You said: "obviously Publisher and Purchase classes are the same class!" What do you mean? Are you saying that class Publisher is declared in the file Purchase.java? Could you post the source for Purchase.java? (When posting source code, embed it within 'code' tags. To do this, select the source code and click the Code button above the editor window. Also, use the Preview button to check the formatting before clicking Submit.) View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4241221#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...