Hibernate - Persisting polymorphic joins
- by Marty Pitt
Hi
I'm trying to understand how to best implement a polymorphic one-to-many in hibernate.
Eg:
@MappedSuperclass
public class BaseEntity {
Integer id;
// etc...
}
@Entity
public class Author extends BaseEntity {}
@Entity
public class Post extends BaseEntity {}
@Entity
public class Comment extends BaseEntity {}
And now, I'd like to also persist audit information, with the following class:
@Entity
public class AuditEvent {
@ManyToOne // ?
BaseEntity entity;
}
What is the appropriate mapping for auditEvent.entity? Also, how will Hibernate actually persist this? Would a series of join tables be generated (AuditEvent_Author , AuditEvent_Post, AuditEvent_Comment), or is there a better way?
Note, I'd rather not have my other entity classes expose the other side of the join (eg., List<AuditEvent> events on BaseEntity) - but if that's the cleanest way to implement, then it will suffice.
