I vave a class Instruction that is mapped to an INSTRUCTION table.
The class instruction has a property that is a state. I want this state to be a class herarchy that has its own behavior depending on the specific instance.
how can I make hibernate instanciate the appropied instance based on the value of the state field in the INSTRUCTION table.
Note that State is not a persistent class so it has no mapping of its own.
State is like a Component or a custom type that has to be instanciated by hibernate on the base of a field value in a table.

Hello,

you could take a different approach.
Define state as a component holding an identifier.
Your state Class could call a factory depending on the value of the field. So the method of your State class does not implement the behaviour itself but call the Logic class generated by the factory.

Please rate, if this helped.
Regards Sebastian

Thanks,

Actually I did allready take that approach. Except that y just left the state as a text field and called the fabric from the INSTRUCTION entity. Actually is the same, thanks anyway.

Besides, it would be nice to be able to subclass components and propertyes. Could this be asked as a feature in hibernate ?

This is allready implemented. You can define custom types. See the examples for Hibernate Caveatemp...

I know that you can define custome types. But I mean what I was asking before. That you could map an interface as a component or property and hibernate would instanciate the concrete class based on a discriminator field in tha main table.