SpotBugs
A tool for static analysis to look for bugs in Java code
...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.