Version property of Parent isn't incrementing if I update child

Question

I'm using JPA 2 with Hibernate 3.x. I have two Entity objects Foo and Bar and the relation is like this -

@Entity
public class Foo{
    @Id
    private long id;

    @OneToOne(cascade = CascadeType.ALL )
    @JoinColumn(name = "bar")
    private Bar bar;

    @Version
    private int version; 
}

@Entity
public class Bar{
    @Id
    private long id;

    private String name;

    @Version
    private int version; 
}

Now my problem is If I loaded Foo from entityManager.find(...) and updated name of Bar like foo.getBar().setName("someAnotherName"); and fire entityManager.merge(foo) then Hibernate fires a update on Bar and increments a version for Bar only. From the object perspective doesn't its a change of the sate of Foo as well and shouldn't it increment the version of Foo as well?

Now I would like to remove the version property from Bar and version of Foo should get incremented if Bar gets updated. How can I achieve this?

Answer 1

In your case not Foo, but entity on which it references has been changed, so there is no need in version increment.

@Version adds optimistic locking capability to an entity and it shouldn't be used as a change counter. The main purpose of this annotation is detecting of conflicting updates, so think twice before doing that.

The only way to override this behaviour is to use [OPTIMISTIC | PESSIMISTIC]_FORCE_INCREMENT