PMD is a static ruleset based Java source code analyzer that identifies potential problems like:Possible bugs - Empty try/catch/finally/switch blocks.Dead code - Unused local variables, parameters and... More

PMD is a static ruleset based Java source code analyzer that identifies potential problems like:Possible bugs - Empty try/catch/finally/switch blocks.Dead code - Unused local variables, parameters and private methodsEmpty if/while statementsOvercomplicated expressions - Unnecessary if statements, for loops that could be while loopsSuboptimal code - wasteful String/StringBuffer usageClasses with high Cyclomatic Complexity measurements.Duplicate code - Copied/pasted code can mean copied/pasted bugs, and decreases maintainability.While PMD doesn't officially stand for anything, it has several unofficial names, the most appropriate probably being Programming Mistake Detector.Typically, PMD errors are not true errors, but rather inefficient code, i.e. the application could still function properly even if they were not corrected.  [edit]  Less