I just used the new inheritance feature of EJB3 with the

InheritanceType.SINGLE_TABLE

strategy. There is a column for the type of the entity and each entity has a

@DiscriminatorValue

.

My entities are like:

@Entity
@DiscriminatorColumn(name = "INHERITANCETYPE", discriminatorType = DiscriminatorType.STRING)
@DiscriminatorValue("Partner")
public class Partner ...

@Entity
@DiscriminatorValue("NaturalPerson")
public class NaturalPerson extends Partner ...
 protected String attributeOnlyInNaturalPerson;

I have another entity with a relation to a

Partner

entity (1-n-relation, so that a collection of

Partner

is returned.

If I call

myEntity.getPartner():Collection<Partner>

, I will get entites of type

Partner

. In the debugger, I can see that the attribute

attributeOnlyInNaturalPerson

is loaded from the database and instanciated to the object, BUT if I try to typecast the object to NaturalPerson, I get an ClassCastException.

My current work around is to EntityManger.find(NaturalPerson.class, id) the entity again (this works) but I think this is a performance problem...


Am I doing anything wrong with inheritance and relations, or is this really a bug?

Best regards
Carsten