1) The DTD is not added to deployment archive automatically

2) Even when added manually to places usually scanned by WebappClassLoader (such as WEB-INF/classes, WEB-INF/libs (in a separate jar) etc.), test fails due to the following reason:
java.io.FileNotFoundException: C:\java\glassfish-3.1.2.2\glassfish\domains\domain1\config\test.dtd (The system cannot find the file specified)

For more details, see this thread: https://community.jboss.org/thread/204709