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][1] 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.
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 [1]: http://code.google.com/p/jbossflex/