I've been developing SolView and JKstat for a while. Over time, code goes stale so I thought it was time for a good cleanup.
Rather than trying to spot all the bad code by eye, I sought a tool that would find unused code, unused imports, and generally find problems automatically. (And I already run javac with the -Xlint:unchecked flag, and use the OpenSolaris jstyle utility.)
After a little looking around, I found PMD and find it very useful. It's done an excellent job of finding poor code. Fortunately, it hasn't found any killer bugs, but has pointed out plenty of cases where I've been sloppy. One bad habit I've got into is unnecessarily declaring class fields rather than local variables, for example. So I recommend it. (I don't regard this as the end of the exercise - I plan to keep looking to see what other static analysis tools can tell me about my code.)
As a result, I've released new versions of SolView and JKstat that have been cleaned up. I haven't done much else to JKstat, although I have enabled the ability for SolView to just show the panel you're primarily interested in (such as just the services, or the general information) which makes it rather lighter weight.