Checking Java Programs

Static (Class File) Checking with FindBugs™

FindBugs was written at the University of Maryland^[5] as a tool to analyze compiled Java programs. Because it looks at the byte code rather than the source code,^[6] it can find errors that source-based tools like PMD cannot, so the two programs complement each other (though they do overlap quite a bit). Like PMD, FindBugs can be used as a command-line tool, an Ant task, or an Eclipse plug-in. Unlike PMD, FindBugs provides a standalone GUI client; it does not provide plug-ins for Maven or for other IDEs. The FindBugs GUI provides its own project mechanism. I have not found this useful because my projects are already organized by the IDE I use, but if you're not using the supported IDE (Eclipse), you may find it useful.

Did you know...?

As just one example, FindBugs finds this problem:

"HE: Use of class without a hashCode() method in a hashed data structure (HE_USE_OF_UNHASHABLE_CLASS)

A class defines an equals(Object) method but not a hashCode() method, and thus doesn't fulfill the requirement that equal Objects have equal hashCodes. An instance of this class is used in a hash data structure, making the need to fix this problem of highest importance."

Command-Line Usage

Getting started with the command-line interface (CLI) version of FindBugs can be as simple as downloading and extracting a Zip archive from the FindBugs Project page (http://findbugs.sourceforge.net) and running the provided batch file or shell script. By default this script will ...