AI is a field of study, and the way to get started (not to sound flippant) is to read quite a bit about it. One of this forum's key contributors, Ernest F Hill has written one or more books on this subject. That would be a good place to start.
In my humble opinion there are programming languages that serve the niche of AI better than Java. In general, declarative languages fare really well when compared to imperative languages. MIT (they have contributed a lot to AI) proponents would go with Lisp. I somehow fancy Prolog.
"Perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away." -- Antoine de Saint-Exupery