In our application database, we have few lookup tables, such as State, AddressType, PhoneType, and so on. They are read only and pre-loaded. The problem I am having is that when I save objects, I get:

com.mytest.DAOException: net.sf.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session: P, of class: com.mytest.AddressType

This happneded when I tried to save two objects, Person and Organization and the Address is the association. That means Person and Organization all have Address attribute. In one session, the Address has State and AddressType and they are the same record. According to Hibernate, it is not allowed.

Help?

I feel your pain, we have had a lot of those issues as well. Maybe it is an application design floor on our part. Apples and Oranges.

It seems like Hibernate uses == to compare object references instead of equals() to compare object contents.

I wrote a little utility to scan an object graph and look for objects with different references, but are equal using equals() and pick one of n of those instances and do a reassign through the entire object graph so that only one unique instance exists. So before I do any save/saveOrUpdate I run this utility to update references. It takes around 40/50 ms for the first round and thereafter I get mostly 0-15 ms for the update to complete.

This does require your object to define it's own equals() method though.

Anyway this sorts out this nasty exception. If you want the source my mail is ri.so@webmail.co.za