I've stumbled upon the DJ project a really nice tool.
I was looking for something to manage to place swf files inside a java application with the possibility to integrate the two worlds.
There is a lot of stuff well done in flash or flex around and many times is faster to get wanderful looking widgets using Flash than using Java.
The problem with mixing languages is that integration is not so easy.
The DJ project solve this with a nice approach: there is not only a JFlashPanel, but also a Video panel and browser panel (which is the base for the Flash one).
I'm experimenting it.
More in a few days.