/*
 * 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 javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceException;
import javax.persistence.SharedCacheMode;
import javax.persistence.ValidationMode;
import javax.persistence.spi.PersistenceProvider;
import javax.persistence.spi.PersistenceUnitInfo;
import javax.sql.DataSource;

import org.springframework.beans.BeanUtils;
import org.springframework.context.ResourceLoaderAware;
import org.springframework.context.weaving.LoadTimeWeaverAware;
import org.springframework.core.io.ResourceLoader;
import org.springframework.instrument.classloading.LoadTimeWeaver;
import org.springframework.jdbc.datasource.lookup.SingleDataSourceLookup;
import org.springframework.lang.Nullable;
import org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager;
import org.springframework.orm.jpa.persistenceunit.PersistenceUnitManager;
import org.springframework.orm.jpa.persistenceunit.PersistenceUnitPostProcessor;
import org.springframework.orm.jpa.persistenceunit.SmartPersistenceUnitInfo;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;

FactoryBean that creates a JPA EntityManagerFactory according to JPA's standard container bootstrap contract. This is the most powerful way to set up a shared JPA EntityManagerFactory in a Spring application context; the EntityManagerFactory can then be passed to JPA-based DAOs via dependency injection. Note that switching to a JNDI lookup or to a LocalEntityManagerFactoryBean definition is just a matter of configuration! 
As with LocalEntityManagerFactoryBean, configuration settings are usually read in from a META-INF/persistence.xml config file, residing in the class path, according to the general JPA configuration contract. However, this FactoryBean is more flexible in that you can override the location of the persistence.xml file, specify the JDBC DataSources to link to, etc. Furthermore, it allows for pluggable class instrumentation through Spring's LoadTimeWeaver abstraction, instead of being tied to a special VM agent specified on JVM startup. 
Internally, this FactoryBean parses the persistence.xml file itself and creates a corresponding PersistenceUnitInfo object (with further configuration merged in, such as JDBC DataSources and the Spring LoadTimeWeaver), to be passed to the chosen JPA PersistenceProvider. This corresponds to a local JPA container with full support for the standard JPA container contract. 
The exposed EntityManagerFactory object will implement all the interfaces of the underlying native EntityManagerFactory returned by the PersistenceProvider, plus the EntityManagerFactoryInfo interface which exposes additional metadata as assembled by this FactoryBean. 
NOTE: Spring's JPA support requires JPA 2.1 or higher, as of Spring 5.0.
JPA 1.0/2.0 based applications are still supported; however, a JPA 2.1 compliant
persistence provider is needed at runtime.
Author:
Juergen Hoeller, Rod Johnson
See Also:
setPersistenceXmlLocation
AbstractEntityManagerFactoryBean.setJpaProperties
AbstractEntityManagerFactoryBean.setJpaVendorAdapter
setLoadTimeWeaver
setDataSource
EntityManagerFactoryInfo
LocalEntityManagerFactoryBean
SharedEntityManagerBean
PersistenceProvider.createContainerEntityManagerFactory
Since:
2.0/**
 * {@link org.springframework.beans.factory.FactoryBean} that creates a JPA
 * {@link javax.persistence.EntityManagerFactory} according to JPA's standard
 * <i>container</i> bootstrap contract. This is the most powerful way to set
 * up a shared JPA EntityManagerFactory in a Spring application context;
 * the EntityManagerFactory can then be passed to JPA-based DAOs via
 * dependency injection. Note that switching to a JNDI lookup or to a
 * {@link LocalEntityManagerFactoryBean} definition is just a matter of
 * configuration!
 *
 * <p>As with {@link LocalEntityManagerFactoryBean}, configuration settings
 * are usually read in from a {@code META-INF/persistence.xml} config file,
 * residing in the class path, according to the general JPA configuration contract.
 * However, this FactoryBean is more flexible in that you can override the location
 * of the {@code persistence.xml} file, specify the JDBC DataSources to link to,
 * etc. Furthermore, it allows for pluggable class instrumentation through Spring's
 * {@link org.springframework.instrument.classloading.LoadTimeWeaver} abstraction,
 * instead of being tied to a special VM agent specified on JVM startup.
 *
 * <p>Internally, this FactoryBean parses the {@code persistence.xml} file
 * itself and creates a corresponding {@link javax.persistence.spi.PersistenceUnitInfo}
 * object (with further configuration merged in, such as JDBC DataSources and the
 * Spring LoadTimeWeaver), to be passed to the chosen JPA
 * {@link javax.persistence.spi.PersistenceProvider}. This corresponds to a
 * local JPA container with full support for the standard JPA container contract.
 *
 * <p>The exposed EntityManagerFactory object will implement all the interfaces of
 * the underlying native EntityManagerFactory returned by the PersistenceProvider,
 * plus the {@link EntityManagerFactoryInfo} interface which exposes additional
 * metadata as assembled by this FactoryBean.
 *
 * <p><b>NOTE: Spring's JPA support requires JPA 2.1 or higher, as of Spring 5.0.</b>
 * JPA 1.0/2.0 based applications are still supported; however, a JPA 2.1 compliant
 * persistence provider is needed at runtime.
 *
 * @author Juergen Hoeller
 * @author Rod Johnson
 * @since 2.0
 * @see #setPersistenceXmlLocation
 * @see #setJpaProperties
 * @see #setJpaVendorAdapter
 * @see #setLoadTimeWeaver
 * @see #setDataSource
 * @see EntityManagerFactoryInfo
 * @see LocalEntityManagerFactoryBean
 * @see org.springframework.orm.jpa.support.SharedEntityManagerBean
 * @see javax.persistence.spi.PersistenceProvider#createContainerEntityManagerFactory
 */
@SuppressWarnings("serial")
public class LocalContainerEntityManagerFactoryBean extends AbstractEntityManagerFactoryBean
		implements ResourceLoaderAware, LoadTimeWeaverAware {

	@Nullable
	private PersistenceUnitManager persistenceUnitManager;

	private final DefaultPersistenceUnitManager internalPersistenceUnitManager = new DefaultPersistenceUnitManager();

	@Nullable
	private PersistenceUnitInfo persistenceUnitInfo;


	
Set the PersistenceUnitManager to use for obtaining the JPA persistence unit
that this FactoryBean is supposed to build an EntityManagerFactory for.
The default is to rely on the local settings specified on this FactoryBean,
such as "persistenceXmlLocation", "dataSource" and "loadTimeWeaver".
For reuse of existing persistence unit configuration or more advanced forms of custom persistence unit handling, consider defining a separate PersistenceUnitManager bean (typically a DefaultPersistenceUnitManager instance) and linking it in here. persistence.xml location, DataSource configuration and LoadTimeWeaver will be defined on that separate DefaultPersistenceUnitManager bean in such a scenario. 
See Also:
setPersistenceXmlLocation
setDataSource
setLoadTimeWeaver
DefaultPersistenceUnitManager/**
	 * Set the PersistenceUnitManager to use for obtaining the JPA persistence unit
	 * that this FactoryBean is supposed to build an EntityManagerFactory for.
	 * <p>The default is to rely on the local settings specified on this FactoryBean,
	 * such as "persistenceXmlLocation", "dataSource" and "loadTimeWeaver".
	 * <p>For reuse of existing persistence unit configuration or more advanced forms
	 * of custom persistence unit handling, consider defining a separate
	 * PersistenceUnitManager bean (typically a DefaultPersistenceUnitManager instance)
	 * and linking it in here. {@code persistence.xml} location, DataSource
	 * configuration and LoadTimeWeaver will be defined on that separate
	 * DefaultPersistenceUnitManager bean in such a scenario.
	 * @see #setPersistenceXmlLocation
	 * @see #setDataSource
	 * @see #setLoadTimeWeaver
	 * @see org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager
	 */
	public void setPersistenceUnitManager(PersistenceUnitManager persistenceUnitManager) {
		this.persistenceUnitManager = persistenceUnitManager;
	}

	
Set the location of the persistence.xml file we want to use. This is a Spring resource location. 
Default is "classpath:META-INF/persistence.xml".
NOTE: Only applied if no external PersistenceUnitManager specified.
Params:
persistenceXmlLocation – a Spring resource String identifying the location of the persistence.xml file that this LocalContainerEntityManagerFactoryBean should parse
See Also:
setPersistenceUnitManager/**
	 * Set the location of the {@code persistence.xml} file
	 * we want to use. This is a Spring resource location.
	 * <p>Default is "classpath:META-INF/persistence.xml".
	 * <p><b>NOTE: Only applied if no external PersistenceUnitManager specified.</b>
	 * @param persistenceXmlLocation a Spring resource String
	 * identifying the location of the {@code persistence.xml} file
	 * that this LocalContainerEntityManagerFactoryBean should parse
	 * @see #setPersistenceUnitManager
	 */
	public void setPersistenceXmlLocation(String persistenceXmlLocation) {
		this.internalPersistenceUnitManager.setPersistenceXmlLocation(persistenceXmlLocation);
	}

	
Uses the specified persistence unit name as the name of the default
persistence unit, if applicable.
NOTE: Only applied if no external PersistenceUnitManager specified.
See Also:
setDefaultPersistenceUnitName.setDefaultPersistenceUnitName/**
	 * Uses the specified persistence unit name as the name of the default
	 * persistence unit, if applicable.
	 * <p><b>NOTE: Only applied if no external PersistenceUnitManager specified.</b>
	 * @see DefaultPersistenceUnitManager#setDefaultPersistenceUnitName
	 */
	@Override
	public void setPersistenceUnitName(@Nullable String persistenceUnitName) {
		super.setPersistenceUnitName(persistenceUnitName);
		if (persistenceUnitName != null) {
			this.internalPersistenceUnitManager.setDefaultPersistenceUnitName(persistenceUnitName);
		}
	}

	
Set a persistence unit root location for the default persistence unit.
Default is "classpath:", that is, the root of the current classpath
(nearest root directory). To be overridden if unit-specific resolution
does not work and the classpath root is not appropriate either.
NOTE: Only applied if no external PersistenceUnitManager specified.
See Also:
DefaultPersistenceUnitManager.setDefaultPersistenceUnitRootLocation
Since:
4.3.3/**
	 * Set a persistence unit root location for the default persistence unit.
	 * <p>Default is "classpath:", that is, the root of the current classpath
	 * (nearest root directory). To be overridden if unit-specific resolution
	 * does not work and the classpath root is not appropriate either.
	 * <p><b>NOTE: Only applied if no external PersistenceUnitManager specified.</b>
	 * @since 4.3.3
	 * @see DefaultPersistenceUnitManager#setDefaultPersistenceUnitRootLocation
	 */
	public void setPersistenceUnitRootLocation(String defaultPersistenceUnitRootLocation) {
		this.internalPersistenceUnitManager.setDefaultPersistenceUnitRootLocation(defaultPersistenceUnitRootLocation);
	}

	
Set whether to use Spring-based scanning for entity classes in the classpath instead of using JPA's standard scanning of jar files with persistence.xml markers in them. In case of Spring-based scanning, no persistence.xml is necessary; all you need to do is to specify base packages to search here. 
Default is none. Specify packages to search for autodetection of your entity classes in the classpath. This is analogous to Spring's component-scan feature (ClassPathBeanDefinitionScanner). 
Note: There may be limitations in comparison to regular JPA scanning. In particular, JPA providers may pick up annotated packages for provider-specific annotations only when driven by persistence.xml. As of 4.1, Spring's scan can detect annotated packages as well if supported by the given JpaVendorAdapter (e.g. for Hibernate). 
If no explicit mapping resources have been specified in addition to these packages, Spring's setup looks for a default META-INF/orm.xml file in the classpath, registering it as a mapping resource for the default unit if the mapping file is not co-located with a persistence.xml file (in which case we assume it is only meant to be used with the persistence units defined there, like in standard JPA). 
NOTE: Only applied if no external PersistenceUnitManager specified.
Params:
packagesToScan – one or more base packages to search, analogous to
Spring's component-scan configuration for regular Spring components
See Also:
setPersistenceUnitManager
DefaultPersistenceUnitManager.setPackagesToScan/**
	 * Set whether to use Spring-based scanning for entity classes in the classpath
	 * instead of using JPA's standard scanning of jar files with {@code persistence.xml}
	 * markers in them. In case of Spring-based scanning, no {@code persistence.xml}
	 * is necessary; all you need to do is to specify base packages to search here.
	 * <p>Default is none. Specify packages to search for autodetection of your entity
	 * classes in the classpath. This is analogous to Spring's component-scan feature
	 * ({@link org.springframework.context.annotation.ClassPathBeanDefinitionScanner}).
	 * <p><b>Note: There may be limitations in comparison to regular JPA scanning.</b>
	 * In particular, JPA providers may pick up annotated packages for provider-specific
	 * annotations only when driven by {@code persistence.xml}. As of 4.1, Spring's
	 * scan can detect annotated packages as well if supported by the given
	 * {@link JpaVendorAdapter} (e.g. for Hibernate).
	 * <p>If no explicit {@link #setMappingResources mapping resources} have been
	 * specified in addition to these packages, Spring's setup looks for a default
	 * {@code META-INF/orm.xml} file in the classpath, registering it as a mapping
	 * resource for the default unit if the mapping file is not co-located with a
	 * {@code persistence.xml} file (in which case we assume it is only meant to be
	 * used with the persistence units defined there, like in standard JPA).
	 * <p><b>NOTE: Only applied if no external PersistenceUnitManager specified.</b>
	 * @param packagesToScan one or more base packages to search, analogous to
	 * Spring's component-scan configuration for regular Spring components
	 * @see #setPersistenceUnitManager
	 * @see DefaultPersistenceUnitManager#setPackagesToScan
	 */
	public void setPackagesToScan(String... packagesToScan) {
		this.internalPersistenceUnitManager.setPackagesToScan(packagesToScan);
	}

	
Specify one or more mapping resources (equivalent to <mapping-file> entries in persistence.xml) for the default persistence unit. Can be used on its own or in combination with entity scanning in the classpath, in both cases avoiding persistence.xml. 
Note that mapping resources must be relative to the classpath root, e.g. "META-INF/mappings.xml" or "com/mycompany/repository/mappings.xml", so that they can be loaded through ClassLoader.getResource. 
If no explicit mapping resources have been specified next to packages to scan, Spring's setup looks for a default META-INF/orm.xml file in the classpath, registering it as a mapping resource for the default unit if the mapping file is not co-located with a persistence.xml file (in which case we assume it is only meant to be used with the persistence units defined there, like in standard JPA). 
Note that specifying an empty array/list here suppresses the default META-INF/orm.xml check. On the other hand, explicitly specifying META-INF/orm.xml here will register that file even if it happens to be co-located with a persistence.xml file. 
NOTE: Only applied if no external PersistenceUnitManager specified.
See Also:
setPersistenceUnitManager
DefaultPersistenceUnitManager.setMappingResources/**
	 * Specify one or more mapping resources (equivalent to {@code <mapping-file>}
	 * entries in {@code persistence.xml}) for the default persistence unit.
	 * Can be used on its own or in combination with entity scanning in the classpath,
	 * in both cases avoiding {@code persistence.xml}.
	 * <p>Note that mapping resources must be relative to the classpath root,
	 * e.g. "META-INF/mappings.xml" or "com/mycompany/repository/mappings.xml",
	 * so that they can be loaded through {@code ClassLoader.getResource}.
	 * <p>If no explicit mapping resources have been specified next to
	 * {@link #setPackagesToScan packages to scan}, Spring's setup looks for a default
	 * {@code META-INF/orm.xml} file in the classpath, registering it as a mapping
	 * resource for the default unit if the mapping file is not co-located with a
	 * {@code persistence.xml} file (in which case we assume it is only meant to be
	 * used with the persistence units defined there, like in standard JPA).
	 * <p>Note that specifying an empty array/list here suppresses the default
	 * {@code META-INF/orm.xml} check. On the other hand, explicitly specifying
	 * {@code META-INF/orm.xml} here will register that file even if it happens
	 * to be co-located with a {@code persistence.xml} file.
	 * <p><b>NOTE: Only applied if no external PersistenceUnitManager specified.</b>
	 * @see #setPersistenceUnitManager
	 * @see DefaultPersistenceUnitManager#setMappingResources
	 */
	public void setMappingResources(String... mappingResources) {
		this.internalPersistenceUnitManager.setMappingResources(mappingResources);
	}

	
Specify the JPA 2.0 shared cache mode for this persistence unit, overriding a value in persistence.xml if set. 
NOTE: Only applied if no external PersistenceUnitManager specified.
See Also:
PersistenceUnitInfo.getSharedCacheMode()
setPersistenceUnitManager
Since:
4.0/**
	 * Specify the JPA 2.0 shared cache mode for this persistence unit,
	 * overriding a value in {@code persistence.xml} if set.
	 * <p><b>NOTE: Only applied if no external PersistenceUnitManager specified.</b>
	 * @since 4.0
	 * @see javax.persistence.spi.PersistenceUnitInfo#getSharedCacheMode()
	 * @see #setPersistenceUnitManager
	 */
	public void setSharedCacheMode(SharedCacheMode sharedCacheMode) {
		this.internalPersistenceUnitManager.setSharedCacheMode(sharedCacheMode);
	}

	
Specify the JPA 2.0 validation mode for this persistence unit, overriding a value in persistence.xml if set. 
NOTE: Only applied if no external PersistenceUnitManager specified.
See Also:
PersistenceUnitInfo.getValidationMode()
setPersistenceUnitManager
Since:
4.0/**
	 * Specify the JPA 2.0 validation mode for this persistence unit,
	 * overriding a value in {@code persistence.xml} if set.
	 * <p><b>NOTE: Only applied if no external PersistenceUnitManager specified.</b>
	 * @since 4.0
	 * @see javax.persistence.spi.PersistenceUnitInfo#getValidationMode()
	 * @see #setPersistenceUnitManager
	 */
	public void setValidationMode(ValidationMode validationMode) {
		this.internalPersistenceUnitManager.setValidationMode(validationMode);
	}

	
Specify the JDBC DataSource that the JPA persistence provider is supposed to use for accessing the database. This is an alternative to keeping the JDBC configuration in persistence.xml, passing in a Spring-managed DataSource instead. 
In JPA speak, a DataSource passed in here will be used as "nonJtaDataSource" on the PersistenceUnitInfo passed to the PersistenceProvider, as well as overriding data source configuration in persistence.xml (if any). Note that this variant typically works for JTA transaction management as well; if it does not, consider using the explicit setJtaDataSource instead. 
NOTE: Only applied if no external PersistenceUnitManager specified.
See Also:
PersistenceUnitInfo.getNonJtaDataSource()
setPersistenceUnitManager/**
	 * Specify the JDBC DataSource that the JPA persistence provider is supposed
	 * to use for accessing the database. This is an alternative to keeping the
	 * JDBC configuration in {@code persistence.xml}, passing in a Spring-managed
	 * DataSource instead.
	 * <p>In JPA speak, a DataSource passed in here will be used as "nonJtaDataSource"
	 * on the PersistenceUnitInfo passed to the PersistenceProvider, as well as
	 * overriding data source configuration in {@code persistence.xml} (if any).
	 * Note that this variant typically works for JTA transaction management as well;
	 * if it does not, consider using the explicit {@link #setJtaDataSource} instead.
	 * <p><b>NOTE: Only applied if no external PersistenceUnitManager specified.</b>
	 * @see javax.persistence.spi.PersistenceUnitInfo#getNonJtaDataSource()
	 * @see #setPersistenceUnitManager
	 */
	public void setDataSource(DataSource dataSource) {
		this.internalPersistenceUnitManager.setDataSourceLookup(new SingleDataSourceLookup(dataSource));
		this.internalPersistenceUnitManager.setDefaultDataSource(dataSource);
	}

	
Specify the JDBC DataSource that the JPA persistence provider is supposed to use for accessing the database. This is an alternative to keeping the JDBC configuration in persistence.xml, passing in a Spring-managed DataSource instead. 
In JPA speak, a DataSource passed in here will be used as "jtaDataSource" on the PersistenceUnitInfo passed to the PersistenceProvider, as well as overriding data source configuration in persistence.xml (if any). 
NOTE: Only applied if no external PersistenceUnitManager specified.
See Also:
PersistenceUnitInfo.getJtaDataSource()
setPersistenceUnitManager/**
	 * Specify the JDBC DataSource that the JPA persistence provider is supposed
	 * to use for accessing the database. This is an alternative to keeping the
	 * JDBC configuration in {@code persistence.xml}, passing in a Spring-managed
	 * DataSource instead.
	 * <p>In JPA speak, a DataSource passed in here will be used as "jtaDataSource"
	 * on the PersistenceUnitInfo passed to the PersistenceProvider, as well as
	 * overriding data source configuration in {@code persistence.xml} (if any).
	 * <p><b>NOTE: Only applied if no external PersistenceUnitManager specified.</b>
	 * @see javax.persistence.spi.PersistenceUnitInfo#getJtaDataSource()
	 * @see #setPersistenceUnitManager
	 */
	public void setJtaDataSource(DataSource jtaDataSource) {
		this.internalPersistenceUnitManager.setDataSourceLookup(new SingleDataSourceLookup(jtaDataSource));
		this.internalPersistenceUnitManager.setDefaultJtaDataSource(jtaDataSource);
	}

	
Set the PersistenceUnitPostProcessors to be applied to the
PersistenceUnitInfo used for creating this EntityManagerFactory.
Such post-processors can, for example, register further entity classes and jar files, in addition to the metadata read from persistence.xml. 
NOTE: Only applied if no external PersistenceUnitManager specified.
See Also:
setPersistenceUnitManager/**
	 * Set the PersistenceUnitPostProcessors to be applied to the
	 * PersistenceUnitInfo used for creating this EntityManagerFactory.
	 * <p>Such post-processors can, for example, register further entity
	 * classes and jar files, in addition to the metadata read from
	 * {@code persistence.xml}.
	 * <p><b>NOTE: Only applied if no external PersistenceUnitManager specified.</b>
	 * @see #setPersistenceUnitManager
	 */
	public void setPersistenceUnitPostProcessors(PersistenceUnitPostProcessor... postProcessors) {
		this.internalPersistenceUnitManager.setPersistenceUnitPostProcessors(postProcessors);
	}

	
Specify the Spring LoadTimeWeaver to use for class instrumentation according
to the JPA class transformer contract.
It is a not required to specify a LoadTimeWeaver: Most providers will be
able to provide a subset of their functionality without class instrumentation
as well, or operate with their VM agent specified on JVM startup.
In terms of Spring-provided weaving options, the most important ones are
InstrumentationLoadTimeWeaver, which requires a Spring-specific (but very general)
VM agent specified on JVM startup, and ReflectiveLoadTimeWeaver, which interacts
with an underlying ClassLoader based on specific extended methods being available
on it.
NOTE: As of Spring 2.5, the context's default LoadTimeWeaver (defined as bean with name "loadTimeWeaver") will be picked up automatically, if available, removing the need for LoadTimeWeaver configuration on each affected target bean. Consider using the context:load-time-weaver XML tag for creating such a shared LoadTimeWeaver (autodetecting the environment by default). 
NOTE: Only applied if no external PersistenceUnitManager specified. Otherwise, the external PersistenceUnitManager is responsible for the weaving configuration. 
See Also:
InstrumentationLoadTimeWeaver
ReflectiveLoadTimeWeaver/**
	 * Specify the Spring LoadTimeWeaver to use for class instrumentation according
	 * to the JPA class transformer contract.
	 * <p>It is a not required to specify a LoadTimeWeaver: Most providers will be
	 * able to provide a subset of their functionality without class instrumentation
	 * as well, or operate with their VM agent specified on JVM startup.
	 * <p>In terms of Spring-provided weaving options, the most important ones are
	 * InstrumentationLoadTimeWeaver, which requires a Spring-specific (but very general)
	 * VM agent specified on JVM startup, and ReflectiveLoadTimeWeaver, which interacts
	 * with an underlying ClassLoader based on specific extended methods being available
	 * on it.
	 * <p><b>NOTE:</b> As of Spring 2.5, the context's default LoadTimeWeaver (defined
	 * as bean with name "loadTimeWeaver") will be picked up automatically, if available,
	 * removing the need for LoadTimeWeaver configuration on each affected target bean.
	 * Consider using the {@code context:load-time-weaver} XML tag for creating
	 * such a shared LoadTimeWeaver (autodetecting the environment by default).
	 * <p><b>NOTE:</b> Only applied if no external PersistenceUnitManager specified.
	 * Otherwise, the external {@link #setPersistenceUnitManager PersistenceUnitManager}
	 * is responsible for the weaving configuration.
	 * @see org.springframework.instrument.classloading.InstrumentationLoadTimeWeaver
	 * @see org.springframework.instrument.classloading.ReflectiveLoadTimeWeaver
	 */
	@Override
	public void setLoadTimeWeaver(LoadTimeWeaver loadTimeWeaver) {
		this.internalPersistenceUnitManager.setLoadTimeWeaver(loadTimeWeaver);
	}

	@Override
	public void setResourceLoader(ResourceLoader resourceLoader) {
		this.internalPersistenceUnitManager.setResourceLoader(resourceLoader);
	}


	@Override
	public void afterPropertiesSet() throws PersistenceException {
		PersistenceUnitManager managerToUse = this.persistenceUnitManager;
		if (this.persistenceUnitManager == null) {
			this.internalPersistenceUnitManager.afterPropertiesSet();
			managerToUse = this.internalPersistenceUnitManager;
		}

		this.persistenceUnitInfo = determinePersistenceUnitInfo(managerToUse);
		JpaVendorAdapter jpaVendorAdapter = getJpaVendorAdapter();
		if (jpaVendorAdapter != null && this.persistenceUnitInfo instanceof SmartPersistenceUnitInfo) {
			String rootPackage = jpaVendorAdapter.getPersistenceProviderRootPackage();
			if (rootPackage != null) {
				((SmartPersistenceUnitInfo) this.persistenceUnitInfo).setPersistenceProviderPackageName(rootPackage);
			}
		}

		super.afterPropertiesSet();
	}

	@Override
	protected EntityManagerFactory createNativeEntityManagerFactory() throws PersistenceException {
		Assert.state(this.persistenceUnitInfo != null, "PersistenceUnitInfo not initialized");

		PersistenceProvider provider = getPersistenceProvider();
		if (provider == null) {
			String providerClassName = this.persistenceUnitInfo.getPersistenceProviderClassName();
			if (providerClassName == null) {
				throw new IllegalArgumentException(
						"No PersistenceProvider specified in EntityManagerFactory configuration, " +
						"and chosen PersistenceUnitInfo does not specify a provider class name either");
			}
			Class<?> providerClass = ClassUtils.resolveClassName(providerClassName, getBeanClassLoader());
			provider = (PersistenceProvider) BeanUtils.instantiateClass(providerClass);
		}

		if (logger.isDebugEnabled()) {
			logger.debug("Building JPA container EntityManagerFactory for persistence unit '" +
					this.persistenceUnitInfo.getPersistenceUnitName() + "'");
		}
		EntityManagerFactory emf =
				provider.createContainerEntityManagerFactory(this.persistenceUnitInfo, getJpaPropertyMap());
		postProcessEntityManagerFactory(emf, this.persistenceUnitInfo);

		return emf;
	}


	
Determine the PersistenceUnitInfo to use for the EntityManagerFactory
created by this bean.
The default implementation reads in all persistence unit infos from persistence.xml, as defined in the JPA specification. If no entity manager name was specified, it takes the first info in the array as returned by the reader. Otherwise, it checks for a matching name. 
Params:
persistenceUnitManager – the PersistenceUnitManager to obtain from
Returns:
the chosen PersistenceUnitInfo/**
	 * Determine the PersistenceUnitInfo to use for the EntityManagerFactory
	 * created by this bean.
	 * <p>The default implementation reads in all persistence unit infos from
	 * {@code persistence.xml}, as defined in the JPA specification.
	 * If no entity manager name was specified, it takes the first info in the
	 * array as returned by the reader. Otherwise, it checks for a matching name.
	 * @param persistenceUnitManager the PersistenceUnitManager to obtain from
	 * @return the chosen PersistenceUnitInfo
	 */
	protected PersistenceUnitInfo determinePersistenceUnitInfo(PersistenceUnitManager persistenceUnitManager) {
		if (getPersistenceUnitName() != null) {
			return persistenceUnitManager.obtainPersistenceUnitInfo(getPersistenceUnitName());
		}
		else {
			return persistenceUnitManager.obtainDefaultPersistenceUnitInfo();
		}
	}

	
Hook method allowing subclasses to customize the EntityManagerFactory
after its creation via the PersistenceProvider.
The default implementation is empty.
Params:
emf – the newly created EntityManagerFactory we are working with
pui – the PersistenceUnitInfo used to configure the EntityManagerFactory
See Also:
PersistenceProvider.createContainerEntityManagerFactory/**
	 * Hook method allowing subclasses to customize the EntityManagerFactory
	 * after its creation via the PersistenceProvider.
	 * <p>The default implementation is empty.
	 * @param emf the newly created EntityManagerFactory we are working with
	 * @param pui the PersistenceUnitInfo used to configure the EntityManagerFactory
	 * @see javax.persistence.spi.PersistenceProvider#createContainerEntityManagerFactory
	 */
	protected void postProcessEntityManagerFactory(EntityManagerFactory emf, PersistenceUnitInfo pui) {
	}


	@Override
	@Nullable
	public PersistenceUnitInfo getPersistenceUnitInfo() {
		return this.persistenceUnitInfo;
	}

	@Override
	@Nullable
	public String getPersistenceUnitName() {
		if (this.persistenceUnitInfo != null) {
			return this.persistenceUnitInfo.getPersistenceUnitName();
		}
		return super.getPersistenceUnitName();
	}

	@Override
	public DataSource getDataSource() {
		if (this.persistenceUnitInfo != null) {
			return (this.persistenceUnitInfo.getJtaDataSource() != null ?
					this.persistenceUnitInfo.getJtaDataSource() :
					this.persistenceUnitInfo.getNonJtaDataSource());
		}
		return (this.internalPersistenceUnitManager.getDefaultJtaDataSource() != null ?
				this.internalPersistenceUnitManager.getDefaultJtaDataSource() :
				this.internalPersistenceUnitManager.getDefaultDataSource());
	}

}