https://github.com/spring-projects/spring-framework: Spring Object/Relational Mapping (Spring IO)
  • Juergen Hoeller 
/*
 * Copyright 2002-2020 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.orm.jpa;

import java.util.Map;

import javax.persistence.EntityExistsException;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityNotFoundException;
import javax.persistence.LockTimeoutException;
import javax.persistence.NoResultException;
import javax.persistence.NonUniqueResultException;
import javax.persistence.OptimisticLockException;
import javax.persistence.PersistenceException;
import javax.persistence.PessimisticLockException;
import javax.persistence.Query;
import javax.persistence.QueryTimeoutException;
import javax.persistence.SynchronizationType;
import javax.persistence.TransactionRequiredException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.core.Ordered;
import org.springframework.dao.CannotAcquireLockException;
import org.springframework.dao.DataAccessException;
import org.springframework.dao.DataAccessResourceFailureException;
import org.springframework.dao.DataIntegrityViolationException;
import org.springframework.dao.EmptyResultDataAccessException;
import org.springframework.dao.IncorrectResultSizeDataAccessException;
import org.springframework.dao.InvalidDataAccessApiUsageException;
import org.springframework.dao.PessimisticLockingFailureException;
import org.springframework.jdbc.datasource.DataSourceUtils;
import org.springframework.lang.Nullable;
import org.springframework.transaction.support.ResourceHolderSynchronization;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.util.Assert;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StringUtils;


Helper class featuring methods for JPA EntityManager handling,
allowing for reuse of EntityManager instances within transactions.
Also provides support for exception translation.

Mainly intended for internal use within the framework.

Author:Juergen Hoeller
Since:2.0
/**
 * Helper class featuring methods for JPA EntityManager handling,
 * allowing for reuse of EntityManager instances within transactions.
 * Also provides support for exception translation.
 *
 * <p>Mainly intended for internal use within the framework.
 *
 * @author Juergen Hoeller
 * @since 2.0
 */
public abstract class EntityManagerFactoryUtils {

	
Order value for TransactionSynchronization objects that clean up JPA
EntityManagers. Return DataSourceUtils.CONNECTION_SYNCHRONIZATION_ORDER - 100
to execute EntityManager cleanup before JDBC Connection cleanup, if any.

See Also:
  • CONNECTION_SYNCHRONIZATION_ORDER.CONNECTION_SYNCHRONIZATION_ORDER
/**
	 * Order value for TransactionSynchronization objects that clean up JPA
	 * EntityManagers. Return DataSourceUtils.CONNECTION_SYNCHRONIZATION_ORDER - 100
	 * to execute EntityManager cleanup before JDBC Connection cleanup, if any.
	 * @see org.springframework.jdbc.datasource.DataSourceUtils#CONNECTION_SYNCHRONIZATION_ORDER
	 */
	public static final int ENTITY_MANAGER_SYNCHRONIZATION_ORDER =
			DataSourceUtils.CONNECTION_SYNCHRONIZATION_ORDER - 100;

	private static final Log logger = LogFactory.getLog(EntityManagerFactoryUtils.class);


	
Find an EntityManagerFactory with the given name in the given
Spring application context (represented as ListableBeanFactory).

The specified unit name will be matched against the configured persistence unit, provided that a discovered EntityManagerFactory implements the EntityManagerFactoryInfo interface. If not, the persistence unit name will be matched against the Spring bean name, assuming that the EntityManagerFactory bean names follow that convention. 
If no unit name has been given, this method will search for a default EntityManagerFactory through BeanFactory.getBean(Class<Object>). 
Params:
  • beanFactory – the ListableBeanFactory to search
  • unitName – the name of the persistence unit (may be null or empty, in which case a single bean of type EntityManagerFactory will be searched for)
Throws:
See Also:
Returns:the EntityManagerFactory
/**
	 * Find an EntityManagerFactory with the given name in the given
	 * Spring application context (represented as ListableBeanFactory).
	 * <p>The specified unit name will be matched against the configured
	 * persistence unit, provided that a discovered EntityManagerFactory
	 * implements the {@link EntityManagerFactoryInfo} interface. If not,
	 * the persistence unit name will be matched against the Spring bean name,
	 * assuming that the EntityManagerFactory bean names follow that convention.
	 * <p>If no unit name has been given, this method will search for a default
	 * EntityManagerFactory through {@link ListableBeanFactory#getBean(Class)}.
	 * @param beanFactory the ListableBeanFactory to search
	 * @param unitName the name of the persistence unit (may be {@code null} or empty,
	 * in which case a single bean of type EntityManagerFactory will be searched for)
	 * @return the EntityManagerFactory
	 * @throws NoSuchBeanDefinitionException if there is no such EntityManagerFactory in the context
	 * @see EntityManagerFactoryInfo#getPersistenceUnitName()
	 */
	public static EntityManagerFactory findEntityManagerFactory(
			ListableBeanFactory beanFactory, @Nullable String unitName) throws NoSuchBeanDefinitionException {

		Assert.notNull(beanFactory, "ListableBeanFactory must not be null");
		if (StringUtils.hasLength(unitName)) {
			// See whether we can find an EntityManagerFactory with matching persistence unit name.
			String[] candidateNames =
					BeanFactoryUtils.beanNamesForTypeIncludingAncestors(beanFactory, EntityManagerFactory.class);
			for (String candidateName : candidateNames) {
				EntityManagerFactory emf = (EntityManagerFactory) beanFactory.getBean(candidateName);
				if (emf instanceof EntityManagerFactoryInfo &&
						unitName.equals(((EntityManagerFactoryInfo) emf).getPersistenceUnitName())) {
					return emf;
				}
			}
			// No matching persistence unit found - simply take the EntityManagerFactory
			// with the persistence unit name as bean name (by convention).
			return beanFactory.getBean(unitName, EntityManagerFactory.class);
		}
		else {
			// Find unique EntityManagerFactory bean in the context, falling back to parent contexts.
			return beanFactory.getBean(EntityManagerFactory.class);
		}
	}

	
Obtain a JPA EntityManager from the given factory. Is aware of a corresponding
EntityManager bound to the current thread, e.g. when using JpaTransactionManager.

Note: Will return null if no thread-bound EntityManager found! 
Params:
  • emf – the EntityManagerFactory to create the EntityManager with
Throws:
See Also:
Returns:the EntityManager, or null if none found
/**
	 * Obtain a JPA EntityManager from the given factory. Is aware of a corresponding
	 * EntityManager bound to the current thread, e.g. when using JpaTransactionManager.
	 * <p>Note: Will return {@code null} if no thread-bound EntityManager found!
	 * @param emf the EntityManagerFactory to create the EntityManager with
	 * @return the EntityManager, or {@code null} if none found
	 * @throws DataAccessResourceFailureException if the EntityManager couldn't be obtained
	 * @see JpaTransactionManager
	 */
	@Nullable
	public static EntityManager getTransactionalEntityManager(EntityManagerFactory emf)
			throws DataAccessResourceFailureException {

		return getTransactionalEntityManager(emf, null);
	}

	
Obtain a JPA EntityManager from the given factory. Is aware of a corresponding
EntityManager bound to the current thread, e.g. when using JpaTransactionManager.

Note: Will return null if no thread-bound EntityManager found! 
Params:
  • emf – the EntityManagerFactory to create the EntityManager with
  • properties – the properties to be passed into the createEntityManager call (may be null)
Throws:
See Also:
Returns:the EntityManager, or null if none found
/**
	 * Obtain a JPA EntityManager from the given factory. Is aware of a corresponding
	 * EntityManager bound to the current thread, e.g. when using JpaTransactionManager.
	 * <p>Note: Will return {@code null} if no thread-bound EntityManager found!
	 * @param emf the EntityManagerFactory to create the EntityManager with
	 * @param properties the properties to be passed into the {@code createEntityManager}
	 * call (may be {@code null})
	 * @return the EntityManager, or {@code null} if none found
	 * @throws DataAccessResourceFailureException if the EntityManager couldn't be obtained
	 * @see JpaTransactionManager
	 */
	@Nullable
	public static EntityManager getTransactionalEntityManager(EntityManagerFactory emf, @Nullable Map<?, ?> properties)
			throws DataAccessResourceFailureException {
		try {
			return doGetTransactionalEntityManager(emf, properties, true);
		}
		catch (PersistenceException ex) {
			throw new DataAccessResourceFailureException("Could not obtain JPA EntityManager", ex);
		}
	}

	
Obtain a JPA EntityManager from the given factory. Is aware of a corresponding
EntityManager bound to the current thread, e.g. when using JpaTransactionManager.

Same as getEntityManager, but throwing the original PersistenceException. 
Params:
  • emf – the EntityManagerFactory to create the EntityManager with
  • properties – the properties to be passed into the createEntityManager call (may be null)
Throws:
  • PersistenceException – if the EntityManager couldn't be created
See Also:
Returns:the EntityManager, or null if none found
/**
	 * Obtain a JPA EntityManager from the given factory. Is aware of a corresponding
	 * EntityManager bound to the current thread, e.g. when using JpaTransactionManager.
	 * <p>Same as {@code getEntityManager}, but throwing the original PersistenceException.
	 * @param emf the EntityManagerFactory to create the EntityManager with
	 * @param properties the properties to be passed into the {@code createEntityManager}
	 * call (may be {@code null})
	 * @return the EntityManager, or {@code null} if none found
	 * @throws javax.persistence.PersistenceException if the EntityManager couldn't be created
	 * @see #getTransactionalEntityManager(javax.persistence.EntityManagerFactory)
	 * @see JpaTransactionManager
	 */
	@Nullable
	public static EntityManager doGetTransactionalEntityManager(EntityManagerFactory emf, Map<?, ?> properties)
			throws PersistenceException {

		return doGetTransactionalEntityManager(emf, properties, true);
	}

	
Obtain a JPA EntityManager from the given factory. Is aware of a corresponding
EntityManager bound to the current thread, e.g. when using JpaTransactionManager.

Same as getEntityManager, but throwing the original PersistenceException. 
Params:
  • emf – the EntityManagerFactory to create the EntityManager with
  • properties – the properties to be passed into the createEntityManager call (may be null)
  • synchronizedWithTransaction – whether to automatically join ongoing
transactions (according to the JPA 2.1 SynchronizationType rules)
Throws:
  • PersistenceException – if the EntityManager couldn't be created
See Also:
Returns:the EntityManager, or null if none found
/**
	 * Obtain a JPA EntityManager from the given factory. Is aware of a corresponding
	 * EntityManager bound to the current thread, e.g. when using JpaTransactionManager.
	 * <p>Same as {@code getEntityManager}, but throwing the original PersistenceException.
	 * @param emf the EntityManagerFactory to create the EntityManager with
	 * @param properties the properties to be passed into the {@code createEntityManager}
	 * call (may be {@code null})
	 * @param synchronizedWithTransaction whether to automatically join ongoing
	 * transactions (according to the JPA 2.1 SynchronizationType rules)
	 * @return the EntityManager, or {@code null} if none found
	 * @throws javax.persistence.PersistenceException if the EntityManager couldn't be created
	 * @see #getTransactionalEntityManager(javax.persistence.EntityManagerFactory)
	 * @see JpaTransactionManager
	 */
	@Nullable
	public static EntityManager doGetTransactionalEntityManager(
			EntityManagerFactory emf, @Nullable Map<?, ?> properties, boolean synchronizedWithTransaction)
			throws PersistenceException {

		Assert.notNull(emf, "No EntityManagerFactory specified");

		EntityManagerHolder emHolder =
				(EntityManagerHolder) TransactionSynchronizationManager.getResource(emf);
		if (emHolder != null) {
			if (synchronizedWithTransaction) {
				if (!emHolder.isSynchronizedWithTransaction()) {
					if (TransactionSynchronizationManager.isActualTransactionActive()) {
						// Try to explicitly synchronize the EntityManager itself
						// with an ongoing JTA transaction, if any.
						try {
							emHolder.getEntityManager().joinTransaction();
						}
						catch (TransactionRequiredException ex) {
							logger.debug("Could not join transaction because none was actually active", ex);
						}
					}
					if (TransactionSynchronizationManager.isSynchronizationActive()) {
						Object transactionData = prepareTransaction(emHolder.getEntityManager(), emf);
						TransactionSynchronizationManager.registerSynchronization(
								new TransactionalEntityManagerSynchronization(emHolder, emf, transactionData, false));
						emHolder.setSynchronizedWithTransaction(true);
					}
				}
				// Use holder's reference count to track synchronizedWithTransaction access.
				// isOpen() check used below to find out about it.
				emHolder.requested();
				return emHolder.getEntityManager();
			}
			else {
				// unsynchronized EntityManager demanded
				if (emHolder.isTransactionActive() && !emHolder.isOpen()) {
					if (!TransactionSynchronizationManager.isSynchronizationActive()) {
						return null;
					}
					// EntityManagerHolder with an active transaction coming from JpaTransactionManager,
					// with no synchronized EntityManager having been requested by application code before.
					// Unbind in order to register a new unsynchronized EntityManager instead.
					TransactionSynchronizationManager.unbindResource(emf);
				}
				else {
					// Either a previously bound unsynchronized EntityManager, or the application
					// has requested a synchronized EntityManager before and therefore upgraded
					// this transaction's EntityManager to synchronized before.
					return emHolder.getEntityManager();
				}
			}
		}
		else if (!TransactionSynchronizationManager.isSynchronizationActive()) {
			// Indicate that we can't obtain a transactional EntityManager.
			return null;
		}

		// Create a new EntityManager for use within the current transaction.
		logger.debug("Opening JPA EntityManager");
		EntityManager em = null;
		if (!synchronizedWithTransaction) {
			try {
				em = emf.createEntityManager(SynchronizationType.UNSYNCHRONIZED, properties);
			}
			catch (AbstractMethodError err) {
				// JPA 2.1 API available but method not actually implemented in persistence provider:
				// falling back to regular createEntityManager method.
			}
		}
		if (em == null) {
			em = (!CollectionUtils.isEmpty(properties) ? emf.createEntityManager(properties) : emf.createEntityManager());
		}

		try {
			// Use same EntityManager for further JPA operations within the transaction.
			// Thread-bound object will get removed by synchronization at transaction completion.
			emHolder = new EntityManagerHolder(em);
			if (synchronizedWithTransaction) {
				Object transactionData = prepareTransaction(em, emf);
				TransactionSynchronizationManager.registerSynchronization(
						new TransactionalEntityManagerSynchronization(emHolder, emf, transactionData, true));
				emHolder.setSynchronizedWithTransaction(true);
			}
			else {
				// Unsynchronized - just scope it for the transaction, as demanded by the JPA 2.1 spec...
				TransactionSynchronizationManager.registerSynchronization(
						new TransactionScopedEntityManagerSynchronization(emHolder, emf));
			}
			TransactionSynchronizationManager.bindResource(emf, emHolder);
		}
		catch (RuntimeException ex) {
			// Unexpected exception from external delegation call -> close EntityManager and rethrow.
			closeEntityManager(em);
			throw ex;
		}

		return em;
	}

	
Prepare a transaction on the given EntityManager, if possible.

Params:
  • em – the EntityManager to prepare
  • emf – the EntityManagerFactory that the EntityManager has been created with
See Also:
  • JpaDialect.prepareTransaction
Returns:an arbitrary object that holds transaction data, if any
(to be passed into cleanupTransaction)
/**
	 * Prepare a transaction on the given EntityManager, if possible.
	 * @param em the EntityManager to prepare
	 * @param emf the EntityManagerFactory that the EntityManager has been created with
	 * @return an arbitrary object that holds transaction data, if any
	 * (to be passed into cleanupTransaction)
	 * @see JpaDialect#prepareTransaction
	 */
	@Nullable
	private static Object prepareTransaction(EntityManager em, EntityManagerFactory emf) {
		if (emf instanceof EntityManagerFactoryInfo) {
			EntityManagerFactoryInfo emfInfo = (EntityManagerFactoryInfo) emf;
			JpaDialect jpaDialect = emfInfo.getJpaDialect();
			if (jpaDialect != null) {
				return jpaDialect.prepareTransaction(em,
						TransactionSynchronizationManager.isCurrentTransactionReadOnly(),
						TransactionSynchronizationManager.getCurrentTransactionName());
			}
		}
		return null;
	}

	
Prepare a transaction on the given EntityManager, if possible.

Params:
  • transactionData – arbitrary object that holds transaction data, if any
(as returned by prepareTransaction)
  • emf – the EntityManagerFactory that the EntityManager has been created with
See Also:
/**
	 * Prepare a transaction on the given EntityManager, if possible.
	 * @param transactionData arbitrary object that holds transaction data, if any
	 * (as returned by prepareTransaction)
	 * @param emf the EntityManagerFactory that the EntityManager has been created with
	 * @see JpaDialect#cleanupTransaction
	 */
	private static void cleanupTransaction(@Nullable Object transactionData, EntityManagerFactory emf) {
		if (emf instanceof EntityManagerFactoryInfo) {
			EntityManagerFactoryInfo emfInfo = (EntityManagerFactoryInfo) emf;
			JpaDialect jpaDialect = emfInfo.getJpaDialect();
			if (jpaDialect != null) {
				jpaDialect.cleanupTransaction(transactionData);
			}
		}
	}

	
Apply the current transaction timeout, if any, to the given JPA Query object.

This method sets the JPA 2.0 query hint "javax.persistence.query.timeout" accordingly.

Params:
  • query – the JPA Query object
  • emf – the JPA EntityManagerFactory that the Query was created for
/**
	 * Apply the current transaction timeout, if any, to the given JPA Query object.
	 * <p>This method sets the JPA 2.0 query hint "javax.persistence.query.timeout" accordingly.
	 * @param query the JPA Query object
	 * @param emf the JPA EntityManagerFactory that the Query was created for
	 */
	public static void applyTransactionTimeout(Query query, EntityManagerFactory emf) {
		EntityManagerHolder emHolder = (EntityManagerHolder) TransactionSynchronizationManager.getResource(emf);
		if (emHolder != null && emHolder.hasTimeout()) {
			int timeoutValue = (int) emHolder.getTimeToLiveInMillis();
			try {
				query.setHint("javax.persistence.query.timeout", timeoutValue);
			}
			catch (IllegalArgumentException ex) {
				// oh well, at least we tried...
			}
		}
	}

	
Convert the given runtime exception to an appropriate exception from the org.springframework.dao hierarchy. Return null if no translation is appropriate: any other exception may have resulted from user code, and should not be translated. 
The most important cases like object not found or optimistic locking failure
are covered here. For more fine-granular conversion, JpaTransactionManager etc
support sophisticated translation of exceptions via a JpaDialect.

Params:
  • ex – runtime exception that occurred
Returns:the corresponding DataAccessException instance, or null if the exception should not be translated
/**
	 * Convert the given runtime exception to an appropriate exception from the
	 * {@code org.springframework.dao} hierarchy.
	 * Return null if no translation is appropriate: any other exception may
	 * have resulted from user code, and should not be translated.
	 * <p>The most important cases like object not found or optimistic locking failure
	 * are covered here. For more fine-granular conversion, JpaTransactionManager etc
	 * support sophisticated translation of exceptions via a JpaDialect.
	 * @param ex runtime exception that occurred
	 * @return the corresponding DataAccessException instance,
	 * or {@code null} if the exception should not be translated
	 */
	@Nullable
	public static DataAccessException convertJpaAccessExceptionIfPossible(RuntimeException ex) {
		// Following the JPA specification, a persistence provider can also
		// throw these two exceptions, besides PersistenceException.
		if (ex instanceof IllegalStateException) {
			return new InvalidDataAccessApiUsageException(ex.getMessage(), ex);
		}
		if (ex instanceof IllegalArgumentException) {
			return new InvalidDataAccessApiUsageException(ex.getMessage(), ex);
		}

		// Check for well-known PersistenceException subclasses.
		if (ex instanceof EntityNotFoundException) {
			return new JpaObjectRetrievalFailureException((EntityNotFoundException) ex);
		}
		if (ex instanceof NoResultException) {
			return new EmptyResultDataAccessException(ex.getMessage(), 1, ex);
		}
		if (ex instanceof NonUniqueResultException) {
			return new IncorrectResultSizeDataAccessException(ex.getMessage(), 1, ex);
		}
		if (ex instanceof QueryTimeoutException) {
			return new org.springframework.dao.QueryTimeoutException(ex.getMessage(), ex);
		}
		if (ex instanceof LockTimeoutException) {
			return new CannotAcquireLockException(ex.getMessage(), ex);
		}
		if (ex instanceof PessimisticLockException) {
			return new PessimisticLockingFailureException(ex.getMessage(), ex);
		}
		if (ex instanceof OptimisticLockException) {
			return new JpaOptimisticLockingFailureException((OptimisticLockException) ex);
		}
		if (ex instanceof EntityExistsException) {
			return new DataIntegrityViolationException(ex.getMessage(), ex);
		}
		if (ex instanceof TransactionRequiredException) {
			return new InvalidDataAccessApiUsageException(ex.getMessage(), ex);
		}

		// If we have another kind of PersistenceException, throw it.
		if (ex instanceof PersistenceException) {
			return new JpaSystemException(ex);
		}

		// If we get here, we have an exception that resulted from user code,
		// rather than the persistence provider, so we return null to indicate
		// that translation should not occur.
		return null;
	}

	
Close the given JPA EntityManager,
catching and logging any cleanup exceptions thrown.

Params:
  • em – the JPA EntityManager to close (may be null)
See Also:
  • close.close()
/**
	 * Close the given JPA EntityManager,
	 * catching and logging any cleanup exceptions thrown.
	 * @param em the JPA EntityManager to close (may be {@code null})
	 * @see javax.persistence.EntityManager#close()
	 */
	public static void closeEntityManager(@Nullable EntityManager em) {
		if (em != null) {
			try {
				if (em.isOpen()) {
					em.close();
				}
			}
			catch (Throwable ex) {
				logger.error("Failed to release JPA EntityManager", ex);
			}
		}
	}


	
Callback for resource cleanup at the end of a non-JPA transaction
(e.g. when participating in a JtaTransactionManager transaction),
fully synchronized with the ongoing transaction.

See Also:
  • JtaTransactionManager
/**
	 * Callback for resource cleanup at the end of a non-JPA transaction
	 * (e.g. when participating in a JtaTransactionManager transaction),
	 * fully synchronized with the ongoing transaction.
	 * @see org.springframework.transaction.jta.JtaTransactionManager
	 */
	private static class TransactionalEntityManagerSynchronization
			extends ResourceHolderSynchronization<EntityManagerHolder, EntityManagerFactory>
			implements Ordered {

		@Nullable
		private final Object transactionData;

		@Nullable
		private final JpaDialect jpaDialect;

		private final boolean newEntityManager;

		public TransactionalEntityManagerSynchronization(
				EntityManagerHolder emHolder, EntityManagerFactory emf, @Nullable Object txData, boolean newEm) {

			super(emHolder, emf);
			this.transactionData = txData;
			this.jpaDialect = (emf instanceof EntityManagerFactoryInfo ?
					((EntityManagerFactoryInfo) emf).getJpaDialect() : null);
			this.newEntityManager = newEm;
		}

		@Override
		public int getOrder() {
			return ENTITY_MANAGER_SYNCHRONIZATION_ORDER;
		}

		@Override
		protected void flushResource(EntityManagerHolder resourceHolder) {
			EntityManager em = resourceHolder.getEntityManager();
			if (em instanceof EntityManagerProxy) {
				EntityManager target = ((EntityManagerProxy) em).getTargetEntityManager();
				if (TransactionSynchronizationManager.hasResource(target)) {
					// ExtendedEntityManagerSynchronization active after joinTransaction() call:
					// flush synchronization already registered.
					return;
				}
			}
			try {
				em.flush();
			}
			catch (RuntimeException ex) {
				DataAccessException dae;
				if (this.jpaDialect != null) {
					dae = this.jpaDialect.translateExceptionIfPossible(ex);
				}
				else {
					dae = convertJpaAccessExceptionIfPossible(ex);
				}
				throw (dae != null ? dae : ex);
			}
		}

		@Override
		protected boolean shouldUnbindAtCompletion() {
			return this.newEntityManager;
		}

		@Override
		protected void releaseResource(EntityManagerHolder resourceHolder, EntityManagerFactory resourceKey) {
			closeEntityManager(resourceHolder.getEntityManager());
		}

		@Override
		protected void cleanupResource(
				EntityManagerHolder resourceHolder, EntityManagerFactory resourceKey, boolean committed) {

			if (!committed) {
				// Clear all pending inserts/updates/deletes in the EntityManager.
				// Necessary for pre-bound EntityManagers, to avoid inconsistent state.
				resourceHolder.getEntityManager().clear();
			}
			cleanupTransaction(this.transactionData, resourceKey);
		}
	}


	
Minimal callback that just closes the EntityManager at the end of the transaction.

/**
	 * Minimal callback that just closes the EntityManager at the end of the transaction.
	 */
	private static class TransactionScopedEntityManagerSynchronization
			extends ResourceHolderSynchronization<EntityManagerHolder, EntityManagerFactory>
			implements Ordered {

		public TransactionScopedEntityManagerSynchronization(EntityManagerHolder emHolder, EntityManagerFactory emf) {
			super(emHolder, emf);
		}

		@Override
		public int getOrder() {
			return ENTITY_MANAGER_SYNCHRONIZATION_ORDER + 1;
		}

		@Override
		protected void releaseResource(EntityManagerHolder resourceHolder, EntityManagerFactory resourceKey) {
			closeEntityManager(resourceHolder.getEntityManager());
		}
	}

}