Get a list of managed Entity instances in a persistence context

hibernate, hibernate-4.x, jpa

Solution

JPA does not define such a capability. But you can do it using Hibernate calls:

final org.hibernate.engine.spi.SessionImplementor session = em.unwrap( org.hibernate.engine.spi.SessionImplementor.class );
final org.hibernate.engine.spi.PersistenceContext pc = session.getPersistenceContext();
final Map.Entry<Object,org.hibernate.engine.spi.EntityEntry>[] entityEntries = pc.reentrantSafeEntityEntries();

`entityEntries` here is an array of Map.Entry instances whose "key" is the entity itself and whose value is an instance of `org.hibernate.engine.spi.EntityEntry` that describes various info about the entity, including information like EntityEntry.getStatus().

Problem

Is there a way to obtain a list of "known" Entity instances for a given Session/EntityManager in JPA/Hibernate 4.x? By "known" I mean either loaded, created or changed, i.e. a managed entity that exists in a persistence context. I know of `EntityManager#contains` method so I'm guessing that such a list is maintained, but how can I get to it? EDIT: Also, how can I query the state of the persistent entity (check if it is created, updated, deleted or clean in this persistence context)?

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