Useful Java Coding Tools [closed]

Question

I was wondering what kind of tools people use to make their coding experience more enjoyable or easy. Especially in java.

Also, what kind of tools would be nice?

EDIT: Let's assume we all use some IDE that supports plugins... :-p

Answer 1

1. An IDE like IntelliJ, Eclipse, Netbeans. If you use IntelliJ, get addicted to Ctrl+Space and Alt+Enter
2. Use debugger
3. Use IDE built-in profiler or plugins like YourKit
4. Build and continuous integration tool, ant, maven, buildr, TeamCity, Hudson, etc
5. Java Coffee at CAFE BABE

Answer 2

FindBugs is a nice tool and there are plugins for many IDE's.