gpl-util is "a collection of miscellaneous classes and methods that generally come in handy in all sorts of situations." gpl-util is a dependency of jboss-3.2.7 and jboss-4.0.2.
Now maintained in the experimental overlay.
Now maintained in the experimental overlay: https://gentooexperimental.org/svn/java/gentoo-java-experimental/dev-java/gjt-jpl-util/