Flex and Java have always fit together very nicely. Connecting from Flex to a Java back-end is pretty straightforward whether you are using plain old Java beans, Spring beans, or EJB session beans. I’ve created a video and some sample code that shows you how to connect Flex to a Java EE system using BlazeDS. This video walks though a real-time collaborative Whiteboard application that runs in the browser, on the desktop, and on mobile devices. Check out the video and let me know what you think.

From http://www.jamesward.com/2011/03/08/integrating-flex-and-java-ee-with-jboss/