/**
    * Copyright 2005-2014 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.rice.krad.data.jpa;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  
  import javax.persistence.Converter;
  import javax.persistence.EntityManager;
  import javax.persistence.EntityManagerFactory;
  import javax.persistence.PersistenceException;
  import javax.persistence.spi.PersistenceProvider;
  import javax.persistence.spi.PersistenceUnitInfo;
  import javax.sql.DataSource;
  
  import org.kuali.rice.core.api.config.property.ConfigContext;
  import org.kuali.rice.krad.data.config.ConfigConstants;
  import org.kuali.rice.krad.data.jpa.converters.BooleanYNConverter;
  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.context.ResourceLoaderAware;
  import org.springframework.context.weaving.LoadTimeWeaverAware;
  import org.springframework.core.io.Resource;
  import org.springframework.core.io.ResourceLoader;
  import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
  import org.springframework.core.io.support.ResourcePatternResolver;
  import org.springframework.core.type.classreading.CachingMetadataReaderFactory;
  import org.springframework.core.type.classreading.MetadataReader;
  import org.springframework.core.type.classreading.MetadataReaderFactory;
  import org.springframework.core.type.filter.AnnotationTypeFilter;
  import org.springframework.core.type.filter.TypeFilter;
  import org.springframework.dao.DataAccessException;
  import org.springframework.dao.support.PersistenceExceptionTranslator;
  import org.springframework.instrument.classloading.LoadTimeWeaver;
  import org.springframework.orm.jpa.EntityManagerFactoryInfo;
  import org.springframework.orm.jpa.JpaDialect;
  import org.springframework.orm.jpa.JpaVendorAdapter;
  import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
  import org.springframework.orm.jpa.persistenceunit.DefaultPersistenceUnitManager;
  import org.springframework.orm.jpa.persistenceunit.MutablePersistenceUnitInfo;
  import org.springframework.orm.jpa.persistenceunit.PersistenceUnitManager;
  import org.springframework.orm.jpa.persistenceunit.PersistenceUnitPostProcessor;
  import org.springframework.util.ClassUtils;
  
  /**
   * A KRAD-managed {@link javax.persistence.EntityManagerFactory} factory bean which can be used to configure a JPA
   * persistence unit using the Spring Framework. This implementation does not support the use of a custom
   * PersistenceUnitManager, but rather stores and manages one internally. This is intended to be an alternative to direct
   * usage of Spring's {@link LocalContainerEntityManagerFactoryBean} in order to make JPA configuration with KRAD
   * simpler.
   *
   * <h1>Minimal Configuration</h1>
   *
   * <p>Minimal configuration of this factory bean will include the following:</p>
   *
   * <ul>
   *     <li>{@code persistenceUnitName}</li>
   *     <li>{@code dataSource} or {@code jtaDataSource}</li>
   *     <li>{@code persistenceProvider} or {@code jpaVendorAdapter}</li>
   * </ul>
   *
   * <p></p>Note that persistence unit names must be unique, so choose a name which is unlikely to clash
   * with any potential persistence units configured within the runtime environment.</p>
   *
   * <h1>Behavior</h1>
   *
   * <p>When leveraging this class, persistence.xml files are not used. Rather, persistence unit configuration is loaded
   * via the various settings provided on this factory bean which contain everything needed to create the desired
   * persistence unit configuration in the majority of cases. If a KRAD application needs more control over the
   * configuration of the persistence unit or wants to use persistence.xml and JPA's default bootstrapping and classpath
   * scanning behavior, an EntityManagerFactory can be configured using the other classes provided by the Spring
   * framework or by other means as needed. See {@link LocalContainerEntityManagerFactoryBean} for an alternative
   * approach.</p>
   *
   * <p>Only one of JTA or non-JTA datasource can be set. Depending on which one is set, the underlying persistence unit
   * will have it's {@link javax.persistence.spi.PersistenceUnitTransactionType} set to either RESOURCE_LOCAL or JTA. If
  * both of these are set, then this class will throw an {@code IllegalStateException} when the
  * {@link #afterPropertiesSet()} method is invoked by the Spring Framework.</p>
  *
  * <p>Elsewhere, this class delegates to implementations of {@link LocalContainerEntityManagerFactoryBean} and
  * {@link DefaultPersistenceUnitManager}, so information on the specific behavior of some of the settings and methods on
  * this class can be found on the javadoc for those classes as well.</p>
  *
  * <h1>JPA Property Defaults</h1>
  *
  * <p>When {@link #afterPropertiesSet()} is invoked, this class will scan the current {@link ConfigContext} for JPA
  * properties and make them available to the persistence unit. It will combine these with any properties that were set
  * directly on this factory bean via the {@link #setJpaProperties(java.util.Properties)} or
  * {@link #setJpaPropertyMap(java.util.Map)} methods.</p
  *
  * <p>This scanning occurs in the following order, items later in the list will override any properties from earlier if
  * they happen to set the same effective property value:</p>
  *
  * <ol>
  *   <li>Scan ConfigContext for properties that begin with "rice.krad.jpa.global." For any found, strip off this prefix
  *       prior to placing it into the JPA property map.</li>
  *   <li>Scan ConfigContext for properties that being with "rice.krad.jpa.&lt;persistence-unit-name&gt;" where
  *       "persistence-unit-name" is the configured name of this persistence unit. For any found, strip off this prefix
  *       prior to placing it into the JPA property map.</li>
  *   <li>Invoke {@link #loadCustomJpaDefaults(java.util.Map)} to allow for possible subclass customization of JPA
  *       property defaults</li>
  *   <li>Load the JPA properties configured via {@link #setJpaPropertyMap(java.util.Map)} and
  *   {@link #setJpaProperties(java.util.Properties)}. It is potentially non-deterministic which of these setters will
  *   take precedence over the other, so it is recommended to only invoke one of them on a given instance of this
  *   factory bean.</li>
  * </ol>
  *
  * <h1>Subclassing</h1>
  *
  * This class can be subclassed to provide additional specialized implementations of this factory bean. A potential use
  * for this might be to provide a factory bean that defaults certain values as part of it's default setup.
  *
  * @author Kuali Rice Team (rice.collab@kuali.org)
  */
 public class KradEntityManagerFactoryBean implements FactoryBean<EntityManagerFactory>, BeanClassLoaderAware,
         BeanFactoryAware, BeanNameAware, InitializingBean, DisposableBean, EntityManagerFactoryInfo,
         PersistenceExceptionTranslator, ResourceLoaderAware, LoadTimeWeaverAware {
 
 	private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger
 			.getLogger(KradEntityManagerFactoryBean.class);
 
     private static final boolean DEFAULT_EXCLUDE_UNLISTED_CLASSES = true;
     private static final String DEFAULT_CONVERTERS_PACKAGE = BooleanYNConverter.class.getPackage().getName();
 
     private final DefaultPersistenceUnitManager persistenceUnitManager;
     private final LocalContainerEntityManagerFactoryBean internalFactoryBean;
 
     private List<PersistenceUnitPostProcessor> persistenceUnitPostProcessors;
     private List<String> managedClassNames;
 	private List<String> converterPackageNames;
 
     public KradEntityManagerFactoryBean() {
         this.persistenceUnitPostProcessors = new ArrayList<PersistenceUnitPostProcessor>();
         this.managedClassNames = new ArrayList<String>();
 		this.converterPackageNames = new ArrayList<String>();
 		converterPackageNames.add(DEFAULT_CONVERTERS_PACKAGE); // set as default
         this.persistenceUnitManager = createPersistenceUnitManager();
         this.internalFactoryBean = createInternalFactoryBean(this.persistenceUnitManager);
         this.internalFactoryBean.setJpaPropertyMap(createDefaultJpaProperties());
     }
 
     /**
      * Retrieve a reference to the internal {@link LocalContainerEntityManagerFactoryBean} which is used by this factory
      * bean. Primarily intended to allow subclasses to access this internal factory bean when needed.
      *
      * @return the internal {@link LocalContainerEntityManagerFactoryBean} managed by this bean
      */
     protected LocalContainerEntityManagerFactoryBean getInternalFactoryBean() {
         return this.internalFactoryBean;
     }
 
     protected DefaultPersistenceUnitManager createPersistenceUnitManager() {
         DefaultPersistenceUnitManager pum = new DefaultPersistenceUnitManager();
         // IMPORTANT! - setting these to empty String arrays, this triggers the DefaultPersistenceUnitManager to
         // behave appropriately and ignore persistence.xml files from META-INF/persistence.xml as well as allowing for
         // an empty/minimal persistence unit to be created.
         //
         // Note that while Intellij complains about "Redundant array creation for calling varargs method", we really do
         // need to pass an empty array here in order for this code to work properly.
         pum.setPersistenceXmlLocations(new String[0]);
         pum.setMappingResources(new String[0]);
         pum.setPackagesToScan(new String[0]);
         return pum;
     }
 
     protected LocalContainerEntityManagerFactoryBean createInternalFactoryBean(PersistenceUnitManager manager) {
         LocalContainerEntityManagerFactoryBean delegate = new LocalContainerEntityManagerFactoryBean();
         delegate.setPersistenceUnitManager(manager);
         return delegate;
     }
 
     @Override
     public void afterPropertiesSet() throws PersistenceException {
         if (persistenceUnitManager.getDefaultJtaDataSource() != null &&
                 persistenceUnitManager.getDefaultDataSource() != null) {
 			throw new IllegalStateException(getPersistenceUnitName() + ": " + getClass().getSimpleName()
 					+ " was configured with both a JTA and Non-JTA "
                 + " datasource. Must configure one or the other, but not both.");
         }
 
         this.internalFactoryBean.setJpaPropertyMap(defaultAndMergeJpaProperties());
         persistenceUnitManager.setPersistenceUnitPostProcessors(assemblePersistenceUnitPostProcessors());
         persistenceUnitManager.afterPropertiesSet();
         internalFactoryBean.afterPropertiesSet();
     }
 
     private Map<String, ?> createDefaultJpaProperties() {
         Map<String, String> jpaProperties = new HashMap<String, String>();
         loadGlobalJpaDefaults(jpaProperties);
         loadPersistenceUnitJpaDefaults(jpaProperties);
         loadCustomJpaDefaults(jpaProperties);
 
         return jpaProperties;
     }
 
     private Map<String, ?> defaultAndMergeJpaProperties() {
         Map<String, Object> jpaProperties = new HashMap<String, Object>(createDefaultJpaProperties());
         Map<String, Object> configuredJpaPropertyMap = this.internalFactoryBean.getJpaPropertyMap();
         jpaProperties.putAll(configuredJpaPropertyMap);
 		if (LOG.isDebugEnabled()) {
 			LOG.debug(getPersistenceUnitName() + ": JPA Properties Set:\n" + jpaProperties);
 		}
 
         return jpaProperties;
     }
 
     /**
      * Allows for loading of custom JPA defaults by subclasses, default implementation does nothing so subclasses need
      * not call super.loadCustomJpaDefaults. Subclasses are free to override this method as they see fit. This method is
      * executed after other defaults are loaded. A reference to the current Map of JPA properties is passed. Subclasses
      * should take care if removing or overwriting any of the values which already exist in the given Map.
      *
      * @param jpaProperties the current Map of JPA property defaults
      */
     protected void loadCustomJpaDefaults(Map<String, String> jpaProperties) {
         // subclass can override
     }
 
     protected void loadGlobalJpaDefaults(Map<String, String> jpaProperties) {
         jpaProperties.putAll(ConfigContext.getCurrentContextConfig().getPropertiesWithPrefix(ConfigConstants.GLOBAL_JPA_PROPERTY_PREFIX,
                 true));
     }
 
     protected void loadPersistenceUnitJpaDefaults(Map<String, String> jpaProperties) {
         jpaProperties.putAll(ConfigContext.getCurrentContextConfig().getPropertiesWithPrefix(
                 constructPersistenceUnitJpaPropertyPrefix(), true));
     }
 
     protected String constructPersistenceUnitJpaPropertyPrefix() {
         return ConfigConstants.JPA_PROPERTY_PREFIX + getPersistenceUnitName() + ".";
     }
 
     protected PersistenceUnitPostProcessor[] assemblePersistenceUnitPostProcessors() {
         this.persistenceUnitPostProcessors = new ArrayList<PersistenceUnitPostProcessor>(this.persistenceUnitPostProcessors);
         this.persistenceUnitPostProcessors.add(new InternalPersistenceUnitPostProcessor());
         return this.persistenceUnitPostProcessors.toArray(new PersistenceUnitPostProcessor[this.persistenceUnitPostProcessors.size()]);
     }
 
     /**
      * Returns the list of all managed class names which have been configured on this factory bean. This list is
      * modifiable, so the returned list may be modified directly if desired.
      *
      * @return list of all managed class names, may be an empty list but will never return null
      */
     public List<String> getManagedClassNames() {
         return managedClassNames;
     }
 
     /**
      * Returns an array of the {@link PersistenceUnitPostProcessor} instances which have been configured on this
      * factory bean.
      *
      * @return array of post processors, may be empty but will never return null
      */
     public PersistenceUnitPostProcessor[] getPersistenceUnitPostProcessors() {
         return persistenceUnitPostProcessors.toArray(new PersistenceUnitPostProcessor[persistenceUnitPostProcessors.size()]);
     }
 
     /**
      * Returns a reference to the internal {@link DefaultPersistenceUnitManager} which is used by this factory bean.
      *
      * @return the internal persistence unit manager, will never return null
      */
     protected DefaultPersistenceUnitManager getPersistenceUnitManager() {
         return persistenceUnitManager;
     }
 
     @Override
     public void destroy() {
         internalFactoryBean.destroy();
     }
 
     @Override
     public Class<? extends EntityManagerFactory> getObjectType() {
         return internalFactoryBean.getObjectType();
     }
 
     @Override
     public boolean isSingleton() {
         return internalFactoryBean.isSingleton();
     }
 
     @Override
     public EntityManagerFactory getObject() {
         return internalFactoryBean.getObject();
     }
 
     @Override
     public EntityManagerFactory getNativeEntityManagerFactory() {
         return internalFactoryBean.getNativeEntityManagerFactory();
     }
 
     @Override
     public void setBeanName(String name) {
         internalFactoryBean.setBeanName(name);
     }
 
     @Override
     public void setBeanFactory(BeanFactory beanFactory) {
         internalFactoryBean.setBeanFactory(beanFactory);
     }
 
     @Override
     public ClassLoader getBeanClassLoader() {
         return internalFactoryBean.getBeanClassLoader();
     }
 
     @Override
     public void setBeanClassLoader(ClassLoader classLoader) {
         internalFactoryBean.setBeanClassLoader(classLoader);
     }
 
     @Override
     public Class<? extends EntityManager> getEntityManagerInterface() {
         return internalFactoryBean.getEntityManagerInterface();
     }
 
     @Override
     public void setLoadTimeWeaver(LoadTimeWeaver loadTimeWeaver) {
         persistenceUnitManager.setLoadTimeWeaver(loadTimeWeaver);
     }
 
     @Override
     public void setResourceLoader(ResourceLoader resourceLoader) {
         persistenceUnitManager.setResourceLoader(resourceLoader);
     }
 
     @Override
     public PersistenceUnitInfo getPersistenceUnitInfo() {
         return internalFactoryBean.getPersistenceUnitInfo();
     }
 
     @Override
     public String getPersistenceUnitName() {
         return internalFactoryBean.getPersistenceUnitName();
     }
 
     @Override
     public DataSource getDataSource() {
         PersistenceUnitInfo pui = internalFactoryBean.getPersistenceUnitInfo();
         if (internalFactoryBean.getPersistenceUnitInfo() != null) {
             return (pui.getJtaDataSource() != null ?
                     pui.getJtaDataSource() :
                     pui.getNonJtaDataSource());
         }
         return (persistenceUnitManager.getDefaultJtaDataSource() != null ?
                 persistenceUnitManager.getDefaultJtaDataSource() :
                 this.persistenceUnitManager.getDefaultDataSource());
     }
 
     @Override
     public JpaDialect getJpaDialect() {
         return internalFactoryBean.getJpaDialect();
     }
 
     @Override
     public PersistenceProvider getPersistenceProvider() {
         return internalFactoryBean.getPersistenceProvider();
     }
 
     @Override
     public DataAccessException translateExceptionIfPossible(RuntimeException ex) {
         return internalFactoryBean.translateExceptionIfPossible(ex);
     }
 
     /**
      * Specifies a List of class names which should be loaded into the resulting EntityManagerFactory as managed
      * JPA classes.
      *
      * @param managedClassNames the List of managed class names to set on this factory bean
      */
     public void setManagedClassNames(List<String> managedClassNames) {
         if (managedClassNames == null) {
             managedClassNames = new ArrayList<String>();
         }
         if (LOG.isInfoEnabled()) {
             LOG.info(getPersistenceUnitName() + ": Setting Managed Class Names JPA:\n" + managedClassNames);
         }
         this.managedClassNames = managedClassNames;
     }
 
     /**
      * 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.</p>
      *
      * @param emInterface the {@link EntityManager} interface to use
      *
      * @see JpaVendorAdapter#getEntityManagerInterface()
      * @see EntityManagerFactoryInfo#getEntityManagerInterface()
      */
     public void setEntityManagerInterface(Class<? extends EntityManager> emInterface) {
         internalFactoryBean.setEntityManagerInterface(emInterface);
     }
 
     /**
      * 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.</p>
      *
      * @param emfInterface the {@link EntityManagerFactory} interface to use
      *
      * @see JpaVendorAdapter#getEntityManagerFactoryInterface()
      */
     public void setEntityManagerFactoryInterface(Class<? extends EntityManagerFactory> emfInterface) {
         internalFactoryBean.setEntityManagerFactoryInterface(emfInterface);
     }
 
     /**
      * 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]".</p>
      *
      * @return the map of JPA properties
      */
     public Map<String, Object> getJpaPropertyMap() {
         return internalFactoryBean.getJpaPropertyMap();
     }
 
     /**
      * 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.</p>
      *
      * @param jpaProperties map of JPA properties to set
      *
      * @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(Map<String, ?> jpaProperties) {
         internalFactoryBean.setJpaPropertyMap(jpaProperties);
     }
 
     /**
      * 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.</p>
      *
      * @param jpaProperties the properties to set
      *
      * @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) {
         internalFactoryBean.setJpaProperties(jpaProperties);
     }
 
     /**
      * 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.</p>
      *
      * @param persistenceUnitName the name of the persistence unit
      *
      * @see javax.persistence.Persistence#createEntityManagerFactory(String)
      */
     public void setPersistenceUnitName(String persistenceUnitName) {
         internalFactoryBean.setPersistenceUnitName(persistenceUnitName);
         persistenceUnitManager.setDefaultPersistenceUnitName(persistenceUnitName);
     }
 
     /**
      * 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>
      *
      * @param packagesToScan one or more base packages to search, analogous to Spring's component-scan configuration for
      *        regular Spring components
      *
      * @see {@link DefaultPersistenceUnitManager#setPackagesToScan(String...)}
      */
     public void setPackagesToScan(String... packagesToScan) {
         if (LOG.isInfoEnabled()) {
             LOG.info(getPersistenceUnitName() + ": Setting Packages to Scan for JPA Annotations:\n"
                 + Arrays.deepToString(packagesToScan));
         }
         persistenceUnitManager.setPackagesToScan(packagesToScan);
 		converterPackageNames = Arrays.asList(packagesToScan);
     }
 
     /**
      * Specify one or more mapping resources (equivalent to {@code &lt;mapping-file&gt;} 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>
      *
      * @param mappingResources one or more mapping resources to use
      *
      * @see {@link DefaultPersistenceUnitManager#setMappingResources(String...)}
      */
     public void setMappingResources(String... mappingResources) {
         persistenceUnitManager.setMappingResources(mappingResources);
     }
 
     /**
      * 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>
      *
      * @param dataSource the DataSource to use for this EntityManagerFactory
      *
      * @see javax.persistence.spi.PersistenceUnitInfo#getNonJtaDataSource()
      * @see {@link DefaultPersistenceUnitManager#setDefaultDataSource(javax.sql.DataSource)}
      */
     public void setDataSource(DataSource dataSource) {
         persistenceUnitManager.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 {@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>
      *
      * @param jtaDataSource the JTA-enabled DataSource to use for this EntityManagerFactory
      *
      * @see javax.persistence.spi.PersistenceUnitInfo#getJtaDataSource()
      * @see {@link DefaultPersistenceUnitManager#setDefaultJtaDataSource(javax.sql.DataSource)}
      */
     public void setJtaDataSource(DataSource jtaDataSource) {
         persistenceUnitManager.setDefaultJtaDataSource(jtaDataSource);
     }
 
     /**
      * 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).
      *
      * @param persistenceProvider the PersistenceProvider to set
      *
      * @see JpaVendorAdapter#getPersistenceProvider()
      * @see javax.persistence.spi.PersistenceProvider
      * @see javax.persistence.Persistence
      */
     public void setPersistenceProvider(PersistenceProvider persistenceProvider) {
         this.internalFactoryBean.setPersistenceProvider(persistenceProvider);
     }
 
     /**
      * 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.
      *
      * @param jpaDialect the JPA dialect to set
      *
      * @see EntityManagerFactoryInfo#getJpaDialect()
      */
     public void setJpaDialect(JpaDialect jpaDialect) {
         this.internalFactoryBean.setJpaDialect(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.
      *
      * @param jpaVendorAdapter the JpaVendorAdapter to set
      */
     public void setJpaVendorAdapter(JpaVendorAdapter jpaVendorAdapter) {
         this.internalFactoryBean.setJpaVendorAdapter(jpaVendorAdapter);
     }
 
     /**
      * Set the PersistenceUnitPostProcessors to be applied to the * PersistenceUnitInfo used for creating this
      * EntityManagerFactory. Note that if executed before {@link #afterPropertiesSet()} then this factory bean may
      * introduce it's own post processor instances. If invoked after, then this method will override internally
      * configured post processors.
      *
      * <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>
      *
      * @param postProcessors one or more post processors to set
      */
     public void setPersistenceUnitPostProcessors(PersistenceUnitPostProcessor... postProcessors) {
         // persistence unit post processors will get applied to the internal factory bean during afterPropertiesSet(),
         // this allows us to add our own internal post processor to the list)
         this.persistenceUnitPostProcessors = new ArrayList<PersistenceUnitPostProcessor>(Arrays.asList(postProcessors));
     }
 
     private final class InternalPersistenceUnitPostProcessor implements PersistenceUnitPostProcessor {
 
 		private final TypeFilter converterAnnotationTypeFilter = new AnnotationTypeFilter(Converter.class);
 		private ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
 		private static final String ENTITY_CLASS_RESOURCE_PATTERN = "/**/*.class";
 
         @Override
         public void postProcessPersistenceUnitInfo(MutablePersistenceUnitInfo pui) {
             pui.setExcludeUnlistedClasses(DEFAULT_EXCLUDE_UNLISTED_CLASSES);
 			processConverterPackages(pui);
             for (String managedClassName : getManagedClassNames()) {
                 pui.addManagedClassName(managedClassName);
             }
         }
 
 		private void processConverterPackages(MutablePersistenceUnitInfo pui) {
 			if (converterPackageNames != null) {
 				for (String converterPackage : converterPackageNames) {
 					// Code below lifted and modified from Spring's DefaultPersistenceUnitManager
 					try {
 						String pattern = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX
 								+ ClassUtils.convertClassNameToResourcePath(converterPackage)
 								+ ENTITY_CLASS_RESOURCE_PATTERN;
 						if (LOG.isInfoEnabled()) {
 							LOG.info(getPersistenceUnitName() + ": Scanning for JPA @Converter annotations in: "
 									+ pattern);
 						}
 						Resource[] resources = this.resourcePatternResolver.getResources(pattern);
 						MetadataReaderFactory readerFactory = new CachingMetadataReaderFactory(
 								this.resourcePatternResolver);
 						for (Resource resource : resources) {
 							if (!resource.isReadable()) {
 								continue;
 							}
 							if (LOG.isDebugEnabled()) {
 								LOG.debug(getPersistenceUnitName() + ": Found Matching Resource: " + resource);
 							}
 							MetadataReader reader = readerFactory.getMetadataReader(resource);
 							String className = reader.getClassMetadata().getClassName();
 							if (!pui.getManagedClassNames().contains(className)
 									&& converterAnnotationTypeFilter.match(reader, readerFactory)) {
 								pui.addManagedClassName(className);
 								if (LOG.isDebugEnabled()) {
 									LOG.debug(getPersistenceUnitName()
 											+ ": Registering Converter in JPA Persistence Unit: " + className);
 								}
 							}
 						}
 					} catch (IOException ex) {
 						throw new PersistenceException("Failed to scan classpath converters in package: "
 								+ converterPackage, ex);
 					}
 				}
 			}
 		}
     }
 }