spring ExtendedEntityManagerCreator 源码
spring ExtendedEntityManagerCreator 代码
文件路径：/spring-orm/src/main/java/org/springframework/orm/jpa/ExtendedEntityManagerCreator.java
/*
* Copyright 2002-2021 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
*
* https://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.Serializable;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import jakarta.persistence.EntityManager;
import jakarta.persistence.EntityManagerFactory;
import jakarta.persistence.EntityTransaction;
import jakarta.persistence.TransactionRequiredException;
import jakarta.persistence.spi.PersistenceUnitInfo;
import jakarta.persistence.spi.PersistenceUnitTransactionType;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.core.Ordered;
import org.springframework.dao.DataAccessException;
import org.springframework.dao.support.PersistenceExceptionTranslator;
import org.springframework.lang.Nullable;
import org.springframework.transaction.support.ResourceHolderSynchronization;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.CollectionUtils;
import org.springframework.util.ConcurrentReferenceHashMap;
/**
* Delegate for creating a variety of {@link jakarta.persistence.EntityManager}
* proxies that follow the JPA spec's semantics for "extended" EntityManagers.
*
* <p>Supports several variants of "extended" EntityManagers:
* in particular, an "application-managed extended EntityManager", as defined
* by {@link jakarta.persistence.EntityManagerFactory#createEntityManager()},
* as well as a "container-managed extended EntityManager", as defined by
* {@link jakarta.persistence.PersistenceContextType#EXTENDED}.
*
* <p>The original difference between "application-managed" and "container-managed"
* was the need for explicit joining of an externally managed transaction through
* the {@link EntityManager#joinTransaction()} method in the "application" case
* versus the automatic joining on each user-level EntityManager operation in the
* "container" case. As of JPA 2.1, both join modes are available with both kinds of
* EntityManagers, so the difference between "application-" and "container-managed"
* is now primarily in the join mode default and in the restricted lifecycle of a
* container-managed EntityManager (i.e. tied to the object that it is injected into).
*
* @author Juergen Hoeller
* @author Rod Johnson
* @author Mark Paluch
* @since 2.0
* @see jakarta.persistence.EntityManagerFactory#createEntityManager()
* @see jakarta.persistence.PersistenceContextType#EXTENDED
* @see jakarta.persistence.EntityManager#joinTransaction()
* @see SharedEntityManagerCreator
*/
public abstract class ExtendedEntityManagerCreator {
private static final Map<Class<?>, Class<?>[]> cachedEntityManagerInterfaces = new ConcurrentReferenceHashMap<>(4);
/**
* Create an application-managed extended EntityManager proxy.
* @param rawEntityManager the raw EntityManager to decorate
* @param emfInfo the EntityManagerFactoryInfo to obtain the JpaDialect
* and PersistenceUnitInfo from
* @return an application-managed EntityManager that can join transactions
* but does not participate in them automatically
*/
public static EntityManager createApplicationManagedEntityManager(
EntityManager rawEntityManager, EntityManagerFactoryInfo emfInfo) {
return createProxy(rawEntityManager, emfInfo, false, false);
}
/**
* Create an application-managed extended EntityManager proxy.
* @param rawEntityManager the raw EntityManager to decorate
* @param emfInfo the EntityManagerFactoryInfo to obtain the JpaDialect
* and PersistenceUnitInfo from
* @param synchronizedWithTransaction whether to automatically join ongoing
* transactions (according to the JPA 2.1 SynchronizationType rules)
* @return an application-managed EntityManager that can join transactions
* but does not participate in them automatically
* @since 4.0
*/
public static EntityManager createApplicationManagedEntityManager(
EntityManager rawEntityManager, EntityManagerFactoryInfo emfInfo, boolean synchronizedWithTransaction) {
return createProxy(rawEntityManager, emfInfo, false, synchronizedWithTransaction);
}
/**
* Create a container-managed extended EntityManager proxy.
* @param rawEntityManager the raw EntityManager to decorate
* @param emfInfo the EntityManagerFactoryInfo to obtain the JpaDialect
* and PersistenceUnitInfo from
* @return a container-managed EntityManager that will automatically participate
* in any managed transaction
*/
public static EntityManager createContainerManagedEntityManager(
EntityManager rawEntityManager, EntityManagerFactoryInfo emfInfo) {
return createProxy(rawEntityManager, emfInfo, true, true);
}
/**
* Create a container-managed extended EntityManager proxy.
* @param emf the EntityManagerFactory to create the EntityManager with.
* If this implements the EntityManagerFactoryInfo interface, the corresponding
* JpaDialect and PersistenceUnitInfo will be detected accordingly.
* @return a container-managed EntityManager that will automatically participate
* in any managed transaction
* @see jakarta.persistence.EntityManagerFactory#createEntityManager()
*/
public static EntityManager createContainerManagedEntityManager(EntityManagerFactory emf) {
return createContainerManagedEntityManager(emf, null, true);
}
/**
* Create a container-managed extended EntityManager proxy.
* @param emf the EntityManagerFactory to create the EntityManager with.
* If this implements the EntityManagerFactoryInfo interface, the corresponding
* JpaDialect and PersistenceUnitInfo will be detected accordingly.
* @param properties the properties to be passed into the {@code createEntityManager}
* call (may be {@code null})
* @return a container-managed EntityManager that will automatically participate
* in any managed transaction
* @see jakarta.persistence.EntityManagerFactory#createEntityManager(java.util.Map)
*/
public static EntityManager createContainerManagedEntityManager(EntityManagerFactory emf, @Nullable Map<?, ?> properties) {
return createContainerManagedEntityManager(emf, properties, true);
}
/**
* Create a container-managed extended EntityManager proxy.
* @param emf the EntityManagerFactory to create the EntityManager with.
* If this implements the EntityManagerFactoryInfo interface, the corresponding
* JpaDialect and PersistenceUnitInfo will be detected accordingly.
* @param properties the properties to be passed into the {@code createEntityManager}
* call (may be {@code null})
* @param synchronizedWithTransaction whether to automatically join ongoing
* transactions (according to the JPA 2.1 SynchronizationType rules)
* @return a container-managed EntityManager that expects container-driven lifecycle
* management but may opt out of automatic transaction synchronization
* @since 4.0
* @see jakarta.persistence.EntityManagerFactory#createEntityManager(java.util.Map)
*/
public static EntityManager createContainerManagedEntityManager(
EntityManagerFactory emf, @Nullable Map<?, ?> properties, boolean synchronizedWithTransaction) {
Assert.notNull(emf, "EntityManagerFactory must not be null");
if (emf instanceof EntityManagerFactoryInfo emfInfo) {
EntityManager rawEntityManager = emfInfo.createNativeEntityManager(properties);
return createProxy(rawEntityManager, emfInfo, true, synchronizedWithTransaction);
}
else {
EntityManager rawEntityManager = (!CollectionUtils.isEmpty(properties) ?
emf.createEntityManager(properties) : emf.createEntityManager());
return createProxy(rawEntityManager, null, null, null, null, true, synchronizedWithTransaction);
}
}
/**
* Actually create the EntityManager proxy.
* @param rawEntityManager raw EntityManager
* @param emfInfo the EntityManagerFactoryInfo to obtain the JpaDialect
* and PersistenceUnitInfo from
* @param containerManaged whether to follow container-managed EntityManager
* or application-managed EntityManager semantics
* @param synchronizedWithTransaction whether to automatically join ongoing
* transactions (according to the JPA 2.1 SynchronizationType rules)
* @return the EntityManager proxy
*/
private static EntityManager createProxy(EntityManager rawEntityManager,
EntityManagerFactoryInfo emfInfo, boolean containerManaged, boolean synchronizedWithTransaction) {
Assert.notNull(emfInfo, "EntityManagerFactoryInfo must not be null");
JpaDialect jpaDialect = emfInfo.getJpaDialect();
PersistenceUnitInfo pui = emfInfo.getPersistenceUnitInfo();
Boolean jta = (pui != null ? pui.getTransactionType() == PersistenceUnitTransactionType.JTA : null);
return createProxy(rawEntityManager, emfInfo.getEntityManagerInterface(),
emfInfo.getBeanClassLoader(), jpaDialect, jta, containerManaged, synchronizedWithTransaction);
}
/**
* Actually create the EntityManager proxy.
* @param rawEm raw EntityManager
* @param emIfc the (potentially vendor-specific) EntityManager
* interface to proxy, or {@code null} for default detection of all interfaces
* @param cl the ClassLoader to use for proxy creation (maybe {@code null})
* @param exceptionTranslator the PersistenceException translator to use
* @param jta whether to create a JTA-aware EntityManager
* (or {@code null} if not known in advance)
* @param containerManaged whether to follow container-managed EntityManager
* or application-managed EntityManager semantics
* @param synchronizedWithTransaction whether to automatically join ongoing
* transactions (according to the JPA 2.1 SynchronizationType rules)
* @return the EntityManager proxy
*/
private static EntityManager createProxy(
EntityManager rawEm, @Nullable Class<? extends EntityManager> emIfc, @Nullable ClassLoader cl,
@Nullable PersistenceExceptionTranslator exceptionTranslator, @Nullable Boolean jta,
boolean containerManaged, boolean synchronizedWithTransaction) {
Assert.notNull(rawEm, "EntityManager must not be null");
Class<?>[] interfaces;
if (emIfc != null) {
interfaces = cachedEntityManagerInterfaces.computeIfAbsent(emIfc, key -> {
if (EntityManagerProxy.class.equals(key)) {
return new Class<?>[] {key};
}
return new Class<?>[] {key, EntityManagerProxy.class};
});
}
else {
interfaces = cachedEntityManagerInterfaces.computeIfAbsent(rawEm.getClass(), key -> {
Set<Class<?>> ifcs = new LinkedHashSet<>(ClassUtils.getAllInterfacesForClassAsSet(key, cl));
ifcs.add(EntityManagerProxy.class);
return ClassUtils.toClassArray(ifcs);
});
}
return (EntityManager) Proxy.newProxyInstance(
(cl != null ? cl : ExtendedEntityManagerCreator.class.getClassLoader()),
interfaces,
new ExtendedEntityManagerInvocationHandler(
rawEm, exceptionTranslator, jta, containerManaged, synchronizedWithTransaction));
}
/**
* InvocationHandler for extended EntityManagers as defined in the JPA spec.
*/
@SuppressWarnings("serial")
private static final class ExtendedEntityManagerInvocationHandler implements InvocationHandler, Serializable {
private static final Log logger = LogFactory.getLog(ExtendedEntityManagerInvocationHandler.class);
private final EntityManager target;
@Nullable
private final PersistenceExceptionTranslator exceptionTranslator;
private final boolean jta;
private final boolean containerManaged;
private final boolean synchronizedWithTransaction;
private ExtendedEntityManagerInvocationHandler(EntityManager target,
@Nullable PersistenceExceptionTranslator exceptionTranslator, @Nullable Boolean jta,
boolean containerManaged, boolean synchronizedWithTransaction) {
this.target = target;
this.exceptionTranslator = exceptionTranslator;
this.jta = (jta != null ? jta : isJtaEntityManager());
this.containerManaged = containerManaged;
this.synchronizedWithTransaction = synchronizedWithTransaction;
}
private boolean isJtaEntityManager() {
try {
this.target.getTransaction();
return false;
}
catch (IllegalStateException ex) {
logger.debug("Cannot access EntityTransaction handle - assuming we're in a JTA environment");
return true;
}
}
@Override
@Nullable
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
// Invocation on EntityManager interface coming in...
switch (method.getName()) {
case "equals":
// Only consider equal when proxies are identical.
return (proxy == args[0]);
case "hashCode":
// Use hashCode of EntityManager proxy.
return hashCode();
case "getTargetEntityManager":
// Handle EntityManagerProxy interface.
return this.target;
case "unwrap":
// Handle JPA 2.0 unwrap method - could be a proxy match.
Class<?> targetClass = (Class<?>) args[0];
if (targetClass == null) {
return this.target;
}
else if (targetClass.isInstance(proxy)) {
return proxy;
}
break;
case "isOpen":
if (this.containerManaged) {
return true;
}
break;
case "close":
if (this.containerManaged) {
throw new IllegalStateException("Invalid usage: Cannot close a container-managed EntityManager");
}
ExtendedEntityManagerSynchronization synch = (ExtendedEntityManagerSynchronization)
TransactionSynchronizationManager.getResource(this.target);
if (synch != null) {
// Local transaction joined - don't actually call close() before transaction completion
synch.closeOnCompletion = true;
return null;
}
break;
case "getTransaction":
if (this.synchronizedWithTransaction) {
throw new IllegalStateException(
"Cannot obtain local EntityTransaction from a transaction-synchronized EntityManager");
}
break;
case "joinTransaction":
doJoinTransaction(true);
return null;
case "isJoinedToTransaction":
// Handle JPA 2.1 isJoinedToTransaction method for the non-JTA case.
if (!this.jta) {
return TransactionSynchronizationManager.hasResource(this.target);
}
break;
}
// Do automatic joining if required. Excludes toString, equals, hashCode calls.
if (this.synchronizedWithTransaction && method.getDeclaringClass().isInterface()) {
doJoinTransaction(false);
}
// Invoke method on current EntityManager.
try {
return method.invoke(this.target, args);
}
catch (InvocationTargetException ex) {
throw ex.getTargetException();
}
}
/**
* Join an existing transaction, if not already joined.
* @param enforce whether to enforce the transaction
* (i.e. whether failure to join is considered fatal)
*/
private void doJoinTransaction(boolean enforce) {
if (this.jta) {
// Let's try whether we're in a JTA transaction.
try {
this.target.joinTransaction();
logger.debug("Joined JTA transaction");
}
catch (TransactionRequiredException ex) {
if (!enforce) {
logger.debug("No JTA transaction to join: " + ex);
}
else {
throw ex;
}
}
}
else {
if (TransactionSynchronizationManager.isSynchronizationActive()) {
if (!TransactionSynchronizationManager.hasResource(this.target) &&
!this.target.getTransaction().isActive()) {
enlistInCurrentTransaction();
}
logger.debug("Joined local transaction");
}
else {
if (!enforce) {
logger.debug("No local transaction to join");
}
else {
throw new TransactionRequiredException("No local transaction to join");
}
}
}
}
/**
* Enlist this application-managed EntityManager in the current transaction.
*/
private void enlistInCurrentTransaction() {
// Resource local transaction, need to acquire the EntityTransaction,
// start a transaction now and enlist a synchronization for commit or rollback later.
EntityTransaction et = this.target.getTransaction();
et.begin();
if (logger.isDebugEnabled()) {
logger.debug("Starting resource-local transaction on application-managed " +
"EntityManager [" + this.target + "]");
}
ExtendedEntityManagerSynchronization extendedEntityManagerSynchronization =
new ExtendedEntityManagerSynchronization(this.target, this.exceptionTranslator);
TransactionSynchronizationManager.bindResource(this.target, extendedEntityManagerSynchronization);
TransactionSynchronizationManager.registerSynchronization(extendedEntityManagerSynchronization);
}
}
/**
* TransactionSynchronization enlisting an extended EntityManager
* with a current Spring transaction.
*/
private static class ExtendedEntityManagerSynchronization
extends ResourceHolderSynchronization<EntityManagerHolder, EntityManager>
implements Ordered {
private final EntityManager entityManager;
@Nullable
private final PersistenceExceptionTranslator exceptionTranslator;
public volatile boolean closeOnCompletion;
public ExtendedEntityManagerSynchronization(
EntityManager em, @Nullable PersistenceExceptionTranslator exceptionTranslator) {
super(new EntityManagerHolder(em), em);
this.entityManager = em;
this.exceptionTranslator = exceptionTranslator;
}
@Override
public int getOrder() {
return EntityManagerFactoryUtils.ENTITY_MANAGER_SYNCHRONIZATION_ORDER - 1;
}
@Override
protected void flushResource(EntityManagerHolder resourceHolder) {
try {
this.entityManager.flush();
}
catch (RuntimeException ex) {
throw convertException(ex);
}
}
@Override
protected boolean shouldReleaseBeforeCompletion() {
return false;
}
@Override
public void afterCommit() {
super.afterCommit();
// Trigger commit here to let exceptions propagate to the caller.
try {
this.entityManager.getTransaction().commit();
}
catch (RuntimeException ex) {
throw convertException(ex);
}
}
@Override
public void afterCompletion(int status) {
try {
super.afterCompletion(status);
if (status != STATUS_COMMITTED) {
// Haven't had an afterCommit call: trigger a rollback.
try {
this.entityManager.getTransaction().rollback();
}
catch (RuntimeException ex) {
throw convertException(ex);
}
}
}
finally {
if (this.closeOnCompletion) {
EntityManagerFactoryUtils.closeEntityManager(this.entityManager);
}
}
}
private RuntimeException convertException(RuntimeException ex) {
DataAccessException dae = (this.exceptionTranslator != null) ?
this.exceptionTranslator.translateExceptionIfPossible(ex) :
EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(ex);
return (dae != null ? dae : ex);
}
}
}
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