I'm starting to create my own side scroller, in Java. I think I've read that, when you create a game in Java, there is something you can extend your class with, like
Is this true, or can you just use JFrame for your Java games?
To kill two birds with one stone, I would also suggest you look into Artemis, which is an awesome Entity System that works on top of Slick. The site contains some example games to help you get started.