See
<http://java.sun.com/docs/books/tutorial/uiswing/components/progress.html>

http://java.sun.com/docs/books/tutorial/uiswing/components/progress.html

/Thomas

Usuallay a Swing Timer is used to poll the object you want to monitor
the progress on and use this value on the progress bar.

class MyProgressObject {

...

  public int getProgress() {
    //Calculate some progress value here
    ...
  }

...

}

Timer ProgressUpdater = new Timer(..) {
  public void actionPerformed(ActionEvent ..) {
    myProgressBar.setValue(myProgressObject.getProgress());
  }
}

Make sure you use a Swing Timer, since the actionPerformed body is then
executed in the EDT..

Hope this is useful

/Mikael