It doesn't direct you to any specific materials on the various elements of game design.
I've yet to see a resource that really covers that (properly) - its one of those things you learn through experience by making many mistakes and learning from them. I learned a lot by hanging around in IRC chats and learning on the spot from 'the masters' (people who had already been doing it for a decade). That too revolved around me doing it horribly wrong and being corrected so many times I still feel shame.
I think that's one of the biggest hurdles a lot of wannabe java game designers (such as myself) are facing, that the resources for learning those key elements are pretty sparse, and kind of strewn about in a way that makes them hard to find.
It wouldn't be so sparse if you would open up your 'world' - Java is really a niche and so of course there aren't so many resources available, game development is still the area where C++ (and increasingly C#) is king so if you want proper information, I do suggest you focus on resources targeting C++ and to use your noggin' to translate that back to Java. Its surprisingly easy actually, even C++ books tend to stick to very basic C++ which easily translates and is easily read even if you're not experienced with the language. The only thing you'd have to take a little time with is the concept of memory pointers, which I am -so- glad to be rid of. When you start to pass around the address of a pointer to a pointer, you've had enough.