I'm using Hibernate 2.1.6, and trying to maintain an audit trail for an object. The object is called Person, and it has a many-to-one association to Address (cascade all, unidirectional).

The webapp lifecycle for this process follows:


1) Retrieve the object from the database, convert to a form object.
2) Send to the user; user submit changes.
3) Load the original object from the database to track the changes made to the object by the user. The form properties are copied to the object retrieved. (An interceptor handles the onFlushDirty call.)
4) Save the updated Person object with saveOrUpdateCopy(Object).

When I save the object, I get a NonUniqueObjectException because the Address instance is already associated with the Session. The saveOrUpdateCopy call doesn't seem to cascade calls with saveOrUpdateCopy, but with saveOrUpdate. How can I get around this NUOE problem?

Ideally, there is a generic way to handle this, since I want to audit most of the objects in my domain model. Any help is appreciated. I've searched the forum, but most of the responses are pretty terse.

Yes, this is really a bug in the current implementation of saveOrUpdateCopy(). Its one that will get fixed soon.

Can you suggest a short-term workaround, or some hints as to the patch required? I'm familiar with the source and would happily work on it.