
    Tiago

  • I have problems with seeing thread posts...

    I got problems with this Forum itself: I can't see the posts of the threads. Just a few times I did see the content of one page but if I will go to the next page, the posts are be hidden again =/

    I was having the same problem.  Emptying the Safari caches and restarting has fixed it - at least for now.

  • Problem with painting/threads/ProgressMonitor

    Hello,
    I'll try to be clear, ask me anything if it isn't. I have two threads, one that downloads some selected webpages, and the other that reads them. In the thread that reads, there is a ProgressMonitor object, which indicate how many webpages have been read.
    I created a JUnit test which works as expected. One thread downloads, the other reads and a nice little progress monitor appears and everything works.
    I transfered the code (the part of the code starting the thread that reads, which starts the thread that downloads) into the main application. The threads are working and the ProgressMonitor appears, but it does not draw the components (there is no label, progress bar, button etc...). I can't seem to find the problem. I think it is caused by the threads or synchronized methods, I am not sure as I am no expert with threads. Once the threads have finished running, the components of the ProgressMonitor appears. So I guess that the threads are blocking the (re)painting of the application, but I can't figure why. Im using Thread.yield() quite often. Priorities problem ? Here some parts of the code :
    JUnit Test code :
         public synchronized void testHarvest() {
              JFrame frame = new JFrame("Super");
              frame.setVisible(true);
              Harvester harvester = new Harvester(
                        frame,
                        new Rule());
              Thread harvest = new Thread(harvester);
              harvest.start();
              try {
                   harvest.join();
              } catch (InterruptedException ie) {}
    ...Main application :
    Code:
    public class Gui extends JFrame implements ComponentListener {
       private static JFrame mMotherFrame = null;
        public Gui() {
            mMotherFrame = this;
        private class GuiActionRealize {
              public synchronized void getFromWeb() {
                   Harvester harvester = new Harvester(
                             mMotherFrame,
                             new Rule());
                   Thread harvest = new Thread(harvester);
                   harvest.start();               
                   try {                    
                        harvest.join();
                   } catch (InterruptedException ie) {}
    }Harvester :
    Code:
    public class Harvester implements Runnable {
      private JFrame mMotherFrame;
      private ProgressMonitor mMonitor;
    public Harvester(JFrame owner, IRule subjectRule) {
       mMotherFrame = owner;
        public void find() {
        mMonitor = new ProgressMonitor(mMotherFrame, "Downloading from the Internet.", "", 1, mAcceptedURLs.size());
         mMonitor.setMillisToDecideToPopup(0);
         mMonitor.setMillisToPopup(0);
    public void run() {
      find();
      mHarvested = harvest();
      mFinished = true;
      Thread.yield();
    public List harvest() {
      download = new DownloadThread(this, mAcceptedURLs);
      Thread downthread = new Thread(download);
      downthread.start(); int i = 0;
      while (!mMonitor.isCanceled()) {
          while (download.getDownloadedDocuments().isEmpty()) {
               try {
                       Thread.yield();
                       Thread.sleep(300);
                } catch (InterruptedException ie) {}
           mMonitor.setNote("Downloading decision " + i);
           mMonitor.setProgress(mMonitor.getMinimum()+ ++i);
           } // end while(!cancel)
           download.kill();
           return mHarvested;
    }I'm very puzzled by the fact that it worked in the JUnit Case and not in the application.
    I can see that the thread that is responsible for drawing components is not doing his job, since that the mother frame (Gui class) is not being repainted while the harvest/download threads are working. That's not the case in the JUnit case, where the frame is being repainted and everything is fine. This is the only place in the application that I'm using threads/runnable objects.
    I also tried making the Gui class a thread by implementing the Runnable interface, and creating the run method with only a repaint() statement.
    And I tried setting the priority of the harvest thread to the minimum. No luck.
    If you need more info/code, let me know, Ill try to give as much info as I can.
    Thank you

    Why are you painting the values yourself? Why don't you just add the selected values to a JList, or create a container with a GridLayout and add a JLabel with the new text to the container.
    Every time you call the paintComponent() method the painting gets done from scratch so you would need to keep a List of selected items and repaint each item every time. Maybe this [url http://forum.java.sun.com/thread.jsp?forum=57&thread=304939]example will give you ideas.

  • Problem with multiple threads accessing the same Image

    I'm trying to draw into one Image from multiple threads. It works fine for a while, but then suddenly, the image stops updating. Threads are still running but the image won't update. I'm using doublebuffering and threads are simply drawing counters into Image with different speed.
    It seems like the Image gets deadlocked or something. Anyone have any idea what's behind this behavior or perhaps better solution to do such thing.
    Any help will be appreciated.

    Sorry Kglad, I didn't mean to be rude. With "No coding
    errors" I meant the animation itself runs with no errors. I'm sure
    you could run the 20 instances with no freezing (that's why I put
    the post :) ) But I'm affraid it is an animation for a client, so I
    cannot distribute the code.
    Perhaps I didnt explain the situation clearly enough (in part
    because of my poor english...).-
    - By 20 instances I mean 20 separated embedded objects in the
    html
    - The animation is relatively simple. A turned on candle, in
    each cycle I calculate the next position of the flame (that
    oscilates from left to right). The flame is composed by 4
    concentric gradients. There is NO loops, only an 'onEnterFrame'
    function refreshing the flame each time.
    - It's true that I got plenty variables at the _root level.
    If that could be the problem, how can I workaround it?
    - It is my first time trying to embed so many objects at the
    same time too. No idea if the problem could be the way I embed the
    object from the html :(
    - The only thing I can guess is that when a cycle of one of
    the object is running, the other 19 objects must wait their turn.
    That would explain why the more instances I run, the worst results
    I get. In that case, I wonder if there's a way to run them in a
    kind of asynchronous mode, just guessing...
    Any other comment would be appreciated. Anyway, thanks a lot
    everybody for your colaboration.

  • Problems with java Thread

    I'm reading book "JAVA THREAD" published by OREILLY.
    And on fifth chapter, it gives an example.
    one Thread's two method:
    private boolean done = false;
    public void run()
    while(!done)
    foo();
    public void setDone()
    done = true;
    it says, the run method will be compiled as machine code:
    Begin method run
    load register r1 with memory location 0xff12345
    Label L1:
    Test if register r1 == 1
    If true branch to L2
    Call method foo
    Branch to L1
    Label L2:
    End method run
    setDone method will be compiled like:
    Begin method setDone
    Store 1 into memory location 0xff12345
    End method setDone
    And it says " because Run method will never reload 0xff12345 to register r1(in while loop), so setDone method will never lead to run stop.
    I'm so puzzled with this. I have test this code on windows platform, run method can stop after another Thread call setDone method !.
    but I think "JAVA THREAD" should have error on this, so why ?

    If the book says it will happen like that, then the book is wrong.
    I think what they meant--and what would be correct to say--is that that is an example of what could happen if you don't synchronize all access to the run variable.
    The point is this: Threads can have local copies of variables, that are separate from other threads' local copies and separate from the "master" copy. The spec doesn't define where those local copies live--the implementation can put them anywhere it wants--but the most natural and sensible thing would be to store the local copies in CPU registers, rather than in main mem.
    The example the book gave shows what might happen if that VM stores threads' local copies in registers. There's no guarantee that the problem they described will happen, but it could, so you have to guard against it.
    You guard against it by declaring that shared variable volatile, which requires that the threads use the master copy rather than their local copies, or by synchronizing every access to that thread. Syncing requires reading from the master copy on entering the sync block (or on first access) and writing out to the master copy upon leaving the sync block.

  • Problem with Java threads

    Hi,
    I developed a class, which reads some data from an XML file and transports it to a database, using JDBC. The class worked perfectly fine.Then, I used a thread to execute the same class (using the run() method and the usual stuff), but now as soon as the thread exits, Windows says that an illegal memory access has been made.
    Has anybody encountered a similar problem? any help will be appreciated.
    thanx,
    regards.

    What type of driver are you using? If it's the JDBC ODBC bridge or any other driver that uses native libraries then maybe improper resource deallocation could cause the trouble.
    robert

  • Problem with my Thread

    MainProgram
    Thread1->named th does some process
    Thread2->ProgressBar where i have this code
    while(th.isAlive())
    Thread.sleep(4000);
    My program is stuck up in the above loop. Eventhough thread1 and thread2 are independent,thread one is never dead. Once thread2 completes its task thread1 is getting dead. Why this happens.
    In short i want both thread to be executed parallely

    perhaps you should first test your ideas on simple code before implementing them in a real program? So just generate some test code like this:
    public class Test {
         public static void main(String[] args) {
              Thread thread1 = new Thread1();
              Thread thread2 = new Thread2(thread1);
              thread1.start();
              thread2.start();
    class Thread1 extends Thread {
         public void run() {
              System.out.println("Thread 1 started.");
              int count = 3;
              while (count > 0) {
                   System.out.println("Thread 1 goes to sleep.");
                   try {
                        Thread.sleep(2500);
                   } catch (InterruptedException e) {}
                   System.out.println("Thread 1 wakes up.");
                   count--;
              System.out.println("Thread 1 ended.");
    class Thread2 extends Thread {
         Thread watchedThread;
         Thread2(Thread aThread) {
              this.watchedThread = aThread;
         public void run() {
              System.out.println("Thread 2 started.");
              while (this.watchedThread.isAlive()) {
                   System.out.println("Thread 2 goes to sleep.");
                   try {
                        Thread.sleep(1000);
                   } catch (InterruptedException e) {}
                   System.out.println("Thread 2 wakes up.");
              System.out.println("Thread 2 ended.");
    }When you have figured out what you want (and how to do it), only then implement it in a real program.

  • Problems with 'My Threads'

    Hi everybody,
    I understand that it's hard to please everybody, but after the switch back to all threads I started to get Internal Server Error and very slow performance when the list works.
    Is it possible to have an option of how many threads to show (or date filter)? The date filter can default to last 2 months, but it could be changed by a user. Also, default date filter can be configured in the settings.
    For every expert, there is an equal and opposite expert. - Becker's Law
    My blog
    My TechNet articles

    I submitted this as a bug request. Thanks!
    Ed Price, Power BI & SQL Server Customer Program Manager (Blog,
    Small Basic,
    Wiki Ninjas,
    Wiki)
    Answer an interesting question?
    Create a wiki article about it!

  • Problem with threads running javaw

    Hi,
    Having a problem with multi thread programming using client server sockets. The program works find when starting the the application in a console using java muti.java , but when using javaw multi.java the program doesnt die and have to kill it in the task manager. The program doesnt display any of my gui error messages either when the server disconnect the client. all works find in a console. any advice on this as I havent been able to understand why this is happening? any comment would be appreciated.
    troy.

    troy,
    Try and post a minimum code sample of your app which
    does not work.
    When using javaw, make sure you redirect the standard
    error and standard output streams to file.
    Graeme.Hi Graeme,
    I dont understand what you mean by redirection to file? some of my code below.
    The code works fine under a console, code is supposed to exit when the client (the other server )disconnects. the problem is that but the clientworker side of the code still works. which under console it doesnt.
    public class Server{
    ServerSocket aServerSocket;
    Socket dianosticsSocket;
    Socket nPortExpress;
    ClientListener aClientListener;
    LinkedList queue = new LinkedList();
    int port = 0;
    int clientPort = 0;
    String clientName = null;
    boolean serverAlive = true;
    * Server constructor generates a server
    * Socket and then starts a client threads.
    * @param aPort      socket port of local machine.
    public Server(int aPort, String aClientName, int aClientPort){
    port = aPort;
    clientName = aClientName;
    clientPort = aClientPort;
    try{
    // create a new thread
    aServerSocket = new ServerSocket(port) ;
    // connect to the nPortExpress
    aClientListener = new ClientListener(InetAddress.getByName(clientName), clientPort, queue,this);
    // aClientListener.setDaemon(true);
    aClientListener.start();
    // start a dianostic port
    DiagnosticsServer aDiagnosticsServer = new DiagnosticsServer(port,queue,aClientListener);
    // System.out.println("Server is running on port " + port + "...");
    // System.out.println("Connect to nPort");
    catch(Exception e)
    // System.out.println("ERROR: Server port " + port + " not available");
    JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Server port " + port + " not available", JOptionPane.ERROR_MESSAGE);
    serverAlive = false;
    System.exit(1);
    while(serverAlive&&aClientListener.hostSocket.isConnected()){
    try{
    // connect the client
    Socket aClient = aServerSocket.accept();
    //System.out.println("open client connection");
    //System.out.println("client local: "+ aClient.getLocalAddress().toString());
    // System.out.println("client localport: "+ aClient.getLocalPort());
    // System.out.println("client : "+ aClient.getInetAddress().toString());
    // System.out.println("client port: "+ aClient.getLocalPort());
    // make a new client thread
    ClientWorker clientThread = new ClientWorker(aClient, queue, aClientListener, false);
    // start thread
    clientThread.start();
    catch(Exception e)
    //System.out.println("ERROR: Client connection failure");
    JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Client connection failure", JOptionPane.ERROR_MESSAGE);
    }// end while
    } // end constructor Server
    void serverExit(){
         JOptionPane.showMessageDialog(null, "Server ","ERROR: nPort Failure", JOptionPane.ERROR_MESSAGE);
         System.exit(1);
    }// end class Server
    *** connect to another server
    public class ClientListener extends Thread{
    InetAddress hostName;
    int hostPort;
    Socket hostSocket;
    BufferedReader in;
    PrintWriter out;
    boolean loggedIn;
    LinkedList queue;      // reference to Server queue
    Server serverRef; // reference to main server
    * ClientListener connects to the host server.
    * @param aHostName is the name of the host eg server name or IP address.
    * @param aHostPort is a port number of the host.
    * @param aLoginName is the users login name.
    public ClientListener(InetAddress aHostName, int aHostPort,LinkedList aQueue,Server aServer)      // reference to Server queue)
    hostName = aHostName;
    hostPort = aHostPort;
    queue = aQueue;
    serverRef = aServer;      
    // connect to the server
    try{
    hostSocket = new Socket(hostName, hostPort);
    catch(IOException e){
    //System.out.println("ERROR: Connection Host Failed");
    JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Connection to nPort Failed", JOptionPane.ERROR_MESSAGE);     
    System.exit(0);
    } // end constructor ClientListener
    ** multi client connection server
    ClientWorker(Socket aSocket,LinkedList aQueue, ClientListener aClientListener, boolean diagnostics){
    queue = aQueue;
    addToQueue(this);
    client = aSocket;
    clientRef = aClientListener;
    aDiagnostic = diagnostics;
    } // end constructor ClientWorker
    * run method is the main loop of the server program
    * in change of handle new client connection as well
    * as handle all messages and errors.
    public void run(){
    boolean alive = true;
    String aSubString = "";
    in = null;
    out = null;
    loginName = "";
    loggedIn = false;
    while (alive && client.isConnected()&& clientRef.hostSocket.isConnected()){
    try{
    in = new BufferedReader(new InputStreamReader(client.getInputStream()));
    out = new PrintWriter(new OutputStreamWriter(client.getOutputStream()));
    if(aDiagnostic){
    out.println("WELCOME to diagnostics");
    broadCastDia("Connect : diagnostics "+client.getInetAddress().toString());
    out.flush();
    else {       
    out.println("WELCOME to Troy's Server");
    broadCastDia("Connect : client "+client.getInetAddress().toString());
         out.flush();
    String line;
    while(((line = in.readLine())!= null)){
    StringTokenizer aStringToken = new StringTokenizer(line, " ");
    if(!aDiagnostic){
    broadCastDia(line);
    clientRef.sendMessage(line); // send mesage out to netExpress
    out.println(line);
    out.flush();
    else{
    if(line.equals("GETIPS"))
    getIPs();
    else{
    clientRef.sendMessage(line); // send mesage out to netExpress
    out.println(line);
    out.flush();
    } // end while
    catch(Exception e){
    // System.out.println("ERROR:Client Connection reset");
                             JOptionPane.showMessageDialog(null, (e.toString()),"ERROR:Client Connection reset", JOptionPane.ERROR_MESSAGE);     
    try{
    if(aDiagnostic){
    broadCastDia("Disconnect : diagnostics "+client.getInetAddress().toString());
    out.flush();
    else {       
    broadCastDia("Disconnect : client "+client.getInetAddress().toString());
         out.flush();
    // close the buffers and connection;
    in.close();
    out.close();
    client.close();
    // System.out.println("out");
    // remove from list
    removeThreadQueue(this);
    alive = false;
    catch(Exception e){
    // System.out.println("ERROR: Client Connection reset failure");
    JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Client Connection reset failure", JOptionPane.ERROR_MESSAGE);     
    }// end while
    } // end method run
    * method run - Generates io stream for communicating with the server and
    * starts the client gui. Run also parses the input commands from the server.
    public void run(){
    boolean alive = true;
    try{
    // begin to life the gui
    // aGuiClient = new ClientGui(hostName.getHostName(), hostPort, loginName, this);
    // aGuiClient.show();
    in = new BufferedReader(new InputStreamReader(hostSocket.getInputStream()));
    out = new PrintWriter(new OutputStreamWriter(hostSocket.getOutputStream()));
    while (alive && hostSocket.isConnected()){
    String line;
    while(((line = in.readLine())!= null)){
    System.out.println(line);
    broadCast(line);
    } // end while
    } // end while
    catch(Exception e){
    //     System.out.println("ERRORa Connection to host reset");
    JOptionPane.showMessageDialog(null, (e.toString()),"ERROR: Connection to nPort reset", JOptionPane.ERROR_MESSAGE);
    try{
    hostSocket.close();
         }catch(Exception a){
         JOptionPane.showMessageDialog(null, (a.toString()),"ERROR: Exception", JOptionPane.ERROR_MESSAGE);
    alive = false;
    System.exit(1);
    } // end method run

  • Problem with threads and ProgressMonitor

    Dear Friends:
    I have a little problem with a thread and a ProgressMonitor. I have a long time process that runs in a thread (the thread is in an separate class). The thread has a ProgressMonitor that works fine and shows the tasks progress.
    But I need deactivate the main class(the main class is the user interface) until the thread ends.
    I use something like this:
    LongTask myTask=new LongTask();
    myTask.start();
    myTask.join();
    Now, the main class waits for the task to end, but the progress monitor don`t works fine: it shows only the dialog but not the progress bar.
    What's wrong?

    Is the dialog a modal dialog? This can block other UI updates.
    In general, you should make sure that it isn't modal, and that your workThread has a fairly low priority so that the UI can do its updating

  • A problem with threads

    I am trying to implement some kind of a server listening for requests. The listener part of the app, is a daemon thread that listens for connections and instantiates a handling daemon thread once it gets some. However, my problem is that i must be able to kill the listening thread at the user's will (say via a sto button). I have done this via the Sun's proposed way, by testing a boolean flag in the loop, which is set to false when i wish to kill the thread. The problem with this thing is the following...
    Once the thread starts excecuting, it will test the flag, find it true and enter the loop. At some point it will LOCK on the server socket waiting for connection. Unless some client actually connects, it will keep on listening indefinatelly whithought ever bothering to check for the flag again (no matter how many times you set the damn thing to false).
    My question is this: Is there any real, non-theoretical, applied way to stop thread in java safely?
    Thank you in advance,
    Lefty

    This was one solution from the socket programming forum, have you tried this??
    public Thread MyThread extends Thread{
         boolean active = true;          
         public void run(){
              ss.setSoTimeout(90);               
              while (active){                   
                   try{                       
                        serverSocket = ss.accept();
                   catch (SocketTimeoutException ste){
                   // do nothing                   
         // interrupt thread           
         public void deactivate(){               
              active = false;
              // you gotta sleep for a time longer than the               
              // accept() timeout to make sure that timeout is finished.               
              try{
                   sleep(91);               
              }catch (InterruptedException ie){            
              interrupt();
    }

  • Problem with Threads and a static variable

    I have a problem with the code below. I am yet to make sure that I understand the problem. Correct me if I am wrong please.
    Code functionality:
    A timer calls SetState every second. It sets the state and sets boolean variable "changed" to true. Then notifies a main process thread to check if the state changed to send a message.
    The problem as far I understand is:
    Assume the timer Thread calls SetState twice before the main process Thread runs. As a result, "changed" is set to true twice. However, since the main process is blocked twice during the two calls to SetState, when it runs it would have the two SetState timer threads blocked on its synchronized body. It will pass the first one, send the message and set "changed" to false since it was true. Now, it will pass the second thread, but here is the problem, "changed" is already set to false. As a result, it won't send the message even though it is supposed to.
    Would you please let me know if my understanding is correct? If so, what would you propose to resolve the problem? Should I call wait some other or should I notify in a different way?
    Thanks,
    B.D.
    Code:
    private static volatile boolean bChanged = false;
    private static Thread objMainProcess;
       protected static void Init(){
            objMainProcess = new Thread() {
                public void run() {
                    while( objMainProcess == Thread.currentThread() ) {
                       GetState();
            objMainProcess.setDaemon( true );
            objMainProcess.start();
        public static void initStatusTimer(){
            if(objTimer == null)
                 objTimer = new javax.swing.Timer( 1000, new java.awt.event.ActionListener(){
                    public void actionPerformed( java.awt.event.ActionEvent evt){
                              SetState();
        private static void SetState(){
            if( objMainProcess == null ) return;
            synchronized( objMainProcess ) {
                bChanged = true;
                try{
                    objMainProcess.notify();
                }catch( IllegalMonitorStateException e ) {}
        private static boolean GetState() {
            if( objMainProcess == null ) return false;
            synchronized( objMainProcess ) {
                if( bChanged) {
                    SendMessage();
                    bChanged = false;
                    return true;
                try {
                    objMainProcess.wait();
                }catch( InterruptedException e ) {}
                return false;
        }

    Thanks DrClap for your reply. Everything you said is right. It is not easy to make them alternate since SetState() could be called from different places where the state could be anything else but a status message. Like a GREETING message for example. It is a handshaking message but not a status message.
    Again as you said, There is a reason I can't call sendMessage() inside setState().
    The only way I was able to do it is by having a counter of the number of notifies that have been called. Every time notify() is called a counter is incremented. Now instead of just checking if "changed" flag is true, I also check if notify counter is greater than zero. If both true, I send the message. If "changed" flag is false, I check again if the notify counter is greater than zero, I send the message. This way it works, but it is kind of a patch than a good design fix. I am yet to find a good solution.
    Thanks,
    B.D.

  • Problem with threads and camera.

    Hi everybody!
    I've a problem with taking snapshot.
    I would like to display a loading screen after it take snapshot ( sometimes i
    have to wait few seconds after i took snapshot. Propably photo is being taken in time where i have to wait).
    I was trying to use threads but i didn't succeed.
    I made this code:
    display.setCurrent(perform);               
            new Thread(new Runnable(){
                public void run() {               
                    while((!performing.isShown()) && (backgroundCamera.isShown())){
                        Thread.yield();
                    notifyAll();
            }).start();
            new Thread(new Runnable(){
                public void run() {
                    try {
                        this.wait();                   
                    } catch(Exception e) {
                        exceptionHandler(e);
                    photo = camera.snapshot();                               
                    display.setCurrent(displayPhoto);
            }).start();This code is sometimes showing performing screen but sometimes no.
    I don't know why. In my opinion performing.isShown() method isn't working correctly.
    Does anyone have some idea how to use threads here?

    Hi,
    I've finally managed to work this fine.
    The code:
           Object o = new Object();
           display.setCurrent(perform);               
            new Thread(new Runnable(){
                public void run() {               
                    while(!performing.isShown()){
                        Thread.yield();
                   synchronized(o) {
                      o.notify();
            }).start();
            new Thread(new Runnable(){
                public void run() {
                    try {
                        synchronized(o) {
                           o.wait(1);
                    } catch(Exception e) {
                        exceptionHandler(e);
                    photo = camera.snapshot();                               
                    display.setCurrent(displayPhoto);
            }).start();

  • Problem with threads hanging

    We have a problem where our application stops responding after a few days of usage. Things will for fine for a day or two, and then pretty quickly threads will start getting hung up, usually in places where they are allocating memory
    We are running WebLogic 8.1 SP2 on Sun JDK 1.4.2_04 on Solaris 8 using the alternate threading model and the -server hotspot vm. We are running pretty much the same code that we had no problems with under WebLogic 6.1 SP4 and Sun JDK 1.3.1.
    A thread dump usually shows that some or all of our execute threads are in the state "waiting for monitor entry" even though they are not currently waiting on any java locks. Here is a sample thread from the thread dump (we have ~120 threads so I don't want to post the full dump).
    =============================================================================================
    "ExecuteThread: '8' for queue: 'itgCrmWarExecutionQueue'" daemon prio=5 tid=0x005941d0 nid=0x2c waiting for monitor entry [c807f000..c807fc28]
    at java.lang.String.substring(String.java:1446)
    at java.lang.String.substring(String.java:1411)
    at weblogic.servlet.internal.ServletRequestImpl.getRelativeUri(ServletRequestImpl.java:1872)
    at weblogic.servlet.internal.WebAppServletContext.invokeServlet(WebAppServletContext.java:3492)
    at weblogic.servlet.internal.ServletRequestImpl.execute(ServletRequestImpl.java:2585)
    at weblogic.kernel.ExecuteThread.execute(ExecuteThread.java:197)
    at weblogic.kernel.ExecuteThread.run(ExecuteThread.java:170)
    =============================================================================================
    String.java line 1446 for this jdk allocates a new String object, and all the other threads in this state also are creating new objects or arrays, etc.
    We've done a pstack on this process when it's in this state, and the threads that are in the "waiting for monitor entry" that look like they're allocating memory are all waiting on the same lwp_mutex_lock with some allocation method that's calling into the native TwoGenerationCollectorPolicy.mem_allocate_work (see pstack output below for the same thread as in the thread dump above)
    =============================================================================================
    ----------------- lwp# 44 / thread# 44 --------------------
    ff31f364 lwp_mutex_lock (e3d70)
    fee92384 __1cNObjectMonitorGenter26MpnGThread__v_ (5000, 525c, 5000, 50dc, 4800, 4af0) + 2d8
    fee324d4 __1cSObjectSynchronizerKfast_enter6FnGHandle_pnJBasicLock_pnGThread__v_ (c807f65c, c807f7d4, 5941d0, 0, 35d654, fee328ec) + 68
    fee32954 __1cQinstanceRefKlassZacquire_pending_list_lock6FpnJBasicLock__v_ (c807f7d4, ff170000, d4680000, 4491d4, fee1bc2c,
    0) + 78
    fee3167c __1cPVM_GC_OperationNdoit_prologue6M_i_ (c807f7bc, 4400, ff170000, 2d2b8, 4a6268, c807fa18) + 38
    fee2e0b0 __1cIVMThreadHexecute6FpnMVM_Operation__v_ (c807f7bc, 963a8, 0, 0, 1, 0) + 90
    fed2c2a4 __1cbCTwoGenerationCollectorPolicyRmem_allocate_work6MIii_pnIHeapWord__ (962c0, ff1c29ec, ff1c297c, ff131a26, 4800, 4998) + 160
    fed22940 __1cNinstanceKlassRallocate_instance6MpnGThread__pnPinstanceOopDesc__ (ee009020, 5941d0, 15ca581, 3647f0, 4a6268, c807f8c8) + 180
    fed34928 __1cLOptoRuntimeFnew_C6FpnMklassOopDesc_pnKJavaThread__v_ (ee009018, 5941d0, 0, 0, 0, 0) + 28
    fa435a58 ???????? (ee009018, e86de, 15ca4de, 50dc, 5941d0, c807f9c8)
    fb36f9a4 ???????? (0, d412ccd8, ee046c28, ff170000, 0, 0)
    fad8b278 ???????? (ee046c28, d6000c90, ee046530, 8, db8e8450, c807f9e8)
    fad62abc ???????? (d412ccd8, ee046530, d6000c90, ee3bfa38, 8, c807fa18)
    fa4b3c38 ???????? (c807fb9c, 0, f2134700, fa415e50, 8, c807faa8)
    fa40010c ???????? (c807fc28, c807fe90, a, ee9e1e20, 4, c807fb40)
    fed5d48c __1cJJavaCallsLcall_helper6FpnJJavaValue_pnMmethodHandle_pnRJavaCallArguments_pnGThread__v_ (c807fe88, c807fcf0, c807fda8, 5941d0, 5941d0, c807fd00) + 27c
    fee4b784 __1cJJavaCallsMcall_virtual6FpnJJavaValue_nLKlassHandle_nMsymbolHandle_4pnRJavaCallArguments_pnGThread__v_ (ff170000, 594778, c807fd9c, c807fd98, c807fda8, 5941d0) + 164
    fee5e8dc __1cJJavaCallsMcall_virtual6FpnJJavaValue_nGHandle_nLKlassHandle_nMsymbolHandle_5pnGThread__v_ (c807fe88, c807fe84, c807fe7c, c807fe74, c807fe6c, 5941d0) + 6c
    fee6fc74 __1cMthread_entry6FpnKJavaThread_pnGThread__v_ (5941d0, 5941d0, 838588, 594778, 306d10, fee69254) + 128
    fee6927c __1cKJavaThreadDrun6M_v_ (5941d0, 2c, 40, 0, 40, 0) + 284
    fee6575c _start   (5941d0, fa1a1600, 0, 0, 0, 0) + 134
    ff3758c0 lwpstart (0, 0, 0, 0, 0, 0)
    =============================================================================================
    Also when it's having this problem, the "VM Thread" is always using a lot of processor time. We did a couple of pstacks today while it was having this problem, and this thread was stuck in the ONMethodSweeper.sweep for over 15 minutes when we finally killed the server.
    From the thread dump:
    "VM Thread" prio=5 tid=0x000e2d20 nid=0x2 runnable
    From the first pstack:
    =============================================================================================
    ----------------- lwp# 2 / thread# 2 --------------------
    fed40c04 __1cXvirtual_call_RelocationIparse_ic6FrpnICodeBlob_rpC5rppnHoopDesc_pi_nNRelocIterator__ (42a2f4, fa5fa46d, ffffffff, fc4ffcb8, 42a2f4, 42a324) + 124
    fed46318 __1cKCompiledIC2t5B6MpnKRelocation__v_ (42a2f0, fc4ffd24, fc4ffd4c, e802, 0, 6) + 38
    fed90c38 __1cHnmethodVcleanup_inline_caches6M_v_ (fa5f7f88, fa608940, 1, 0, fa400000, 6) + 1ac
    fede18b4 __1cONMethodSweeperFsweep6F_v_ (2cf38, 0, ffffffff, ff1cf1fc, ff1c66e8, fede1d44) + 1b0
    fede1e6c __1cUSafepointSynchronizeFbegin6F_v_ (2cf38, ff1ba138, 5000, 50dc, 5000, 525c) + 248
    feef1fd4 __1cIVMThreadEloop6M_v_ (4400, 4000, 4324, 4000, 42b0, 3800) + 3d4
    feef1ae4 __1cIVMThreadDrun6M_v_ (e2d20, 2, 40, 0, 40, 0) + 8c
    fee6575c _start   (e2d20, ff270200, 0, 0, 0, 0) + 134
    ff3758c0 lwpstart (0, 0, 0, 0, 0, 0)
    =============================================================================================
    Second pstack
    =============================================================================================
    ----------------- lwp# 2 / thread# 2 --------------------
    fed41180 __1cXvirtual_call_RelocationIparse_ic6FrpnICodeBlob_rpC5rppnHoopDesc_pi_nNRelocIterator__ (0, ff1b9664, ffffffff, fc4ffcb8, a6f2cc, fc4ffbd0) + 6a0
    fed46318 __1cKCompiledIC2t5B6MpnKRelocation__v_ (a6f2c8, fc4ffd24, fc4ffd4c, e802, 0, 6) + 38
    fed90c38 __1cHnmethodVcleanup_inline_caches6M_v_ (faded4c8, fadf2c80, 1, 0, fa400000, 6) + 1ac
    fede18b4 __1cONMethodSweeperFsweep6F_v_ (2cf38, 0, ffffffff, ff1cf1fc, ff1c66e8, fede1d44) + 1b0
    fede1e6c __1cUSafepointSynchronizeFbegin6F_v_ (2cf38, ff1ba138, 5000, 50dc, 5000, 525c) + 248
    feef1fd4 __1cIVMThreadEloop6M_v_ (4400, 4000, 4324, 4000, 42b0, 3800) + 3d4
    feef1ae4 __1cIVMThreadDrun6M_v_ (e2d20, 2, 40, 0, 40, 0) + 8c
    fee6575c _start   (e2d20, ff270200, 0, 0, 0, 0) + 134
    ff3758c0 lwpstart (0, 0, 0, 0, 0, 0)
    =============================================================================================
    Has anyone ever seen anything like this? I'm trying to figure out if this is caused by something we're doing, or something relating to our environment and jvm options. Any ideas?

    Thanks for the reply - I'm testing our app with the +UseConcMarkSweepGC now in our test environment to make sure it doesn't cause any problems there.  Unfortunately the only place we've had this problem is on the production server, so it's extra difficult debugging this. 
    We're using the following memory options:
    -ms512m -mx512m -XX:NewSize=128m -XX:PermSize=192m -XX:MaxNewSize=128m -XX:MaxPermSize=192m -XX:SurvivorRatio=8and the following debugging options, as we've also been seeing OutOfMemoryErrors ( see http://forum.java.sun.com/thread.jsp?forum=37&thread=522354&tstart=45&trange=15 )
    -verbosegc -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintHeapAtGCBTW, which c++filt version and options are you using? Our Solaris boxes only seem to have the GNU version installed. I was trying to run that on some of the other stack traces and wasn't getting anywhere, and didn't know if because it was GNU version wouldn't work on something compiled with the Sun compiler.
    Thanks!
    --Andy                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       

Maybe you are looking for

  • Cannot forward email from iPhone 4

    My wife cannot forward email. I looked at my iPhone 4s and it has a bar at bottom. Hers doesn't. She hates upgrades and I suffer for it. But I am in the trenches and I am still a believer in the product. Can I sit down now? Oh yeah, the question: Why

  • Shared variables not updating in exe

    Hi, I've created a project with 2 vi's, they share data via Networked Shared Variables, one vi writes while the other reads. The data is passed between the 2 vi's whilst running in the Labview 2009 SP1 development environment, but when I create an ex

  • Lens Lists in Lens Correction Lightroom 5 in Mac

    I have a long list of lenses in Lightroom 5 on my PC but with the Mac there is  very limited list for Nikon. None of my lenses appear in this on MacSame version. Can I download an updated list into the menu?

  • Using Brother printer, can't print on both sides.

    I installed OS 10.5 and now my printer is giving me almost no options other than just to print, including no option to print on both sides. Please help! Thanks.

  • I am unable to download and open a software program, Exam Soft...

    I have an HP Pavillion dm4 with windows 7, i5...i know very little about computers. Desperately need to fix the issue. It will download ExamSoft but it won't open up.