In a normal bidi ManyToMany association, there is a Join table.

Can I map an additional class to the Join table.
The point is, I can directly manipulate the association more efficiently.

Sure, I know that, I can do it by breaking the ManyToMany
to two bidi OneToMany with one intermediate Entity class.

Maybe using Map and @MapKeyManyToMany

I'm fighting through this same issue. I'm working with a legacy schema and have the following:

Customer (table)
customer_id (int)

Address(table)
address_id (int)

CustomerAddressLink (table)
customer_id (int)
address_id(int)
mailing_address (bool)
shipping_address (bool)
begin_date (date)
end_date (date)


So, I need to actually get at the data in the mapping table. I've tried mapping the Address table with the AddressLink table in a <join> element. However, I'm finding that Hibernate is actually joining the address link table twice in the generated sql, which is killing performance. I assume it's joining once to satisfy the many to many mapping, and again to populate the entity. What's the *best* way to build this mapping such that I'll still be able to use filters to filter by values in address or the link table (I don't want to use criteria because they cause an outer join, I want the addresses to be lazy loaded).

map the association table as a regular entity

Thanks!

However, if I map the association table to a new entity.
Is it valid to left the original "@ManyToMany" mapping
on the owning side and inverse side intact?

How I HAVE to change both @ManyToMany mapping to
@OneToMany mapping and referencing the new entity (Which mapped
to the association table)?

you need to change them to @OneToMay mapping since the "association entity" has a one to many assoc with the associated entities