"scott.stark(a)jboss.org" wrote : Looking at the MetaMapper class more, its not a registry of mappers. The static getMetaMapper(TypeInfo typeInfo) method derives the MetaMapper from either an attachment on the TypeInfo, or a MetaMapping annotation on the java type (ClassInfo). I'm not sure what the hooks are for introducing an attachment or an annotation on jdk types like javax.management.ObjectName are. ? Hmm well i was rather thinking of adding a static registry for types we cannot easily annotate ourself? So that this is checked before it tries to the process the annotation. I think that would be the easiest way - especially for very basic transformations like this. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4191490#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...