Hello HaoZhe,
I've got a couple more thoughts for you on the IDE. I exclusively use Linux and have tried a variety of IDEs so here's my two cents.
Eclipse is good and free. If you're used to a visual IDE this one is for you. The only real problem I had with it is that it is HUGE, both in terms of download size and resource usage. If your machine isn't a newer one it can be quite slow. For example, I've got a Pentium II 266 MHz with 320 Mb and an 8.5 Gb IDE drive and despite the fact that I liked Eclipse very much, it just wasn't fast enough for me.
NetBeans seems like it could be quite comparable to Eclipse, but for me it lacked something. Maybe it was the clutter of the interface, I don't know, but I never liked it as much as Eclipse. It's GUI editor seems like it could be useful, though.
jEdit with a variety of plugins is a bit simpler, smaller, and quicker than either of the previous. With the right plugins you can actually get something fairly usable, though admittedly it will lack some of the more sophisticated features of Eclipse.
Emacs with
JDEE is a possibility, but probably only if you already like Emacs. The JDEE is fairly good, though it does lack good debugger support (I believe this is the focus of the next release of JDEE).
Anyway, there are a lot of options and people here that can help you with any of them, so good luck.
Regards,
Jay Bromley