rails is a good choice - it is simple for simple things, while allowing more complex things to be possible (always a good sign). There is a little bit of learning curve initially, but that's true of all frameworks.
If you're happier in Java, you could also look at Groovy + Grails, a very similar framework with a Java slant (groovy is kind of like a cross between java and ruby, and you can mix and match Java and Groovy classes in the same project).
