Tools for Java game development?

I've had some success with Slick2D in the past (assuming you game is 2D). There is a tutorial series on youtube for it http://www.youtube.com/user/thenewboston/videos?query=slick. I haven't watched it myself but have watched some of the other videos by the same guy and he's pretty good. If you're making a rpg you'll probably want to include a scripting engine. LUA or python are probably the best.