JOptionPane.showOptionDailog Hangs Application

Question

Hi,
JOptionPane.showOptionDailog hangs application(In JDK1.3.1) when used in Threads..
Is there anyway to get rid of this..
Thanks,
Sridhar.

Answer 1

So, as I understand you have following situation:
1. You have the GUI event thread (you did not created it explicte - once you did shown first component it was created by Swing)
2. You have, lets call it worker thread which does some work in background and can detect, that you must ask user for
password. This thread also does something, what you don't wan't to stop while user types password.
The critical situation is:
- worker thread detecects, that should ask for password and displays modal JDialog. This way the only active GUI part is this dialog and thread blocks, waiting (since invokeAndWait()) for user to finish typing - this way it can't process what it should.
For me the solution is:
- make sure, your worker thread can work even if password is not set - this way it can work while user is typing. It should be able to send password request, return to work and recive password;
- instead of using JOptionPane subclass JDialog:
class CPswPrompt extends JDialog
          private YourWorkerThreadClass worker;
   public CPswPrompt(YourWorkerThreadClass worker, Frame owner)
         super(owner);
         this.worker =worker;
       JButton ok = ...
       ok.addActionListener(new Ac...
                   public void actionPerformed (ActionEvent e)
                            worker.setYourUserPassword(....); //<<--- here you will pass pasword to worker thread.
};The show it with invokeLater.
if you make this dialog non-modal, you will have your GUI responsive and thread working.