What is "findbugs"

FindBugs is an open source static code analyser created by Bill Pugh and David Hovemeyer which detects possible bugs in Java programs. Potential errors are classified in four ranks: (i) scariest, (ii) scary, (iii) troubling and (iv) of concern. This is a hint to the developer about their possible impact or severity. FindBugs operates on Java bytecode, rather than source code. The software is distributed as a stand-alone GUI application. There are also plug-ins available for Eclipse, NetBeans, IntelliJ IDEA, Gradle, Hudson, Maven. and Jenkins.

Additional rule sets can be plugged in FindBugs to increase the set of checks performed.