Worker thread not quite working

Question

I had the standard 'waiting for a database' gray box problem. So I put my db calls into a worker thread. It was impractical to use the WorkerThread class that Sun distributes, so I wrote my own (see below). This solved the problem in most but not all cases.
In some situations, the user is looking at one window that overlaps another. When a button on the top window is pushed, the top window is dispose()'d of, and the worker thread is started. In this situation, the gray box problems rears its ugly head, despite the use of the worker thread.
Could that dispose() be causing the problem? Do I need to repaint the remaing window before calling the worker? If so, what command should I use? repaint()? setVisible(true)?
Any thoughts or suggestions would be appreciated.
Barnet Wagman
My worker thread code:
public class BossClass {  // The worker thread is an inner class of this one
        // The following fields get used by the worker thread;
        // could this be a problem? I don't think so.
    private transient byte outcome;
    private transient Object resultObject;
    private transient URL url;
    private transient Thread mainThread;
    private transient boolean allDone;
        // Sends a command to a server and gets a returned object
    public synchronized void send(URL url) throws IOException {
        // ^ I've tried this with and without the synchronized - no difference
     this.url = url;
     mainThread = Thread.currentThread();
     allDone = false;
     new SendThread();
     while( !allDone ) {
         try { Thread.sleep(mnemonaface.Constants.SEND_OP_SLEEP_TIME); }
                    // I've tried the sleep time = 100, 500, 1000 milliseconds
         catch( InterruptedException ix ) {}
    class SendThread implements Runnable, Serializable {
     SendThread() {
         (new Thread(SendThread.this)).start();
     public void run() {
            URLConnection uc = url.openConnection();   
            // Various things get done with the url connection
            allDone = true;
}

Answer 1

Instead of your method and inner class try this :
public void sendURL(URL url) {
     this.url = url;
     Runnable sender = new Runnable() {
          public void run() {
               URLConnection uc = url.openConnection();
     SwingUtilities.invokeLater(sender);
}I hope this helps,
Denis