Hibernate Envers-如何审核具有@OneToMany关系的实体中的更改？

Question

Lets say I have two entities, A and B. A has a @OneToMany relationship to B and I have audited all the properties in B. When I use Envers to obtain the revisions all I get are the changes in the relation between A and B but I also need to obtain the changes in B's properties. Is there a way todo this?

Thanks in advance!

Answer 1

I am working off the presumption of the following mappings:

@Entity
@Audited
public class EntityA {
    /* other properties & getters/setters */
    @OneToMany(mappedBy = "a", cascade = CascadeType.ALL)
    private List<EntityB> bList;
}

@Entity
@Audited
public class EntityB {
    /* other properties & getters/setters */
    @ManyToOne
    private EntityA a;
}

Anytime you add/remove an EntityB from EntityA , this will trigger a revision change associated with EntityA as well as the associated EntityB that is added/removed due to the relationship.

But if you decide you want to modify some attribute of EntityB that has no direct impact upon EntityA , there will only be a revision generated for EntityB and not EntityA , see below.

entityManager.getTransaction().begin();
final EntityA a = entityManager.find( EntityA.class, aId );
for ( EntityB b : a.getbList() ) {
    b.setName( b.getName() + "-modified" );
}
entityManager.merge( a );
entityManager.getTransaction().commit();

If you need the individual revisions of EntityB in this case, you'll need to actually specifically query for EntityB through the AuditReader interface instead.