Using join() to Wait for a Thread to Die

	Chapter 9 - Threads and Swing
	Java Thread Programming
	Paul Hyde

Copyright 1999 Sams Publishing

---

Using SwingUtilities.isEventDispatchThread()

If you have code that must (or must not) be called by the event thread, you can use the SwingUtilities.isEventDispatchThread() method:

public static boolean isEventDispatchThread ()

This static method returns true if the thread that invokes it is the event thread, and returns false if it is not.

If it is critical that only the event thread calls a particular method, you might want to put some code like this at the beginning of the method:

if ( SwingUtilities.isEventDispatchThread () == false) {

    throw new RuntimeException(

        only the event thread should invoke this method);

}

This way if any thread other than the event thread calls the method, a RuntimeException is thrown. This step can help safeguard against dangerous code that works most of the time when called by a thread other than the event thread.

A downside to this method is that it takes a little bit of time to execute. If you have some code where performance is critical, you might want to skip this check.

Toc