Problems with @VersionsJoinTable

[msilva]

I'm trying to use the @VersionsJoinTable annotation in a @OneToMany relationship but it doesn't seem to generate the right table structure (the join table isn't created at all).

My test Entities:

@Entity
@Versioned
public class Entity1{

 @Id
 private Long id;;

 private String prop;

 @OneToMany
 @VersionsJoinTable(name= "joinTable")
 private List<Entity2> entities2;
....
}

@Entity
@Versioned
public class Entity2 {

 @Id
 private Long id;

 private String prop;
....
}

If I use the JPA annotation (@JoinTable) instead, the tables are created correctly, but I encounter problems when fetching the related collection with the VersionsReader.

Am I misusing the annotation?

Thanks,
Marcus

[msilva]

I made some additional tests, now using the hibernate-envers module (version 3.4.0-SNAPSHOT). What I'd really like to do is add extra columns to the join table, so I decided to create an explicit join entity:

@Audited
@Entity(name = "MIDDLE")
public class Middle {
 @Id
 @GeneratedValue
 private Long id;

 @Column(name = "ID_ENT1")
 private Long idEnt1;

 @Column(name = "ID_ENT2")
 private Long idEnt2;

 private String prop; // Extra column

 // Getters and setters
}

Therefore, Entity1 became:

@Entity
@Audited
public class Entity1 {
 @Id
 @GeneratedValue
 private Long id;

 @OneToMany
 @JoinTable(name = "MIDDLE", joinColumns = @JoinColumn(name = "ID_ENT1"), inverseJoinColumns = @JoinColumn(name = "ID_ENT2"))
 private List<Entity2> entities2;

 private String prop;

 // Getters and setters
}

Notice I'm using the regular @JoinTable annotation. My test case is the following:

@Test
public void test() {
 Entity1 ent1 = new Entity1();
 Entity2 ent2a = new Entity2();
 Entity2 ent2b = new Entity2();

 ent1.setProp("prop1");
 ent2a.setProp("prop2a");
 ent2b.setProp("prop2b");

 List<Entity2> list = new ArrayList<Entity2>();
 list.add(ent2a);
 list.add(ent2b);
 ent1.setEntities2(list);

 em.getTransaction().begin(); // Using EntityManager
 em.persist(ent2a);
 em.persist(ent2b);
 em.persist(ent1);
 em.getTransaction().commit();

 Entity1 ent1 = ar.find(Entity1.class, 1L, 1); // Using AuditReader
 System.out.println(ent1.getEntities2());
}

The last command prints an empty list, meaning it wasn't able to fetch the related collection. Looking at the database, I found out that Hibernate generates the tables MIDDLE and MIDDLE_AUD, but only the first one is used (MIDDLE_AUD remains empty all the time).

I also tried to use the following annotation instead:

 @OneToMany
 @AuditJoinTable(name = "MIDDLE", inverseJoinColumns = @JoinColumn(name = "ID_ENT2"))
 private List<Entity2> entities2;

This gives me the following exception:

javax.persistence.PersistenceException: [PersistenceUnit: persistenceUnit] Unable to build EntityManagerFactory
 at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:677)
 at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:126)
 at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83)
 ...
Caused by: org.hibernate.HibernateException: could not init listeners
 at org.hibernate.event.EventListeners.initializeListeners(EventListeners.java:205)
 at org.hibernate.cfg.Configuration.getInitializedEventListeners(Configuration.java:1338)
 at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1327)
 ...
Caused by: org.hibernate.DuplicateMappingException: duplicate import: MIDDLE refers to both MIDDLE and br.com.touchtec.versionPoc.Middle (try using auto-import="false")

Using both annotations together brings up the same stack trace. Apparently, Envers is trying to generate a MIDDLE table because I declared it on the @AuditJoinTable annotation, but it gives up when it finds that the entity MIDDLE already exists (since I declared it on persistence.xml). However, I wanted Envers to use my entity as join table.

Is it possible to do what I want? Am I missing something?

Thanks again,
Marcus

[adamw]

Hello,

your first mapping looks fine. There is a test in Envers that is almost identical - and it passes. Can you maybe post a full example? Along with your configuration etc.

As for the second example, I think the mapping is wrong. Either you declare the middle entity as a "JPA entity", and then the relation from Entity1 must go to Middle (so Entity1 must have a list of Middle). Or you just do a uni-directional relation to Entity2.

Adam