Is there a way to get all managed entities from an EntityManager

I'm setting up a basic test data util and want to keep track of all the data that the EntityManager handles. Rather than just having a bunch of lists for each entity is there a way to grab everything being managed by the EntityManager in one fell swoop?

So instead of this:

EntityManager em;
List<Entity1> a;
List<Entity2> b;
...
List<Entit开发者_如何学JAVAyn> n;

cleanup() {
    for(Entity1 e : a) em.remove(e);
    for(Entity2 f : b) em.remove(f);
    ...
    for(Entityn z : n) em.remove(z);
}

I want something like this;

EntityManager em;

cleanup() {
    List<Object> allEntities = em.getAllManagedEntities(); //<-this doesnt exist
    for(Object o : allEntities) em.remove(o);
}

Not sure if this is possible, but I just would image that the manager knows what it is managing? Or, if you have any ideas of managing a bunch of entities easily.

I think this might help:

for (EntityType<?> entity : entityManager.getMetamodel().getEntities()) {
    final String className = entity.getName();
    log.debug("Trying select * from: " + className);
    Query q = entityManager.createQuery("from " + className + " c");
    q.getResultList().iterator();
    log.debug("ok: " + className);
}

Basically EntityManager::MetaModel contains the MetaData information regarding the Entities managed.

What JPA provider are you using?

There is nothing in the JPA API for this.

If using EclipseLink, you can use,

em.unwrap(UnitOfWorkImpl.class).getCloneMapping().keySet()

If you need to remove all entities inserted during a test, you can execute the test inside a transaction and then rollback that transaction. See 9.3.5.4 Transaction management as an example of this approach.