Create a Sonar plugin to integrate the Jlint rule engine

Jlint will check your Java code and find bugs, inconsistencies and synchronization problems by doing data flow analysis and building the lock graph. Jlint is extremely fast - even on large projects, it requires only one second to check all classes! It is easy to learn and requires no changes to the class files. Jlint has been used in an industrial environment and successfully uncovered faults with little effort!

http://jlint.sourceforge.net/