Does Spring support PersistenceContextType.EXTENDED?

A @Stateful EJB can use Persist开发者_如何学运维enceContextType.EXTENDED for reusing the same EntityManager across multiple transactions. This is useful in implementing conversational scopes. Does Spring have any support for this?

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There is a short discussion of this in Implementing DAOs based on plain JPA:

The @PersistenceContext annotation has an optional attribute type, which defaults to PersistenceContextType.TRANSACTION. This default is what you need to receive a shared EntityManager proxy. The alternative, PersistenceContextType.EXTENDED, is a completely different affair: This results in a so-called extended EntityManager, which is not thread-safe and hence must not be used in a concurrently accessed component such as a Spring-managed singleton bean. Extended EntityManagers are only supposed to be used in stateful components that, for example, reside in a session, with the lifecycle of the EntityManager not tied to a current transaction but rather being completely up to the application.

So no, it doesn't sound like Spring supports them.

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Yes, Spring supports it. See, for example, Injection of PersistenceContext with PersistenceContextType EXTENDED.

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Spring has a special class with static factory methods for creation of extended entity managers. See ExtendedEntityManagerCreator

Also, if you inject an EntityManagerFactory and invoke createEntityManager(SynchronizationType.SYNCHRONIZED) it will create the entity manager with extended persistence context (it will not automatically detach entities after commit of transaction).