persistenceannotationbeanpostprocessor.java

spring api 源代码

/*
 * Copyright 2002-2007 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.support;

import java.beans.PropertyDescriptor;
import java.lang.reflect.AccessibleObject;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import javax.naming.NamingException;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceContext;
import javax.persistence.PersistenceContextType;
import javax.persistence.PersistenceProperty;
import javax.persistence.PersistenceUnit;

import org.springframework.beans.BeansException;
import org.springframework.beans.PropertyValues;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.BeanFactoryUtils;
import org.springframework.beans.factory.ListableBeanFactory;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessor;
import org.springframework.jndi.JndiLocatorSupport;
import org.springframework.orm.jpa.EntityManagerFactoryInfo;
import org.springframework.orm.jpa.EntityManagerFactoryUtils;
import org.springframework.orm.jpa.ExtendedEntityManagerCreator;
import org.springframework.orm.jpa.SharedEntityManagerCreator;
import org.springframework.util.ObjectUtils;
import org.springframework.util.ReflectionUtils;

/**
 * BeanPostProcessor that processes {@link javax.persistence.PersistenceUnit}
 * and {@link javax.persistence.PersistenceContext} annotations, for injection of
 * the corresponding JPA resources {@link javax.persistence.EntityManagerFactory}
 * and {@link javax.persistence.EntityManager}. Any such annotated fields or methods
 * in any Spring-managed object will automatically be injected.
 *
 * <p>This post-processor will inject sub-interfaces of <code>EntityManagerFactory</code>
 * and <code>EntityManager</code> if the annotated fields or methods are declared as such.
 * The actual type will be verified early, with the exception of a shared ("transactional")
 * <code>EntityManager</code> reference, where type mismatches might be detected as late
 * as on the first actual invocation.
 *
 * <p>Note: In the present implementation, PersistenceAnnotationBeanPostProcessor
 * only supports <code>@PersistenceUnit</code> and <code>@PersistenceContext</code>
 * with the "unitName" attribute, or no attribute at all (for the default unit).
 * If those annotations are present with the "name" attribute at the class level,
 * they will simply be ignored, since those only serve as deployment hint
 * (as per the Java EE 5 specification).
 *
 * <p>This post-processor can either obtain EntityManagerFactory beans defined
 * in the Spring application context (the default), or obtain EntityManagerFactory
 * references from JNDI ("persistence unit references"). In the bean case,
 * the persistence unit name will be matched against the actual deployed unit,
 * with the bean name used as fallback unit name if no deployed name found.
 * Typically, Spring's {@link org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean}
 * will be used for setting up such EntityManagerFactory beans. Alternatively,
 * such beans may also be obtained from JNDI, e.g. using the <code>jee:jndi-lookup</code>
 * XML configuration element (with the bean name matching the requested unit name).
 * In both cases, the post-processor definition will look as simple as this:
 *
 * <pre class="code">
 * &lt;bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"/&gt;</pre>
 *
 * In the JNDI case, specify the corresponding JNDI names in this post-processor's
 * {@link #setPersistenceUnits "persistenceUnits" map}, typically with matching
 * <code>persistence-unit-ref</code> entries in the Java EE deployment descriptor.
 * By default, those names are considered as resource references (according to the
 * Java EE resource-ref convention), located underneath the "java:comp/env/" namespace.
 * For example:
 *
 * <pre class="code">
 * &lt;bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"&gt;
 *   &lt;property name="persistenceUnits"&gt;
 *     &lt;map/gt;
 *       &lt;entry key="unit1" value="persistence/unit1"/&gt;
 *       &lt;entry key="unit2" value="persistence/unit2"/&gt;
 *     &lt;/map/gt;
 *   &lt;/property&gt;
 * &lt;/bean&gt;</pre>
 *
 * In this case, the specified persistence units will always be resolved in JNDI
 * rather than as Spring-defined beans. The entire persistence unit deployment,
 * including the weaving of persistent classes, is then up to the Java EE server.
 * Persistence contexts (i.e. EntityManager references) will be built based on
 * those server-provided EntityManagerFactory references, using Spring's own
 * transaction synchronization facilities for transactional EntityManager handling
 * (typically with Spring's <code>@Transactional</code> annotation for demarcation
 * and {@link org.springframework.transaction.jta.JtaTransactionManager} as backend).
 *
 * <p>If you prefer the Java EE server's own EntityManager handling, specify entries
 * in this post-processor's {@link #setPersistenceContexts "persistenceContexts" map}
 * (or {@link #setExtendedPersistenceContexts "extendedPersistenceContexts" map},
 * typically with matching <code>persistence-context-ref</code> entries in the
 * Java EE deployment descriptor. For example:
 *
 * <pre class="code">
 * &lt;bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor"&gt;
 *   &lt;property name="persistenceContexts"&gt;
 *     &lt;map/gt;
 *       &lt;entry key="unit1" value="persistence/context1"/&gt;
 *       &lt;entry key="unit2" value="persistence/context2"/&gt;
 *     &lt;/map/gt;
 *   &lt;/property&gt;
 * &lt;/bean&gt;</pre>
 *
 * If the application only obtains EntityManager references in the first place,
 * this is all you need to specify. If you need EntityManagerFactory references
 * as well, specify entries for both "persistenceUnits" and "persistenceContexts",
 * pointing to matching JNDI locations.
 *
 * <p><b>NOTE: In general, do not inject EXTENDED EntityManagers into STATELESS beans,
 * i.e. do not use <code>@PersistenceContext</code> with type <code>EXTENDED</code> in
 * Spring beans defined with scope 'singleton' (Spring's default scope).</b>
 * Extended EntityManagers are <i>not</i> thread-safe, hence they must not be used
 * in concurrently accessed beans (which Spring-managed singletons usually are).
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @since 2.0
 * @see javax.persistence.PersistenceUnit
 * @see javax.persistence.PersistenceContext
 */
public class PersistenceAnnotationBeanPostProcessor extends JndiLocatorSupport
		implements InstantiationAwareBeanPostProcessor, BeanFactoryAware {

	private Map<String, String> persistenceUnits;

	private Map<String, String> persistenceContexts;

	private Map<String, String> extendedPersistenceContexts;

	private String defaultPersistenceUnitName = "";

	private ListableBeanFactory beanFactory;

	private final Map<Class<?>, List<AnnotatedMember>> annotationMetadataCache =
			new HashMap<Class<?>, List<AnnotatedMember>>();


	public PersistenceAnnotationBeanPostProcessor() {
		setResourceRef(true);
	}


	/**
	 * Specify the persistence units for EntityManagerFactory lookups,
	 * as a Map from persistence unit name to persistence unit JNDI name
	 * (which needs to resolve to an EntityManagerFactory instance).
	 * <p>JNDI names specified here should refer to <code>persistence-unit-ref</code>
	 * entries in the Java EE deployment descriptor, matching the target persistence unit.
	 * <p>In case of no unit name specified in the annotation, the specified value
	 * for the {@link #setDefaultPersistenceUnitName default persistence unit}
	 * will be taken (by default, the value mapped to the empty String),
	 * or simply the single persistence unit if there is only one.
	 * <p>This is mainly intended for use in a Java EE 5 environment, with all
	 * lookup driven by the standard JPA annotations, and all EntityManagerFactory
	 * references obtained from JNDI. No separate EntityManagerFactory bean
	 * definitions are necessary in such a scenario.
	 * <p>If no corresponding "persistenceContexts"/"extendedPersistenceContexts"
	 * are specified, <code>@PersistenceContext</code> will be resolved to
	 * EntityManagers built on top of the EntityManagerFactory defined here.
	 * Note that those will be Spring-managed EntityManagers, which implement
	 * transaction synchronization based on Spring's facilities.
	 * If you prefer the Java EE 5 server's own EntityManager handling,
	 * specify corresponding "persistenceContexts"/"extendedPersistenceContexts".
	 */
	public void setPersistenceUnits(Map<String, String> persistenceUnits) {
		this.persistenceUnits = persistenceUnits;
	}

	/**
	 * Specify the <i>transactional</i> persistence contexts for EntityManager lookups,
	 * as a Map from persistence unit name to persistence context JNDI name
	 * (which needs to resolve to an EntityManager instance).
	 * <p>JNDI names specified here should refer to <code>persistence-context-ref</code>
	 * entries in the Java EE deployment descriptors, matching the target persistence unit
	 * and being set up with persistence context type <code>Transaction</code>.
	 * <p>In case of no unit name specified in the annotation, the specified value
	 * for the {@link #setDefaultPersistenceUnitName default persistence unit}
	 * will be taken (by default, the value mapped to the empty String),
	 * or simply the single persistence unit if there is only one.
	 * <p>This is mainly intended for use in a Java EE 5 environment, with all
	 * lookup driven by the standard JPA annotations, and all EntityManager
	 * references obtained from JNDI. No separate EntityManagerFactory bean
	 * definitions are necessary in such a scenario, and all EntityManager
	 * handling is done by the Java EE 5 server itself.
	 */
	public void setPersistenceContexts(Map<String, String> persistenceContexts) {
		this.persistenceContexts = persistenceContexts;
	}

	/**
	 * Specify the <i>extended</i> persistence contexts for EntityManager lookups,
	 * as a Map from persistence unit name to persistence context JNDI name
	 * (which needs to resolve to an EntityManager instance).
	 * <p>JNDI names specified here should refer to <code>persistence-context-ref</code>
	 * entries in the Java EE deployment descriptors, matching the target persistence unit
	 * and being set up with persistence context type <code>Extended</code>.
	 * <p>In case of no unit name specified in the annotation, the specified value
	 * for the {@link #setDefaultPersistenceUnitName default persistence unit}
	 * will be taken (by default, the value mapped to the empty String),
	 * or simply the single persistence unit if there is only one.
	 * <p>This is mainly intended for use in a Java EE 5 environment, with all
	 * lookup driven by the standard JPA annotations, and all EntityManager
	 * references obtained from JNDI. No separate EntityManagerFactory bean
	 * definitions are necessary in such a scenario, and all EntityManager
	 * handling is done by the Java EE 5 server itself.
	 */
	public void setExtendedPersistenceContexts(Map<String, String> extendedPersistenceContexts) {
		this.extendedPersistenceContexts = extendedPersistenceContexts;
	}

	/**
	 * Specify the default persistence unit name, to be used in case
	 * of no unit name specified in an <code>@PersistenceUnit</code> /
	 * <code>@PersistenceContext</code> annotation.
	 * <p>This is mainly intended for lookups in the application context,
	 * indicating the target persistence unit name (typically matching
	 * the bean name), but also applies to lookups in the
	 * {@link #setPersistenceUnits "persistenceUnits"} /
	 * {@link #setPersistenceContexts "persistenceContexts"} /
	 * {@link #setExtendedPersistenceContexts "extendedPersistenceContexts"} map,
	 * avoiding the need for duplicated mappings for the empty String there.
	 * <p>Default is to check for a single EntityManagerFactory bean
	 * in the Spring application context, if any. If there are multiple
	 * such factories, either specify this default persistence unit name
	 * or explicitly refer to named persistence units in your annotations.
	 */
	public void setDefaultPersistenceUnitName(String unitName) {
		this.defaultPersistenceUnitName = (unitName != null ? unitName : "");
	}

	public void setBeanFactory(BeanFactory beanFactory) {
		if (beanFactory instanceof ListableBeanFactory) {
			this.beanFactory = (ListableBeanFactory) beanFactory;
		}
	}


	public Object postProcessBeforeInstantiation(Class beanClass, String beanName) throws BeansException {
		return null;
	}

	public boolean postProcessAfterInstantiation(Object bean, String beanName) throws BeansException {
		List<AnnotatedMember> metadata = findAnnotationMetadata(bean.getClass());
		for (AnnotatedMember member : metadata) {
			member.inject(bean);
		}
		return true;
	}

	public PropertyValues postProcessPropertyValues(
			PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) throws BeansException {

		return pvs;
	}

	public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
		return bean;
	}

	public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
		return bean;
	}


	private List<AnnotatedMember> findAnnotationMetadata(Class clazz) {
		synchronized (this.annotationMetadataCache) {
			List<AnnotatedMember> metadata = this.annotationMetadataCache.get(clazz);
			if (metadata == null) {
				final List<AnnotatedMember> newMetadata = new LinkedList<AnnotatedMember>();
				ReflectionUtils.doWithFields(clazz, new ReflectionUtils.FieldCallback() {
					public void doWith(Field field) {
						addIfPresent(newMetadata, field);
					}
				});
				ReflectionUtils.doWithMethods(clazz, new ReflectionUtils.MethodCallback() {
					public void doWith(Method method) {
						addIfPresent(newMetadata, method);
					}
				});
				metadata = newMetadata;
				this.annotationMetadataCache.put(clazz, metadata);