Reddit mentions of Introduction to Programming with Greenfoot: Object-Oriented Programming in Java with Games and Simulations

Try Greenfoot. We used this in my college game design class. Our final project, done over the span of 10 weeks, was to create a game using Greenfoot. You learn a lot of java this way, and the website is great too. There are forums where you can go to ask for help, and the people there are usually really informative. There is also a Greenfoot book on Amazon (I rented it but hardly used it to be honest, though it would have helped a lot) if you want further help, but there are plenty of tutorials on the site.