Hibernate version:
3.1.1

In the following forum topic: http://forum.hibernate.org/viewtopic.php?t=950827, giulio.vezzelli asked about how to accomplish substitution of a base class by a subclass using table-per-class-hierarchy mapping definitions. I'm looking to do essentially the same thing.

I'd like to define a <class> mapping in my core product, then allow customizations of my product to define a <subclass> mapping that extends and essentially replaces the base mapping to the same table. At no time should the base class ever be instantiated if there's a subclass defined with the same discriminator value.

I'm using Hibernate 3.x, and I'm a relative newbie at it, but I've searched the docs and can't come up with anything obvious.

I'm trying to come up with a similar system.

There are a few models and controllers I reuse over and over. It would be nice if I could just create a project/jar that would contain these and I can extend them

One of the first problems I ran into was relationships.

I have a class EmailLog which has many-to-one relationships between BaseUser and Email.
I marked BaseUser as @EmbeddableSuperClass because for each other application I want to extend it and put more columns in the User table. But if I do this, then EmailLog cannot find the User Entity. Granted I can promote BaseUser to an Entity and have another class altogether, but I would prefer not to do that.

Any ideas?

Has anyone done something like this before?