Decompile java classes automatically with JadClipse

1. Download the latest version of JAD that works with your Operating System from http://www.kpdus.com/jad.html#download

2. Unzip the JAD executable to a memorable place on your hard drive,
    I just stuck mine in the bin directory of the JDK

3. Head over to http://sourceforge.net/project/showfiles.php?group_id=40205 and download the version of the Jadclipse jar that matches your eclipse version, lots of choices here 3.1, 3.2, and 3.3 are covered.

4. Copy the jar file over to your eclipse/plugins directory, this all depends on where you unzipped and installed Eclipse.

5. If you’re workspace was open during all of this, close it and reopen it, if not open it.

6. Click Window - Preferences

7. Expand +Java - Click on JadClipse

8. In the Path to decompiler put in the full path to JAD, or put jadin the path variable for your OS.
    For example, C:\ProgramFiles\Java\jdk1.5.0_05\bin\jad.exe

9. Now go looking in Open Type - Ctrl + Shift + T –  for a class you know is in a jar or compiled in your workspace and voila it should open decompiled, classes will also decompile during navigation of method calls from the Console, or their calling classes and during debug.