I have a question to add to this.

Since I am developing a game in Java for PC/Mac/Linux, what would it take to make it android compatible? Just implement the android SDK or something?

Not quite. The reason is because Android is designed very differently from a normal PC, despite it being Linux. In Android, you no longer focus on making a program/application, but instead you focus on making activities. Additionally, there's no "main loop" in Android. You receive input from event handlers, and can set a timer/flag to repeatedly call you drawing function, but there's no "main loop." Also, input is quite different, because you don't have a traditional mouse, but instead have "pointers" that go down, move, and then up. Android only supports up to OpenGL ES 2.0, so you have to make sure you're using that (and you may have to make a few changes if you port from some OpenGL library to Android's OpenGL libraries).

You don't have to rewrite your game from scratch if porting it to Android, but if you aren't thinking about Android from the very beginning and designing it to work on Android from the start, you'll probably have to make some significant changes to your project.