Description Missing name Mising name 2011-06-27 22:16:12 EDT

Build Identifier: 2.2.0

My JPA provider is EclipseLink JPA 2.2.0 distributed with Glassfish 3.1.

This is the problematic set of JPA entities :
@Entity
public class EventAttendance {
	...
	@ManyToOne private Person person;
	@ManyToOne private Event event;
	...
}

@Entity
public class Event {
	...
	@OneToMany(mappedBy = "event")
	@MapKey(name = "person")
	private Map<Person, EventAttendance> attendance;
	...
}

@Entity
public class Person { ... }


This is a set of operation that gives erroneous results:
BeginTransaction();
EntityManager em = ...;
Person person = em.find(Person.class, PERSON_ID);
Event event = em.find(Event.class, EVENT_ID);

// This map contains at least the entry:
// Key = Person with id == PERSON_ID
// Value = an instance of EventAttendance
Map<Person, EventAttendance> attendanceMap = event.getAttendance();

// Should return the EventAttendance instance mentioned above, but returns null!
EventAttendance attendance = attendanceMap.get(person);
CommitTransaction();


Digging around in the debugger, I found that the problem is that there exists 2 instances of the same Person entity in the persistence context. These 2 instances reference the same entity which violates the JPA contract.

Changing the Map to a simple List gives the expected behavior whereas the Person instance with id PERSON_ID is shared between the List in Event and em.find(Person.class, PERSON_ID).


Reproducible: Always