Closing a JOptionPane Causes a Deadlock in Java Swing

I have an application which开发者_开发知识库 runs OK at most sites. But one site, which is hosting the application on a Citrix Box appears to have a deadlock problem. I ran a profiler on the session and received a surprise. The statement causing the deadlock appears to be a statement which closes a JOptionPane dialogue box. Please see the enclosed display.

So I have three questions:

1. Is my interpretation correct?
2. Any idea of why this can happen.
3. What can I do in code to prevent this from occurring?

Thank you in advance for your help.

Elliott

---

Swing is not thread-safe. Perhaps your app is calling Swing GUI methods from outside of the Event Dispatch Thread.

If you can reduce this to a minimal sample that still reproduces the problem, you will either 1) find the cause yourself in the process, or otherwise 2) end up with a much greater chance of getting help from someone else.

---

1. Don't know, but if it is..
2. Calling GUI methods (update the GUI) off the EDT.
3. Call GUI methods on the EDT.