http://innig.net/macker/
Macker is a build-time architectural rule checking utility for Java developers. It's meant to model the architectural ideals programmers always dream up for their projects, and then break -- it helps keep code clean and consistent. You can tailor a rules file to suit a specific project's structure, or write some general "good practice" rules for your code. Macker doesn't try to shove anybody else's rules down your throat; it's flexible, and writing a rules file is part of the development process for each unique project.
PMD
http://pmd.sourceforge.net/
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
