hi, I just ran into the same thing. But I have managed to solve it eventually.. The problem is, that hiddenValue is not a public field, so the MyApp.java should call getDeclaredField instead of getField. And the fact that javap doesn't see it, is because it reads the String.class from the rt.jar. If you call javap -bootclasspath <path.to.new.string> java.lang.String then you will see the 'hiddenValue' field View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4163224#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...