Source code

addWindowListener(new WindowListener(){
      public void windowClosing(WindowEvent e){
            System.exit(0);
      }
      public void windowActivated(WindowEvent e) { }
      public void windowDeactivated(WindowEvent e) { toFront(); }
      public void windowDeiconified(WindowEvent e) { }
      public void windowClosed(WindowEvent e) { }
      public void windowIconified(WindowEvent e) { }
      public void windowOpened(WindowEvent e) { }
});

Source code

/**
* Call this from class consructor
*/
public void initialize() {
TopThread top = new TopThread();
top.start();
}

/**
* Keep JWindow on top (inner class)
*/
class TopThread extends Thread {
public void run() {
while(true) {
toFront();
/**
* Let 10 milliseconds for other code to execute
*/
try {
Thread.sleep(10);
}
catch(Exception e) {
// Nothing to do
}
}
}
}