JArduino might be a good starting point for you, as it would allow you to write Java programs that interact with an Arduino board. The Java API provided by JArduino is fully aligned with the Arduino API. Then, once you get used to the Java API, it should be easy to switch to plain Arduino programming (as pointed out, the C/C++ -based Arduino is not that far from Java, anyway). Be aware that with JArduino you do not really program the micro-controller itself (your main logic would run on your PC and the Arduino would simply be "controlled" without any advanced logic running on the board).
