Merge a removed entity bean

[sebciar]

Hello,

I've a problem concerning merge entity bean (EJB3).
I use a session bean stateless with transactions that is able to create, update and remove an entity bean.
I've created a java client application that uses my session bean.

@TransactionAttribute(value=TransactionAttributeType.REQUIRES_NEW)
public void save(Object obj){
 em.merge(obj);
 }

@TransactionAttribute(TransactionAttributeType.REQUIRED)
public void removeAccessControl(Object obj) throws SecurityException{
 AccessControl access=null;
 access=em.find(AccessControl.class,accessControlid);

 //Remove dependecies
 em.remove(access);
 }

I run two instances of my client to simulate two users actions. The first one tries to remove the the entity #1 and the second client tries to rename same data row(#1).The Remove action is run just before the update.
The remove action deletes my bean in my database. But I was expecting that my update will fail (I use me.merge(obj)). NO! The row is added with a new ID: #2.
All entity object passed in parameters in my methods are detached.

Is that behavior normal? Is it possible, in my case, to make the entity manager automatically crache when I try to merge an entity which has been deleted by another thread without making a database check in my code ?

I tried the following code in my session bean :

public void test(){
 em.remove(entity);
 /*....*/
 em.merge(entity);
}

Here an exception is thrown that informs me that entity manager cannot merge a deleted entity. I would like to have the same behavior between 2 different transactions and 2 different threads...

Thank fo all help answers.