Can I intercept "System.exit" in a spawned GUI thread?

Question

I am writing a large GUI application that optionally spawns other GUI threads. These spawned threads are special-purpose text editors. It is important that the editor knows when it is about to be closed, so that it can prompt the user to save a modified file.
The editors are based upon javax.swing.JFrame, and I have overridden the "windowClosing" method of a WindowAdapter to check file status and prompt when necessary. This method performs as desired when I close the editor window manually. However, when I close the main application (which calls System.exit(0) ), the editor frames also close without any invocation of my windowClosing method.
Is there any way the dependent editor JFrame can be alerted that the virtual machine is about to be ended? I could probably keep a list in my main application of all the dependent processes that need to be cleanly ended, but it would be much simpler (and so much more object-oriented) if the dependent thread could take care of itself!

Answer 1

I was not aware of the Frame.getFrames() method; this is apparently good enough to find all the dependent windows I have created. Thanks for pointing this out.
As to the spawned threads, perhaps you could comment on my method. I was actually hoping to open the editors as independent applications that would persist after the main GUI was closed. To do this, I gave my editor class an associated static Runnable, like so:
   public static class Starter extends Thread {
         String[] arguments = new String[0];
         public void run() {
            MyEditor re = new MyEditor();
            if( arguments.length > 0) re.setFileName(arguments[0]);
            re.setVisible(true);
         public void copyArguments( String[] args) {
            arguments = Arrays.copyOf(args, args.length);
   }which I invoked from my main GUI in the following code:
   Starter starter = new Starter();
   String[] startArgs = {"myfilename.txt", "more parameters"};
   starter.copyArguments(startArgs);
   starter.setDaemon(false);
   starter.start();This does indeed start the editor, but it is in the same virtual machine, since the editor stops when the GUI stops. Is this method setting me up for trouble? Is there a way to do what I originally wanted, starting the editor in a new virtual machine?