…or so say the makers of FindBugs, an open-source bug detector for Java. When I’m asked to improve the code quality on a project often the first thing I do is to search for “obviously” bad code. By this I mean I look for stuff like String construction (you never need this in Java), incorrect use of static (makes testing hard, could be a sign people are using singletons), and a few others.

FindBugs takes this approach a step further using automated detectors that look for dodgy code. They work by scanning the compiled Java bytecode and looking for suspicious patterns. Running this against my current project found a multitude of sins, my favourite being the “looks right but is definitely buggy” covariant equals. Next best is the “database resource not closed” detector, and the “questionable reference comparison” detector – try manually finding bugs caused by Integer object comparison using == instead of equals()…

FindBugs has definitely found a place in my toolbox, and I’ll be running it regularly to avoid nasty surprises.