Java tutorial
/* * Copyright 2002-2017 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.util.HashMap; import java.util.Map; import java.util.Properties; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.beans.BeansException; import org.springframework.beans.factory.BeanFactory; import org.springframework.beans.factory.BeanFactoryAware; import org.springframework.beans.factory.ListableBeanFactory; import org.springframework.lang.Nullable; import org.springframework.util.Assert; import org.springframework.util.CollectionUtils; /** * Base class for any class that needs to access a JPA {@link EntityManagerFactory}, * usually in order to obtain a JPA {@link EntityManager}. Defines common properties. * * @author Juergen Hoeller * @since 2.0 * @see EntityManagerFactoryUtils */ public abstract class EntityManagerFactoryAccessor implements BeanFactoryAware { /** Logger available to subclasses */ protected final Log logger = LogFactory.getLog(getClass()); @Nullable private EntityManagerFactory entityManagerFactory; @Nullable private String persistenceUnitName; private final Map<String, Object> jpaPropertyMap = new HashMap<>(); /** * Set the JPA EntityManagerFactory that should be used to create * EntityManagers. * @see javax.persistence.EntityManagerFactory#createEntityManager() * @see javax.persistence.EntityManagerFactory#createEntityManager(java.util.Map) */ public void setEntityManagerFactory(@Nullable EntityManagerFactory emf) { this.entityManagerFactory = emf; } /** * Return the JPA EntityManagerFactory that should be used to create * EntityManagers. */ @Nullable public EntityManagerFactory getEntityManagerFactory() { return this.entityManagerFactory; } /** * Obtain the EntityManagerFactory for actual use. * @return the EntityManagerFactory (never {@code null}) * @throws IllegalStateException in case of no EntityManagerFactory set * @since 5.0 */ protected final EntityManagerFactory obtainEntityManagerFactory() { EntityManagerFactory emf = getEntityManagerFactory(); Assert.state(emf != null, "No EntityManagerFactory set"); return emf; } /** * Set the name of the persistence unit to access the EntityManagerFactory for. * <p>This is an alternative to specifying the EntityManagerFactory by direct reference, * resolving it by its persistence unit name instead. If no EntityManagerFactory and * no persistence unit name have been specified, a default EntityManagerFactory will * be retrieved through finding a single unique bean of type EntityManagerFactory. * @see #setEntityManagerFactory */ public void setPersistenceUnitName(@Nullable String persistenceUnitName) { this.persistenceUnitName = persistenceUnitName; } /** * Return the name of the persistence unit to access the EntityManagerFactory for, if any. */ @Nullable public String getPersistenceUnitName() { return this.persistenceUnitName; } /** * Specify JPA properties, to be passed into * {@code EntityManagerFactory.createEntityManager(Map)} (if any). * <p>Can be populated with a String "value" (parsed via PropertiesEditor) * or a "props" element in XML bean definitions. * @see javax.persistence.EntityManagerFactory#createEntityManager(java.util.Map) */ public void setJpaProperties(Properties jpaProperties) { CollectionUtils.mergePropertiesIntoMap(jpaProperties, this.jpaPropertyMap); } /** * Specify JPA properties as a Map, to be passed into * {@code EntityManagerFactory.createEntityManager(Map)} (if any). * <p>Can be populated with a "map" or "props" element in XML bean definitions. * @see javax.persistence.EntityManagerFactory#createEntityManager(java.util.Map) */ public void setJpaPropertyMap(@Nullable Map<String, Object> 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. * <p>Useful for specifying entries directly, for example via "jpaPropertyMap[myKey]". */ public Map<String, Object> getJpaPropertyMap() { return this.jpaPropertyMap; } /** * Retrieves an EntityManagerFactory by persistence unit name, if none set explicitly. * Falls back to a default EntityManagerFactory bean if no persistence unit specified. * @see #setPersistenceUnitName */ @Override public void setBeanFactory(BeanFactory beanFactory) throws BeansException { if (getEntityManagerFactory() == null) { if (!(beanFactory instanceof ListableBeanFactory)) { throw new IllegalStateException("Cannot retrieve EntityManagerFactory by persistence unit name " + "in a non-listable BeanFactory: " + beanFactory); } ListableBeanFactory lbf = (ListableBeanFactory) beanFactory; setEntityManagerFactory( EntityManagerFactoryUtils.findEntityManagerFactory(lbf, getPersistenceUnitName())); } } /** * Obtain a new EntityManager from this accessor's EntityManagerFactory. * <p>Can be overridden in subclasses to create specific EntityManager variants. * @return a new EntityManager * @throws IllegalStateException if this accessor is not configured with an EntityManagerFactory * @see javax.persistence.EntityManagerFactory#createEntityManager() * @see javax.persistence.EntityManagerFactory#createEntityManager(java.util.Map) */ protected EntityManager createEntityManager() throws IllegalStateException { EntityManagerFactory emf = obtainEntityManagerFactory(); Map<String, Object> properties = getJpaPropertyMap(); return (!CollectionUtils.isEmpty(properties) ? emf.createEntityManager(properties) : emf.createEntityManager()); } /** * Obtain the transactional EntityManager for this accessor's EntityManagerFactory, if any. * @return the transactional EntityManager, or {@code null} if none * @throws IllegalStateException if this accessor is not configured with an EntityManagerFactory * @see EntityManagerFactoryUtils#getTransactionalEntityManager(javax.persistence.EntityManagerFactory) * @see EntityManagerFactoryUtils#getTransactionalEntityManager(javax.persistence.EntityManagerFactory, java.util.Map) */ @Nullable protected EntityManager getTransactionalEntityManager() throws IllegalStateException { EntityManagerFactory emf = obtainEntityManagerFactory(); return EntityManagerFactoryUtils.getTransactionalEntityManager(emf, getJpaPropertyMap()); } }