Description:

PMD scans Java source code and looks for potential problems like:
* Possible bugs: empty try/catch/finally/switch statements
+ Dead code: unused local variables, parameters and private methods
+ Suboptimal code: wasteful String/StringBuffer usage
+ Overcomplicated expressions: unnecessary if statements, for loops
that could be while loops
+ Duplicate code: copied/pasted code means copied/pasted bugs

PMD has plugins for JDeveloper, Eclipse, JEdit, JBuilder, BlueJ,
CodeGuide, NetBeans/Sun Java Studio Enterprise/Creator, IntelliJ IDEA,
TextPad, Maven, Ant, Gel, JCreator, and Emacs.