What is the difference between Transaction-scoped Persistence context and Extended Persistence context ??

Question

What is the difference between Transaction-scoped Persistence context and Extended Persistence context ??

Answer 1

The difference is clearly explained in the JSR-220 Enterprise JavaBeans 3.0 specification:

5.6 Container-managed Persistence Contexts

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A container-managed persistence context may be defined to have either a lifetime that is scoped to a single transaction or an extended lifetime that spans multiple transactions, depending on the PersistenceContextType that is specified when its EntityManager is created. This specification refers to such persistence contexts as transaction-scoped persistence contexts and extended persistence contexts respectively.

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5.6.1 Container-managed Transaction-scoped Persistence Context

The application may obtain a container-managed entity manager with transaction-scoped persistence context bound to the JTA transaction by injection or direct lookup in the JNDI namespace. The persistence context type for the entity manager is defaulted or defined as PersistenceContextType.TRANSACTION.

A new persistence context begins when the container-managed entity manager is invoked^[36] in the scope of an active JTA transaction, and there is no current persistence context already associated with the JTA transaction. The persistence context is created and then associated with the JTA transaction.

The persistence context ends when the associated JTA transaction commits or rolls back, and all entities that were managed by the EntityManager become detached.

If the entity manager is invoked outside the scope of a transaction, any entities loaded from the database will immediately become detached at the end of the method call.

5.6.2 Container-managed Extended Persistence Context

A container-managed extended persistence context can only be initiated within the scope of a stateful session bean. It exists from the point at which the stateful session bean that declares a dependency on an entity manager of type PersistenceContextType.EXTENDED is created, and is said to be bound to the stateful session bean. The dependency on the extended persistence context is declared by means of the PersistenceContext annotation or persistence-context-ref deployment descriptor element.

The persistence context is closed by the container when the @Remove method of the stateful session bean completes (or the stateful session bean instance is otherwise destroyed).

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