Hi, this is a general question. I read in the documentation that Hibernate does Collection mapping with lazy loading by silently replacing Set, List, etc. with the respective Hibernate extensions. That is great. But what if my associations in my domain model use user-extended associations already?

Our beans all use a user extended collection called AssociationSet. Will I have to replace this and remove all the extra functionality in order to use Hibernate's collection lazy loading? Or would there be a way for me to integrate this with Hibernate's collection implementations more gracefully?

I was thinking of using the Hibernate collections directly and explicitly and then extending those. But that would make all the business objects dependent on Hibernate.

Ideally I think the hibernate collections would be on the fly generated extensions, just like the persistent entity classes are. What's the thinking here?

I had the exact same problem in migrating to Hibernate. Our domain model only refers to the collection interfaces (e.g. List), but we have custom implementations that would take a long time to replace with a different strategy.

I solved the problem with a bit of a "hack" solution, because I didn't see a way that user customization was intended with the persistent collections. This would be a nice extention point, BTW, hint hint. :-)

What I did was extend the Hibernate implementations to add some of my own functionality (e.g. extended the Bag class). But in order to get Hibernate to use the class, I had to also extend the corresponding Bag class in the mapping package and the BagType class in the type package.

Then I had to programmatically loop through the objects in the Configuration instance (after loading all the config files) and replace "Bag" mappings with my own "Bag" extension. It was a bit of a pain.

Please open up a feature request in Hibernate3 branch for this, lets see what and if any solution can be found. I'd agree that it at least needs documentation.

I need the same feature of able to user extended collection.

Seems to me feature request HHH-83 was implemented.
Can anyone give an example of how to map a collection
using user extended collection?