Look at this nice Java Demo:

http://weblogs.java.net/blog/alexfromsun/archive/2007/11/debug_swing_rep.html

These here are other useful links:

• http://weblogs.java.net/blog/alexfromsun/archive/2006/02/debugging_swing.html
• http://elliotth.blogspot.com/2005/05/automatically-detecting-awt-event.html