Hi List,

I'm using hibernate with the hibernate entity manager and annotation. And 'am getting the exception below.The problem seems to be in that my VersionedPersistentObject class inherits from a Map implementation. Hibernate seems to think that a class which implements Map is a dynamicaly mapped entity and because it cannot find a special key, it just
refuses to persist the object.

I have the feeling that this is not conformant with the EJB3 spec (Entities may extend non entity classes). What do you think about it? Should I report this as a bug?

Here are the details:

Hibernate version: 3.2.2

Entity Classes:
@MappedSuperclass
public abstract class VersionedPersistentObject extends HashMap<Object, Object> implements Serializable {
private Long id;
private Long version;

@Id
@GeneratedValue(strategy=GenerationType.AUTO)
public Long getId() {
return id;
}

protected void setId(Long id) {
this.id = id;
}

@Version
public Long getVersion() {
return version;
}

protected void setVersion(Long version) {
this.version = version;
}

@Override
public String toString() {
return toStringBuffer().toString();
}

/**
* @return Returns the string buffer representation of self. This method is used
* in {@link #toString()}}
*/
protected StringBuffer toStringBuffer() {
return new StringBuffer()
.append(getClass().getName())
.append("[")
.append("id: ")
.append(getId())
.append(", ")
.append("version: ")
.append(getVersion())
.append("]");
}
}

@Entity
@Table(name="events")
public class Event extends VersionedPersistentObject implements IEvent {
private String title;

public String getTitle() {
return title;
}

public void setTitle(String title) {
this.title = title;
}

@Override
protected StringBuffer toStringBuffer() {
return super.toStringBuffer()
.append("[")
.append("title: ")
.append(getTitle())
.append("]");
}

public void copyTo(Event event) {
}
}

Code between sessionFactory.openSession() and session.close():
em.getTransaction().begin();
Event e = new Event();
e.setTitle("Title");
e.copyTo(new Event());
em.persist(e);
em.getTransaction().commit();

Full stack trace of any exception that occurs:

Exception in thread "main" javax.persistence.PersistenceException: org.hibernate.HibernateException: could not determine type of dynamic entity
at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:641)
at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:218)
at com.ls.hibernate.EntityManagerTest.main(EntityManagerTest.java:22)
Caused by: org.hibernate.HibernateException: could not determine type of dynamic entity
at org.hibernate.impl.SessionImpl.guessEntityName(SessionImpl.java:1764)
at org.hibernate.impl.SessionImpl.getEntityPersister(SessionImpl.java:1338)
at org.hibernate.engine.ForeignKeys.isTransient(ForeignKeys.java:180)
at org.hibernate.event.def.AbstractSaveEventListener.getEntityState(AbstractSaveEventListener.java:487)
at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:70)
at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:38)
at org.hibernate.impl.SessionImpl.firePersist(SessionImpl.java:618)
at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:592)
at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:596)
at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:212)
... 1 more

public String guessEntityName(Object object) throws HibernateException {
errorIfClosed();
String entity = interceptor.getEntityName( object );
if ( entity == null ) {
if ( object instanceof Map ) {
entity = (String) ( (Map) object ).get( DynamicMapInstantiator.KEY );
if ( entity == null ) {
throw new HibernateException( "could not determine type of dynamic entity" );
}
}
else if ( object instanceof Element ) {
// TODO : really need to keep a map of nodeName -> entityName, but that would mean nodeName being distinct
entity = ( (Element) object ).getName();
}
else {
entity = object.getClass().getName();
}
}
return entity;
}

yes, please open a JIRA issue with a minimal test case.