SpotBugs
A tool for static analysis to look for bugs in Java code
...SpotBugs is a fork of FindBugs (which is now an abandoned project), carrying on from the point where it left off with the support of its community. Please check the official manual for details. SpotBugs requires JRE (or JDK) 1.8.0 or later to run. However, it can analyze programs compiled for any version of Java, from 1.0 to 1.9. To build the SpotBugs plugin for Eclipse, you'll need to create the file eclipsePlugin/local.properties, containing a property eclipseRoot.dir that points to an Eclipse installation's root directory (see .travis.yml for an example), then run the build.