First, I know this is similar to a couple FAQ items. Of course, that doesn't mean I haven't done something stupid :).

Basically, I have a m to n mapping between a Group and System domain object. The mapping includes an additional attribute, which is State.

Every time I pull back the Set (Group- State for System, or System - State for Group) and later flush, it appears that hibernate is deleting the collection and rebuilding it.

I see these log entries:



I did a check of the logs and did not find any "isdirty" or "dirty" log entries.

Now, my domain object is simple for these Sets. The only time I touch the set is during construction and in the Hibernate setter. The only thing calling the setter is Hibernate. I set the Set to a new HashSet during construction to handle cases when this is a transient object not yet persisted in Hibernate.

Any insight would be greatly appreciated.

Nowhere near enough information.

We would need at least all the mappings and java code.

But it doesn't look to me like Hibernate is deleting the collection and rebuilding it. Looks more like it is just deleting a couple of elements that were removed.

"removed" can sometimes mean that the element did not implememt equals()/hashCode() correctly, or you did something to change the hashCode() after adding it to the set.

I think your post got me thinking in the right direction Gavin. I figured it was something rediculously simple. Anyway, I forgot to implement equals()/hashCode() on the objects contained in the Set. Thank you for the help!