CodeWarrior, developed and sold by Metrowerks, is a Java development environment. It is required for several of the course projects in CS100J. It is not free.But it's a very good environment for developing large programs, and its program debugging facilities far outperform those of DrJava. Microsoft is rumoured to use it.

If you have your own computer and want to do all your assignments at home, and if you expect to do more Java programming later, then buy Codewarrior at the Cornell bookstore.

Here's a link to a guide to using Codewarrior.

Here's a link to Metrowerks' website.