org.apache.openejb.persistence
Class JtaEntityManagerRegistry

java.lang.Object
  org.apache.openejb.persistence.JtaEntityManagerRegistry

public class JtaEntityManagerRegistry
extends Object

The JtaEntityManagerRegistry tracks JTA entity managers for transaction and extended scoped entity managers. A single instance of this object should be created and shared by all JtaEntityManagers in the server instance. Failure to do this will result in multiple entity managers being created for a single persistence until, and that will result in cache incoherence.

Nested Class Summary

static class

JtaEntityManagerRegistry.EntityManagerTracker This object is used track all EntityManagers inherited in order to effectively close it when the latest Extended persistence context is no more accessed.

Constructor Summary

JtaEntityManagerRegistry(TransactionSynchronizationRegistry transactionSynchronizationRegistry)
Creates a JtaEntityManagerRegistry using the specified transactionSynchronizationRegistry for the registry if transaction associated entity managers.

Method Summary

void	addEntityManagers(String deploymentId, Object primaryKey, Map<javax.persistence.EntityManagerFactory,JtaEntityManagerRegistry.EntityManagerTracker> entityManagers) Adds the entity managers for the specified component to the registry.
javax.persistence.EntityManager	getEntityManager(javax.persistence.EntityManagerFactory entityManagerFactory, Map properties, boolean extended, String unitName) Gets an entity manager instance from the transaction registry, extended registry or for a transaction scoped entity manager, creates a new one when an existing instance is not found.
JtaEntityManagerRegistry.EntityManagerTracker	getInheritedEntityManager(javax.persistence.EntityManagerFactory entityManagerFactory) Gets an exiting extended entity manager created by a component down the call stack.
boolean	isTransactionActive() Is a transaction active?
Map<javax.persistence.EntityManagerFactory,JtaEntityManagerRegistry.EntityManagerTracker>	removeEntityManagers(String deploymentId, Object primaryKey) Removed the registered entity managers for the specified component.
void	transactionStarted(String deploymentId, Object primaryKey) Notifies the registry that a user transaction has been started or the specified component.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JtaEntityManagerRegistry

public JtaEntityManagerRegistry(TransactionSynchronizationRegistry transactionSynchronizationRegistry)

Creates a JtaEntityManagerRegistry using the specified transactionSynchronizationRegistry for the registry if transaction associated entity managers.

Method Detail

getEntityManager

public javax.persistence.EntityManager getEntityManager(javax.persistence.EntityManagerFactory entityManagerFactory,
                                                        Map properties,
                                                        boolean extended,
                                                        String unitName)
                                                 throws IllegalStateException

Gets an entity manager instance from the transaction registry, extended registry or for a transaction scoped entity manager, creates a new one when an existing instance is not found.

It is important that a component adds extended scoped entity managers to this registry when the component is entered and removes them when exited. If this registration is not performed, an IllegalStateException will be thrown when entity manger is fetched.

Parameters:

entityManagerFactory - the entity manager factory from which an entity manager is required

properties - the properties passed to the entity manager factory when an entity manager is created

extended - is the entity manager an extended context

unitName -

Returns:

the new entity manager

Throws:

IllegalStateException - if the entity manger is extended and there is not an existing entity manager instance already registered

addEntityManagers

public void addEntityManagers(String deploymentId,
                              Object primaryKey,
                              Map<javax.persistence.EntityManagerFactory,JtaEntityManagerRegistry.EntityManagerTracker> entityManagers)
                       throws EntityManagerAlreadyRegisteredException

Adds the entity managers for the specified component to the registry. This should be called when the component is entered.

Parameters:

deploymentId - the id of the component

entityManagers - the entity managers to register

Throws:

EntityManagerAlreadyRegisteredException - if an entity manager is already registered with the transaction for one of the supplied entity manager factories; for EJBs this should be caught and rethown as an EJBException

removeEntityManagers

public Map<javax.persistence.EntityManagerFactory,JtaEntityManagerRegistry.EntityManagerTracker> removeEntityManagers(String deploymentId,
                                                                                                                      Object primaryKey)

Removed the registered entity managers for the specified component.

Parameters:

deploymentId - the id of the component

Returns:

EntityManager map we are removing

getInheritedEntityManager

public JtaEntityManagerRegistry.EntityManagerTracker getInheritedEntityManager(javax.persistence.EntityManagerFactory entityManagerFactory)

Gets an exiting extended entity manager created by a component down the call stack.

Parameters:

entityManagerFactory - the entity manager factory from which an entity manager is needed

Returns:

the existing entity manager or null if one is not found

transactionStarted

public void transactionStarted(String deploymentId,
                               Object primaryKey)

Notifies the registry that a user transaction has been started or the specified component. When a transaction is started for a component with registered extended entity managers, the entity managers are enrolled in the transaction.

Parameters:

deploymentId - the id of the component

isTransactionActive

public boolean isTransactionActive()

Is a transaction active?

Returns:

true if a transaction is active; false otherwise