Windows has a set of reserved words in file names that cannot be used as a file or a directory name. This little javac add-on proactively looks out for those problematic names in your package names and flag them as errors.
Simply add this jar to your classpath when you compile your source code. There's no need to bundle this jar at your runtime. Maven users can add this as an optional dependency (or non-optional, if you want the check to be active on everyone else who depends on your project.)
<dependency> <groupId>org.kohsuke</groupId> <artifactId>windows-package-checker</artifactId> <version>...</version> <optional>true</optional> </dependency>