anonymous wrote : Hope paiId isn't a composite key, otherwise you won't be much better off calling it's hashCode() and equals() without overriding them too... No paiId is an Integer. I don't think the problem is my implemention for the equals and hashcode methods. The problem is why the input parameter is always null... do you know why? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4123362#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...