참조: http://www.redhat.com/docs/manuals/jboss/jboss-eap-4.2/doc/Server_Configuration_Guide/Class_Loading_and_Types_in_Java-LinkageErrors___Making_Sure_You_Are_Who_You_Say_You_Are.html#LinkageErrors___Making_Sure_You_Are_Who_You_Say_You_Are-Classes_demonstrating_the_need_for_