/*
 * Copyright 2002-2018 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
 *
 *      http://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.io.IOException;
import java.io.NotSerializableException;
import java.io.ObjectInputStream;
import java.io.ObjectStreamException;
import java.io.Serializable;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.HashMap;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceException;
import javax.persistence.Query;
import javax.persistence.SynchronizationType;
import javax.persistence.spi.PersistenceProvider;
import javax.persistence.spi.PersistenceUnitInfo;
import javax.sql.DataSource;

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

import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.BeanClassLoaderAware;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.FactoryBean;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.task.AsyncTaskExecutor;
import org.springframework.dao.DataAccessException;
import org.springframework.dao.support.PersistenceExceptionTranslator;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.CollectionUtils;

Abstract FactoryBean that creates a local JPA EntityManagerFactory instance within a Spring application context. 
Encapsulates the common functionality between the different JPA bootstrap
contracts (standalone as well as container).
Implements support for standard JPA configuration conventions as well as Spring's customizable JpaVendorAdapter mechanism, and controls the EntityManagerFactory's lifecycle. 
This class also implements the PersistenceExceptionTranslator interface, as autodetected by Spring's PersistenceExceptionTranslationPostProcessor, for AOP-based translation of native exceptions to Spring DataAccessExceptions. Hence, the presence of e.g. LocalEntityManagerFactoryBean automatically enables a PersistenceExceptionTranslationPostProcessor to translate JPA exceptions. 
Author:
Juergen Hoeller, Rod Johnson
See Also:
LocalEntityManagerFactoryBean
LocalContainerEntityManagerFactoryBean
Since:
2.0/**
 * Abstract {@link org.springframework.beans.factory.FactoryBean} that creates
 * a local JPA {@link javax.persistence.EntityManagerFactory} instance within
 * a Spring application context.
 *
 * <p>Encapsulates the common functionality between the different JPA bootstrap
 * contracts (standalone as well as container).
 *
 * <p>Implements support for standard JPA configuration conventions as well as
 * Spring's customizable {@link JpaVendorAdapter} mechanism, and controls the
 * EntityManagerFactory's lifecycle.
 *
 * <p>This class also implements the
 * {@link org.springframework.dao.support.PersistenceExceptionTranslator}
 * interface, as autodetected by Spring's
 * {@link org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor},
 * for AOP-based translation of native exceptions to Spring DataAccessExceptions.
 * Hence, the presence of e.g. LocalEntityManagerFactoryBean automatically enables
 * a PersistenceExceptionTranslationPostProcessor to translate JPA exceptions.
 *
 * @author Juergen Hoeller
 * @author Rod Johnson
 * @since 2.0
 * @see LocalEntityManagerFactoryBean
 * @see LocalContainerEntityManagerFactoryBean
 */
@SuppressWarnings("serial")
public abstract class AbstractEntityManagerFactoryBean implements
		FactoryBean<EntityManagerFactory>, BeanClassLoaderAware, BeanFactoryAware, BeanNameAware,
		InitializingBean, DisposableBean, EntityManagerFactoryInfo, PersistenceExceptionTranslator, Serializable {

	
Logger available to subclasses. /** Logger available to subclasses. */
	protected final Log logger = LogFactory.getLog(getClass());

	@Nullable
	private PersistenceProvider persistenceProvider;

	@Nullable
	private String persistenceUnitName;

	private final Map<String, Object> jpaPropertyMap = new HashMap<>();

	@Nullable
	private Class<? extends EntityManagerFactory> entityManagerFactoryInterface;

	@Nullable
	private Class<? extends EntityManager> entityManagerInterface;

	@Nullable
	private JpaDialect jpaDialect;

	@Nullable
	private JpaVendorAdapter jpaVendorAdapter;

	@Nullable
	private AsyncTaskExecutor bootstrapExecutor;

	private ClassLoader beanClassLoader = getClass().getClassLoader();

	@Nullable
	private BeanFactory beanFactory;

	@Nullable
	private String beanName;

	
Raw EntityManagerFactory as returned by the PersistenceProvider. /** Raw EntityManagerFactory as returned by the PersistenceProvider. */
	@Nullable
	private EntityManagerFactory nativeEntityManagerFactory;

	
Future for lazily initializing raw target EntityManagerFactory. /** Future for lazily initializing raw target EntityManagerFactory. */
	@Nullable
	private Future<EntityManagerFactory> nativeEntityManagerFactoryFuture;

	
Exposed client-level EntityManagerFactory proxy. /** Exposed client-level EntityManagerFactory proxy. */
	@Nullable
	private EntityManagerFactory entityManagerFactory;


	
Set the PersistenceProvider implementation class to use for creating the
EntityManagerFactory. If not specified, the persistence provider will be
taken from the JpaVendorAdapter (if any) or retrieved through scanning
(as far as possible).
See Also:
getPersistenceProvider.getPersistenceProvider()
PersistenceProvider
Persistence/**
	 * Set the PersistenceProvider implementation class to use for creating the
	 * EntityManagerFactory. If not specified, the persistence provider will be
	 * taken from the JpaVendorAdapter (if any) or retrieved through scanning
	 * (as far as possible).
	 * @see JpaVendorAdapter#getPersistenceProvider()
	 * @see javax.persistence.spi.PersistenceProvider
	 * @see javax.persistence.Persistence
	 */
	public void setPersistenceProviderClass(Class<? extends PersistenceProvider> persistenceProviderClass) {
		this.persistenceProvider = BeanUtils.instantiateClass(persistenceProviderClass);
	}

	
Set the PersistenceProvider instance to use for creating the
EntityManagerFactory. If not specified, the persistence provider
will be taken from the JpaVendorAdapter (if any) or determined
by the persistence unit deployment descriptor (as far as possible).
See Also:
getPersistenceProvider.getPersistenceProvider()
PersistenceProvider
Persistence/**
	 * Set the PersistenceProvider instance to use for creating the
	 * EntityManagerFactory. If not specified, the persistence provider
	 * will be taken from the JpaVendorAdapter (if any) or determined
	 * by the persistence unit deployment descriptor (as far as possible).
	 * @see JpaVendorAdapter#getPersistenceProvider()
	 * @see javax.persistence.spi.PersistenceProvider
	 * @see javax.persistence.Persistence
	 */
	public void setPersistenceProvider(@Nullable PersistenceProvider persistenceProvider) {
		this.persistenceProvider = persistenceProvider;
	}

	@Override
	@Nullable
	public PersistenceProvider getPersistenceProvider() {
		return this.persistenceProvider;
	}

	
Specify the name of the EntityManagerFactory configuration.
Default is none, indicating the default EntityManagerFactory
configuration. The persistence provider will throw an exception if
ambiguous EntityManager configurations are found.
See Also:
createEntityManagerFactory.createEntityManagerFactory(String)/**
	 * Specify the name of the EntityManagerFactory configuration.
	 * <p>Default is none, indicating the default EntityManagerFactory
	 * configuration. The persistence provider will throw an exception if
	 * ambiguous EntityManager configurations are found.
	 * @see javax.persistence.Persistence#createEntityManagerFactory(String)
	 */
	public void setPersistenceUnitName(@Nullable String persistenceUnitName) {
		this.persistenceUnitName = persistenceUnitName;
	}

	@Override
	@Nullable
	public String getPersistenceUnitName() {
		return this.persistenceUnitName;
	}

	
Specify JPA properties, to be passed into Persistence.createEntityManagerFactory (if any). 
Can be populated with a String "value" (parsed via PropertiesEditor) or a
"props" element in XML bean definitions.
See Also:
Persistence.createEntityManagerFactory(String, Map)
PersistenceProvider.createContainerEntityManagerFactory(PersistenceUnitInfo, Map)/**
	 * Specify JPA properties, to be passed into
	 * {@code Persistence.createEntityManagerFactory} (if any).
	 * <p>Can be populated with a String "value" (parsed via PropertiesEditor) or a
	 * "props" element in XML bean definitions.
	 * @see javax.persistence.Persistence#createEntityManagerFactory(String, java.util.Map)
	 * @see javax.persistence.spi.PersistenceProvider#createContainerEntityManagerFactory(javax.persistence.spi.PersistenceUnitInfo, java.util.Map)
	 */
	public void setJpaProperties(Properties jpaProperties) {
		CollectionUtils.mergePropertiesIntoMap(jpaProperties, this.jpaPropertyMap);
	}

	
Specify JPA properties as a Map, to be passed into Persistence.createEntityManagerFactory (if any). 
Can be populated with a "map" or "props" element in XML bean definitions.
See Also:
Persistence.createEntityManagerFactory(String, Map)
PersistenceProvider.createContainerEntityManagerFactory(PersistenceUnitInfo, Map)/**
	 * Specify JPA properties as a Map, to be passed into
	 * {@code Persistence.createEntityManagerFactory} (if any).
	 * <p>Can be populated with a "map" or "props" element in XML bean definitions.
	 * @see javax.persistence.Persistence#createEntityManagerFactory(String, java.util.Map)
	 * @see javax.persistence.spi.PersistenceProvider#createContainerEntityManagerFactory(javax.persistence.spi.PersistenceUnitInfo, java.util.Map)
	 */
	public void setJpaPropertyMap(@Nullable Map<String, ?> jpaProperties) {
		if (jpaProperties != null) {
			this.jpaPropertyMap.putAll(jpaProperties);
		}
	}

	
Allow Map access to the JPA properties to be passed to the persistence
provider, with the option to add or override specific entries.
Useful for specifying entries directly, for example via
"jpaPropertyMap[myKey]".
/**
	 * Allow Map access to the JPA properties to be passed to the persistence
	 * provider, with the option to add or override specific entries.
	 * <p>Useful for specifying entries directly, for example via
	 * "jpaPropertyMap[myKey]".
	 */
	public Map<String, Object> getJpaPropertyMap() {
		return this.jpaPropertyMap;
	}

	
Specify the (potentially vendor-specific) EntityManagerFactory interface
that this EntityManagerFactory proxy is supposed to implement.
The default will be taken from the specific JpaVendorAdapter, if any, or set to the standard javax.persistence.EntityManagerFactory interface else. 
See Also:
JpaVendorAdapter.getEntityManagerFactoryInterface()/**
	 * Specify the (potentially vendor-specific) EntityManagerFactory interface
	 * that this EntityManagerFactory proxy is supposed to implement.
	 * <p>The default will be taken from the specific JpaVendorAdapter, if any,
	 * or set to the standard {@code javax.persistence.EntityManagerFactory}
	 * interface else.
	 * @see JpaVendorAdapter#getEntityManagerFactoryInterface()
	 */
	public void setEntityManagerFactoryInterface(Class<? extends EntityManagerFactory> emfInterface) {
		this.entityManagerFactoryInterface = emfInterface;
	}

	
Specify the (potentially vendor-specific) EntityManager interface
that this factory's EntityManagers are supposed to implement.
The default will be taken from the specific JpaVendorAdapter, if any, or set to the standard javax.persistence.EntityManager interface else. 
See Also:
JpaVendorAdapter.getEntityManagerInterface()
EntityManagerFactoryInfo.getEntityManagerInterface()/**
	 * Specify the (potentially vendor-specific) EntityManager interface
	 * that this factory's EntityManagers are supposed to implement.
	 * <p>The default will be taken from the specific JpaVendorAdapter, if any,
	 * or set to the standard {@code javax.persistence.EntityManager}
	 * interface else.
	 * @see JpaVendorAdapter#getEntityManagerInterface()
	 * @see EntityManagerFactoryInfo#getEntityManagerInterface()
	 */
	public void setEntityManagerInterface(@Nullable Class<? extends EntityManager> emInterface) {
		this.entityManagerInterface = emInterface;
	}

	@Override
	@Nullable
	public Class<? extends EntityManager> getEntityManagerInterface() {
		return this.entityManagerInterface;
	}

	
Specify the vendor-specific JpaDialect implementation to associate with
this EntityManagerFactory. This will be exposed through the
EntityManagerFactoryInfo interface, to be picked up as default dialect by
accessors that intend to use JpaDialect functionality.
See Also:
getJpaDialect.getJpaDialect()/**
	 * Specify the vendor-specific JpaDialect implementation to associate with
	 * this EntityManagerFactory. This will be exposed through the
	 * EntityManagerFactoryInfo interface, to be picked up as default dialect by
	 * accessors that intend to use JpaDialect functionality.
	 * @see EntityManagerFactoryInfo#getJpaDialect()
	 */
	public void setJpaDialect(@Nullable JpaDialect jpaDialect) {
		this.jpaDialect = jpaDialect;
	}

	@Override
	@Nullable
	public JpaDialect getJpaDialect() {
		return this.jpaDialect;
	}

	
Specify the JpaVendorAdapter implementation for the desired JPA provider,
if any. This will initialize appropriate defaults for the given provider,
such as persistence provider class and JpaDialect, unless locally
overridden in this FactoryBean.
/**
	 * Specify the JpaVendorAdapter implementation for the desired JPA provider,
	 * if any. This will initialize appropriate defaults for the given provider,
	 * such as persistence provider class and JpaDialect, unless locally
	 * overridden in this FactoryBean.
	 */
	public void setJpaVendorAdapter(@Nullable JpaVendorAdapter jpaVendorAdapter) {
		this.jpaVendorAdapter = jpaVendorAdapter;
	}

	
Return the JpaVendorAdapter implementation for this EntityManagerFactory, or null if not known. /**
	 * Return the JpaVendorAdapter implementation for this EntityManagerFactory,
	 * or {@code null} if not known.
	 */
	@Nullable
	public JpaVendorAdapter getJpaVendorAdapter() {
		return this.jpaVendorAdapter;
	}

	
Specify an asynchronous executor for background bootstrapping, e.g. a SimpleAsyncTaskExecutor. 
EntityManagerFactory initialization will then switch into background bootstrap mode, with a EntityManagerFactory proxy immediately returned for injection purposes instead of waiting for the JPA provider's bootstrapping to complete. However, note that the first actual call to a EntityManagerFactory method will then block until the JPA provider's bootstrapping completed, if not ready by then. For maximum benefit, make sure to avoid early EntityManagerFactory calls in init methods of related beans, even for metadata introspection purposes. 
Since:
4.3/**
	 * Specify an asynchronous executor for background bootstrapping,
	 * e.g. a {@link org.springframework.core.task.SimpleAsyncTaskExecutor}.
	 * <p>{@code EntityManagerFactory} initialization will then switch into background
	 * bootstrap mode, with a {@code EntityManagerFactory} proxy immediately returned for
	 * injection purposes instead of waiting for the JPA provider's bootstrapping to complete.
	 * However, note that the first actual call to a {@code EntityManagerFactory} method will
	 * then block until the JPA provider's bootstrapping completed, if not ready by then.
	 * For maximum benefit, make sure to avoid early {@code EntityManagerFactory} calls
	 * in init methods of related beans, even for metadata introspection purposes.
	 * @since 4.3
	 */
	public void setBootstrapExecutor(@Nullable AsyncTaskExecutor bootstrapExecutor) {
		this.bootstrapExecutor = bootstrapExecutor;
	}

	
Return the asynchronous executor for background bootstrapping, if any.
Since:
4.3/**
	 * Return the asynchronous executor for background bootstrapping, if any.
	 * @since 4.3
	 */
	@Nullable
	public AsyncTaskExecutor getBootstrapExecutor() {
		return this.bootstrapExecutor;
	}

	@Override
	public void setBeanClassLoader(ClassLoader classLoader) {
		this.beanClassLoader = classLoader;
	}

	@Override
	public ClassLoader getBeanClassLoader() {
		return this.beanClassLoader;
	}

	@Override
	public void setBeanFactory(BeanFactory beanFactory) {
		this.beanFactory = beanFactory;
	}

	@Override
	public void setBeanName(String name) {
		this.beanName = name;
	}


	@Override
	public void afterPropertiesSet() throws PersistenceException {
		JpaVendorAdapter jpaVendorAdapter = getJpaVendorAdapter();
		if (jpaVendorAdapter != null) {
			if (this.persistenceProvider == null) {
				this.persistenceProvider = jpaVendorAdapter.getPersistenceProvider();
			}
			PersistenceUnitInfo pui = getPersistenceUnitInfo();
			Map<String, ?> vendorPropertyMap = (pui != null ? jpaVendorAdapter.getJpaPropertyMap(pui) :
					jpaVendorAdapter.getJpaPropertyMap());
			if (!CollectionUtils.isEmpty(vendorPropertyMap)) {
				vendorPropertyMap.forEach((key, value) -> {
					if (!this.jpaPropertyMap.containsKey(key)) {
						this.jpaPropertyMap.put(key, value);
					}
				});
			}
			if (this.entityManagerFactoryInterface == null) {
				this.entityManagerFactoryInterface = jpaVendorAdapter.getEntityManagerFactoryInterface();
				if (!ClassUtils.isVisible(this.entityManagerFactoryInterface, this.beanClassLoader)) {
					this.entityManagerFactoryInterface = EntityManagerFactory.class;
				}
			}
			if (this.entityManagerInterface == null) {
				this.entityManagerInterface = jpaVendorAdapter.getEntityManagerInterface();
				if (!ClassUtils.isVisible(this.entityManagerInterface, this.beanClassLoader)) {
					this.entityManagerInterface = EntityManager.class;
				}
			}
			if (this.jpaDialect == null) {
				this.jpaDialect = jpaVendorAdapter.getJpaDialect();
			}
		}

		AsyncTaskExecutor bootstrapExecutor = getBootstrapExecutor();
		if (bootstrapExecutor != null) {
			this.nativeEntityManagerFactoryFuture = bootstrapExecutor.submit(this::buildNativeEntityManagerFactory);
		}
		else {
			this.nativeEntityManagerFactory = buildNativeEntityManagerFactory();
		}

		// Wrap the EntityManagerFactory in a factory implementing all its interfaces.
		// This allows interception of createEntityManager methods to return an
		// application-managed EntityManager proxy that automatically joins
		// existing transactions.
		this.entityManagerFactory = createEntityManagerFactoryProxy(this.nativeEntityManagerFactory);
	}

	private EntityManagerFactory buildNativeEntityManagerFactory() {
		EntityManagerFactory emf;
		try {
			emf = createNativeEntityManagerFactory();
		}
		catch (PersistenceException ex) {
			if (ex.getClass() == PersistenceException.class) {
				// Plain PersistenceException wrapper for underlying exception?
				// Make sure the nested exception message is properly exposed,
				// along the lines of Spring's NestedRuntimeException.getMessage()
				Throwable cause = ex.getCause();
				if (cause != null) {
					String message = ex.getMessage();
					String causeString = cause.toString();
					if (!message.endsWith(causeString)) {
						throw new PersistenceException(message + "; nested exception is " + causeString, cause);
					}
				}
			}
			throw ex;
		}

		JpaVendorAdapter jpaVendorAdapter = getJpaVendorAdapter();
		if (jpaVendorAdapter != null) {
			jpaVendorAdapter.postProcessEntityManagerFactory(emf);
		}

		if (logger.isInfoEnabled()) {
			logger.info("Initialized JPA EntityManagerFactory for persistence unit '" + getPersistenceUnitName() + "'");
		}
		return emf;
	}

	
Create a proxy for the given EntityManagerFactory. We do this to be able to return a transaction-aware proxy for an application-managed EntityManager. 
Params:
emf – the EntityManagerFactory as returned by the persistence provider,
if initialized already
Returns:
the EntityManagerFactory proxy/**
	 * Create a proxy for the given {@link EntityManagerFactory}. We do this to be able to
	 * return a transaction-aware proxy for an application-managed {@link EntityManager}.
	 * @param emf the EntityManagerFactory as returned by the persistence provider,
	 * if initialized already
	 * @return the EntityManagerFactory proxy
	 */
	protected EntityManagerFactory createEntityManagerFactoryProxy(@Nullable EntityManagerFactory emf) {
		Set<Class<?>> ifcs = new LinkedHashSet<>();
		Class<?> entityManagerFactoryInterface = this.entityManagerFactoryInterface;
		if (entityManagerFactoryInterface != null) {
			ifcs.add(entityManagerFactoryInterface);
		}
		else if (emf != null) {
			ifcs.addAll(ClassUtils.getAllInterfacesForClassAsSet(emf.getClass(), this.beanClassLoader));
		}
		else {
			ifcs.add(EntityManagerFactory.class);
		}
		ifcs.add(EntityManagerFactoryInfo.class);

		try {
			return (EntityManagerFactory) Proxy.newProxyInstance(this.beanClassLoader,
					ClassUtils.toClassArray(ifcs), new ManagedEntityManagerFactoryInvocationHandler(this));
		}
		catch (IllegalArgumentException ex) {
			if (entityManagerFactoryInterface != null) {
				throw new IllegalStateException("EntityManagerFactory interface [" + entityManagerFactoryInterface +
						"] seems to conflict with Spring's EntityManagerFactoryInfo mixin - consider resetting the "+
						"'entityManagerFactoryInterface' property to plain [javax.persistence.EntityManagerFactory]", ex);
			}
			else {
				throw new IllegalStateException("Conflicting EntityManagerFactory interfaces - " +
						"consider specifying the 'jpaVendorAdapter' or 'entityManagerFactoryInterface' property " +
						"to select a specific EntityManagerFactory interface to proceed with", ex);
			}
		}
	}

	
Delegate an incoming invocation from the proxy, dispatching to EntityManagerFactoryInfo
or the native EntityManagerFactory accordingly.
/**
	 * Delegate an incoming invocation from the proxy, dispatching to EntityManagerFactoryInfo
	 * or the native EntityManagerFactory accordingly.
	 */
	Object invokeProxyMethod(Method method, @Nullable Object[] args) throws Throwable {
		if (method.getDeclaringClass().isAssignableFrom(EntityManagerFactoryInfo.class)) {
			return method.invoke(this, args);
		}
		else if (method.getName().equals("createEntityManager") && args != null && args.length > 0 &&
				args[0] == SynchronizationType.SYNCHRONIZED) {
			// JPA 2.1's createEntityManager(SynchronizationType, Map)
			// Redirect to plain createEntityManager and add synchronization semantics through Spring proxy
			EntityManager rawEntityManager = (args.length > 1 ?
					getNativeEntityManagerFactory().createEntityManager((Map<?, ?>) args[1]) :
					getNativeEntityManagerFactory().createEntityManager());
			return ExtendedEntityManagerCreator.createApplicationManagedEntityManager(rawEntityManager, this, true);
		}

		// Look for Query arguments, primarily JPA 2.1's addNamedQuery(String, Query)
		if (args != null) {
			for (int i = 0; i < args.length; i++) {
				Object arg = args[i];
				if (arg instanceof Query && Proxy.isProxyClass(arg.getClass())) {
					// Assumably a Spring-generated proxy from SharedEntityManagerCreator:
					// since we're passing it back to the native EntityManagerFactory,
					// let's unwrap it to the original Query object from the provider.
					try {
						args[i] = ((Query) arg).unwrap(null);
					}
					catch (RuntimeException ex) {
						// Ignore - simply proceed with given Query object then
					}
				}
			}
		}

		// Standard delegation to the native factory, just post-processing EntityManager return values
		Object retVal = method.invoke(getNativeEntityManagerFactory(), args);
		if (retVal instanceof EntityManager) {
			// Any other createEntityManager variant - expecting non-synchronized semantics
			EntityManager rawEntityManager = (EntityManager) retVal;
			retVal = ExtendedEntityManagerCreator.createApplicationManagedEntityManager(rawEntityManager, this, false);
		}
		return retVal;
	}

	
Subclasses must implement this method to create the EntityManagerFactory that will be returned by the getObject() method. 
Throws:
PersistenceException – if the EntityManager cannot be created
Returns:
the EntityManagerFactory instance returned by this FactoryBean/**
	 * Subclasses must implement this method to create the EntityManagerFactory
	 * that will be returned by the {@code getObject()} method.
	 * @return the EntityManagerFactory instance returned by this FactoryBean
	 * @throws PersistenceException if the EntityManager cannot be created
	 */
	protected abstract EntityManagerFactory createNativeEntityManagerFactory() throws PersistenceException;


	
Implementation of the PersistenceExceptionTranslator interface, as
autodetected by Spring's PersistenceExceptionTranslationPostProcessor.
Uses the dialect's conversion if possible; otherwise falls back to
standard JPA exception conversion.
See Also:
PersistenceExceptionTranslationPostProcessor
PersistenceExceptionTranslator.translateExceptionIfPossible
EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible/**
	 * Implementation of the PersistenceExceptionTranslator interface, as
	 * autodetected by Spring's PersistenceExceptionTranslationPostProcessor.
	 * <p>Uses the dialect's conversion if possible; otherwise falls back to
	 * standard JPA exception conversion.
	 * @see org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor
	 * @see JpaDialect#translateExceptionIfPossible
	 * @see EntityManagerFactoryUtils#convertJpaAccessExceptionIfPossible
	 */
	@Override
	@Nullable
	public DataAccessException translateExceptionIfPossible(RuntimeException ex) {
		JpaDialect jpaDialect = getJpaDialect();
		return (jpaDialect != null ? jpaDialect.translateExceptionIfPossible(ex) :
				EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(ex));
	}

	@Override
	public EntityManagerFactory getNativeEntityManagerFactory() {
		if (this.nativeEntityManagerFactory != null) {
			return this.nativeEntityManagerFactory;
		}
		else {
			Assert.state(this.nativeEntityManagerFactoryFuture != null, "No native EntityManagerFactory available");
			try {
				return this.nativeEntityManagerFactoryFuture.get();
			}
			catch (InterruptedException ex) {
				Thread.currentThread().interrupt();
				throw new IllegalStateException("Interrupted during initialization of native EntityManagerFactory", ex);
			}
			catch (ExecutionException ex) {
				Throwable cause = ex.getCause();
				if (cause instanceof PersistenceException) {
					// Rethrow a provider configuration exception (possibly with a nested cause) directly
					throw (PersistenceException) cause;
				}
				throw new IllegalStateException("Failed to asynchronously initialize native EntityManagerFactory: " +
						ex.getMessage(), cause);
			}
		}
	}

	@Override
	@Nullable
	public PersistenceUnitInfo getPersistenceUnitInfo() {
		return null;
	}

	@Override
	@Nullable
	public DataSource getDataSource() {
		return null;
	}


	
Return the singleton EntityManagerFactory.
/**
	 * Return the singleton EntityManagerFactory.
	 */
	@Override
	@Nullable
	public EntityManagerFactory getObject() {
		return this.entityManagerFactory;
	}

	@Override
	public Class<? extends EntityManagerFactory> getObjectType() {
		return (this.entityManagerFactory != null ? this.entityManagerFactory.getClass() : EntityManagerFactory.class);
	}

	@Override
	public boolean isSingleton() {
		return true;
	}


	
Close the EntityManagerFactory on bean factory shutdown.
/**
	 * Close the EntityManagerFactory on bean factory shutdown.
	 */
	@Override
	public void destroy() {
		if (this.entityManagerFactory != null) {
			if (logger.isInfoEnabled()) {
				logger.info("Closing JPA EntityManagerFactory for persistence unit '" + getPersistenceUnitName() + "'");
			}
			this.entityManagerFactory.close();
		}
	}


	//---------------------------------------------------------------------
	// Serialization support
	//---------------------------------------------------------------------

	private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
		throw new NotSerializableException("An EntityManagerFactoryBean itself is not deserializable - " +
				"just a SerializedEntityManagerFactoryBeanReference is");
	}

	protected Object writeReplace() throws ObjectStreamException {
		if (this.beanFactory != null && this.beanName != null) {
			return new SerializedEntityManagerFactoryBeanReference(this.beanFactory, this.beanName);
		}
		else {
			throw new NotSerializableException("EntityManagerFactoryBean does not run within a BeanFactory");
		}
	}


	
Minimal bean reference to the surrounding AbstractEntityManagerFactoryBean.
Resolved to the actual AbstractEntityManagerFactoryBean instance on deserialization.
/**
	 * Minimal bean reference to the surrounding AbstractEntityManagerFactoryBean.
	 * Resolved to the actual AbstractEntityManagerFactoryBean instance on deserialization.
	 */
	@SuppressWarnings("serial")
	private static class SerializedEntityManagerFactoryBeanReference implements Serializable {

		private final BeanFactory beanFactory;

		private final String lookupName;

		public SerializedEntityManagerFactoryBeanReference(BeanFactory beanFactory, String beanName) {
			this.beanFactory = beanFactory;
			this.lookupName = BeanFactory.FACTORY_BEAN_PREFIX + beanName;
		}

		private Object readResolve() {
			return this.beanFactory.getBean(this.lookupName, AbstractEntityManagerFactoryBean.class);
		}
	}


	
Dynamic proxy invocation handler for an EntityManagerFactory, returning a proxy EntityManager (if necessary) from createEntityManager methods. /**
	 * Dynamic proxy invocation handler for an {@link EntityManagerFactory}, returning a
	 * proxy {@link EntityManager} (if necessary) from {@code createEntityManager} methods.
	 */
	@SuppressWarnings("serial")
	private static class ManagedEntityManagerFactoryInvocationHandler implements InvocationHandler, Serializable {

		private final AbstractEntityManagerFactoryBean entityManagerFactoryBean;

		public ManagedEntityManagerFactoryInvocationHandler(AbstractEntityManagerFactoryBean emfb) {
			this.entityManagerFactoryBean = emfb;
		}

		@Override
		public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
			try {
				if (method.getName().equals("equals")) {
					// Only consider equal when proxies are identical.
					return (proxy == args[0]);
				}
				else if (method.getName().equals("hashCode")) {
					// Use hashCode of EntityManagerFactory proxy.
					return System.identityHashCode(proxy);
				}
				else if (method.getName().equals("unwrap")) {
					// Handle JPA 2.1 unwrap method - could be a proxy match.
					Class<?> targetClass = (Class<?>) args[0];
					if (targetClass == null) {
						return this.entityManagerFactoryBean.getNativeEntityManagerFactory();
					}
					else if (targetClass.isInstance(proxy)) {
						return proxy;
					}
				}
				return this.entityManagerFactoryBean.invokeProxyMethod(method, args);
			}
			catch (InvocationTargetException ex) {
				throw ex.getTargetException();
			}
		}
	}

}