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 methods
- Empty if/while statements
- Overcomplicated expressions - Unnecessary if statements, for loops that could be while loops
- Sub optimal code - wasteful String/String Buffer usage
- Classes 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. from WikiPedia
- PMD Can be integrated with Eclipse (see below), Maven (maven-pmd-plugins), Ant (Ant task).
- PMD is an engine, rulesets parse code and issue a message and level if rules are violated.
- PMD is notable because you can write your own rules using XPath expressions over an XML version of the parse tree
- PMD has a duplicate code detector CPD which is quite fast and accurate to locate dangerous CUT and Paste code sections.
List of rule sets