I have written a few games in the past. A recent example is Dune II – The Maker. I have written a platformer (in QuickBasic even..) and so forth. You may even consider RealBot a ‘game’ (although it is more a computer controlled opponent).
I haven’t really tried to write any games in Java. Although I do program in Java quite a lot these days. Especially for the web. But it seems there is (for some time now) a game library that I might try out.
The library is called Slick and when looking at its website, forum and documentation (API and get-started) it has some promise!
I have tried setting up a simple project with maven, including slick stuff, and wrote a little engine that only draws some blocks and bounces them at the borders of the screen. So far it works great.
Although writing games now is not my priority at all, I will get back to this once I have finished my thesis about Software Quality.
In the meantime, you might want to consider looking at Slick. Give it a chance!