If you're just learning, a decent text editor and the terminal are your friends. I think this goes for pretty much any text based language. Avoid IDE's for now until you understand how everything works. Once you know, then start looking for IDE's if you want. As for Java ide's there are more options than you can shake a stick at, google will give you a brief list. Also consider that many text editors will allow you to run scripts from right inside the editor which, when set up properly can take a lot of the busywork out of developing, but also avoid the whole footprint of a giant IDE setting.