What is the proper JPA mapping for @Id in parent and unique sequence in base classes

Question

I have a class hierarchy:

abstract DomainObject {
...
    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator="SEQ")
    @SequenceGenerator(name="SEQ",sequenceName="SEQ_DB_NAME")
    @Column(name = "id", updatable = false, nullable = false)
    private Long id;
...
}

BaseClass extends DomainObject {
...
   // Fill in blank here where this class's @Id will use a unique sequence generator
   // bonus points for any sort of automatic assignment of generator names that might 
   //prevent me from having to instrument all my domain objects uniquely
...
}

notes:

• I do not specifically need a base class generator, so if it behooves me to remove it no problem.
• This is an oracle 9i db if that is applicable
• Hibernate 3.4 JPA
• Spring 2.5 is available as well

Thanks

Answer 1

Okay here's how I ended up solving the problem:

Base class:

@MappedSuperclass
public abstract class DomainObject implements Serializable {
 @Id
 @GeneratedValue(strategy = GenerationType.SEQUENCE, generator="SEQ")
 @Column(name = "id", updatable = false, nullable = false)
 private Long id;

 .. rest of class
}

Descendant class:

@Entity
@SequenceGenerator(name="SEQ",sequenceName="SEQ_DB_NAME")
public class BusinessObject extends DomainObject {

 ...

}