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<Entityn> 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.
EntityManagerFactory vs EntityManagerWhile EntityManagerFactory instances are thread-safe, EntityManager instances are not. The injected JPA EntityManager behave just like an EntityManager fetched from an application server's JNDI environment, as defined by the JPA specification.
The EntityManager API is used to create and remove persistent entity instances, to find entities by their primary key, and to query over entities. The set of entities that can be managed by a given EntityManager instance is defined by a persistence unit.
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.
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