Find Bugs Plugin

Findbugs provides for a quick method of doing static code analysis. It can operate in a stand alone mode and integrates well with eclipse as well. More information on this can be found at
http://findbugs.sourceforge.net/

The installation comes with a number of built-in detectors. Additional detectors can be found at
http://fb-contrib.sourceforge.net/

While these detectors are useful, the real power of FB can be unlocked by writing a custom detector for you code. Below is a step by step tutorial that you can refer to for writing a custom detector for your code.
https://code.google.com/p/findbugs/wiki/DetectorPluginTutorial
http://www.ibm.com/developerworks/library/j-findbug2/

To write your own detectors you would need to know the byte code being generated for your classes and then based on those patterns write a detector which will serve your purpose. One good plug-in to view the byte code for your classes is the Dr. Garbage Byte Code Visualizer. It is available as a eclipse plugin and is very useful during the development.
http://www.drgarbage.com/bytecode-visualizer/

Once you have developed your dectector, testing/debugging it can be easily done using the APIs here

https://github.com/tim-group/test-driven-detectors4findbugs