Hibernate version:
16:42:40,695 INFO Version:15 - Hibernate EntityManager 3.2.0.CR2
16:42:40,742 INFO Version:15 - Hibernate Annotations 3.2.0.CR2
16:42:40,773 INFO Environment:500 - Hibernate 3.2 cr4


I am trying to attempt optimistic locking with the EntityManager.

When the EntityManager detects a change, it is throwing the following stacktrace:

Exception in thread "main" java.lang.IllegalArgumentException: id to load is required for loading
at org.hibernate.event.LoadEvent.<init>(LoadEvent.java:51)
at org.hibernate.event.LoadEvent.<init>(LoadEvent.java:33)
at org.hibernate.impl.SessionImpl.load(SessionImpl.java:792)
at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:601)
at org.hibernate.ejb.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:236)

If I change the code to use a SessionFactory and session instead of using EntityManager it works correctly.

I am configuring the EntityManager with the following code:
Ejb3Configuration cfg = new Ejb3Configuration();


EntityManagerFactory emf =
cfg.configure("com/hibernate/test/hibernate.cfg.xml")
.buildEntityManagerFactory();


My code to persist the changes is:
private static void updateUser(EntityManagerFactory enf, HibernateUser user)
{
EntityManager em = enf.createEntityManager();
EntityTransaction t = em.getTransaction();


try {
t.begin();
try
{
em.merge(user);
t.commit();
}
catch (RuntimeException re)
{
t.rollback();
throw re;
}
}
finally
{
em.close();
}
}


My simple hello world class is
package com.hibernate.test;

import javax.persistence.Basic;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Version;



@javax.persistence.SequenceGenerator(
name="SEQ_GEN",
sequenceName="BATCHID_SEQ",
allocationSize=1
)

@Entity
@Table(name="Hibernate")
public class HibernateUser
{
private Long id;
private String name;
private Long version;

public HibernateUser()
{
super();
}

@Id @GeneratedValue(strategy=GenerationType.SEQUENCE, generator="SEQ_GEN")
public Long getId()
{
return id;
}
public void setId(Long id)
{
this.id = id;
}

@Basic
public String getName()
{
return name;
}

public void setName(String name)
{
this.name = name;
}

@Version
public Long getVersion()
{
return version;
}
public void setVersion(Long version)
{
this.version = version;
}



}

Do I have something configured wrong?

it should work, you probably have some weird mistake somewhere

I can't find anything wrong with my configuration. Could this possibly be a bug? The reason I ask is because it looks the EntityManager is catching
the concurrent modification because it is about to throw a PersistenceException. However, it looks like its creating a LoadEvent and passing in a null Id to the LoadEvent constructor which is what throws the exception.


at org.hibernate.event.LoadEvent.<init>(LoadEvent.java:51)
at org.hibernate.event.LoadEvent.<init>(LoadEvent.java:33)
at org.hibernate.impl.SessionImpl.load(SessionImpl.java:792)
at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:601)
at org.hibernate.ejb.AbstractEntityManagerImpl.merge(AbstractEntityManagerImpl.java:236)

Ah got it.
http://opensource.atlassian.com/projects/hibernate/browse/EJB-231

The original exception is an optimistic locking exception, I swallow it by mistake

Thanks