Using abstract class in Set?

[Janus Engstrøm]

Hi!

I have the following classes:

abstract class A {
...
}
 
abstract class B extends A {
...
}
 
class MyClass1 extends B {
...
}
 
class MyClass2 extends B {
...
}
 
class MyClass3 extends B {
...
}
 

Too, I have a class like this:

class MySetClass {
   Set<A> mySet = new HashSet<A>();
...
}

I'm mapping the classes A, B and MyClasses using the union-subclass strategy, as I'd like all variables in A and B to be replicated to the MyClasses. Also, I don't want A and B to have a table of their own, so they are marked with

abstract="true"

. The mapping works like a charm, the tables created are exactly as I want them to be.

I map the MySetClass as following:

...
<set name="mySet" cascade="save-update">
   <key column="set_id"/>
   <one-to-many class="A"/>
</set>
...

The problem arises when I'm trying to persist the Set in MySetClass:

 
Session s = ...
 
MySetClass msc = new MySetClass();
 
A a1 = new MyClass1();
A a2 = new MyClass2();
 
msc.getSet().add(a1);
msc.getSet().add(a2);
 
s.save(msc);
s.getTransaction().commit();

yields the following exception:

Invalid object name 'A'.


I assume the exception arises because Hibernate looks for a table named 'A', but it doesn't exist because it's abstract (and therefore marked with abstract="true" in the mapping file).

What am I doing wrong here? I cannot be that Hibernate cannot figure out what to do in the example above? It's just trivial inheritance.


Regards,

Janus