/*
* Copyright 2011-2013 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.data.transaction;
import static java.util.Arrays.*;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.transaction.CannotCreateTransactionException;
import org.springframework.transaction.HeuristicCompletionException;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionException;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.UnexpectedRollbackException;
import org.springframework.util.Assert;
/**
* {@link PlatformTransactionManager} implementation that orchestrates transaction creation, commits and rollbacks to a
* list of delegates. Using this implementation assumes that errors causing a transaction rollback will usually happen
* before the transaction completion or during the commit of the most inner {@link PlatformTransactionManager}.
* <p />
* The configured instances will start transactions in the order given and commit/rollback in <em>reverse</em> order,
* which means the {@link PlatformTransactionManager} most likely to break the transaction should be the <em>last</em>
* in the list configured. A {@link PlatformTransactionManager} throwing an exception during commit will automatically
* cause the remaining transaction managers to roll back instead of committing.
*
* @author Michael Hunger
* @author Oliver Gierke
* @since 1.6
*/
public class ChainedTransactionManager implements PlatformTransactionManager {
private final static Logger LOGGER = LoggerFactory.getLogger(ChainedTransactionManager.class);
private final List<PlatformTransactionManager> transactionManagers;
private final SynchronizationManager synchronizationManager;
/**
* Creates a new {@link ChainedTransactionManager} delegating to the given {@link PlatformTransactionManager}s.
*
* @param transactionManagers must not be {@literal null} or empty.
*/
public ChainedTransactionManager(PlatformTransactionManager... transactionManagers) {
this(SpringTransactionSynchronizationManager.INSTANCE, transactionManagers);
}
/**
* Creates a new {@link ChainedTransactionManager} using the given {@link SynchronizationManager} and
* {@link PlatformTransactionManager}s.
*
* @param synchronizationManager must not be {@literal null}.
* @param transactionManagers must not be {@literal null} or empty.
*/
ChainedTransactionManager(SynchronizationManager synchronizationManager,
PlatformTransactionManager... transactionManagers) {
Assert.notNull(synchronizationManager, "SynchronizationManager must not be null!");
Assert.notNull(transactionManagers, "Transaction managers must not be null!");
Assert.isTrue(transactionManagers.length > 0, "At least one PlatformTransactionManager must be given!");
this.synchronizationManager = synchronizationManager;
this.transactionManagers = asList(transactionManagers);
}
/*
* (non-Javadoc)
* @see org.springframework.transaction.PlatformTransactionManager#getTransaction(org.springframework.transaction.TransactionDefinition)
*/
public MultiTransactionStatus getTransaction(TransactionDefinition definition) throws TransactionException {
MultiTransactionStatus mts = new MultiTransactionStatus(transactionManagers.get(0));
if (!synchronizationManager.isSynchronizationActive()) {
synchronizationManager.initSynchronization();
mts.setNewSynchonization();
}
try {
for (PlatformTransactionManager transactionManager : transactionManagers) {
mts.registerTransactionManager(definition, transactionManager);
}
} catch (Exception ex) {
Map<PlatformTransactionManager, TransactionStatus> transactionStatuses = mts.getTransactionStatuses();
for (PlatformTransactionManager transactionManager : transactionManagers) {
try {
if (transactionStatuses.get(transactionManager) != null) {
transactionManager.rollback(transactionStatuses.get(transactionManager));
}
} catch (Exception ex2) {
LOGGER.warn("Rollback exception (" + transactionManager + ") " + ex2.getMessage(), ex2);
}
}
if (mts.isNewSynchonization()) {
synchronizationManager.clearSynchronization();
}
throw new CannotCreateTransactionException(ex.getMessage(), ex);
}
return mts;
}
/*
* (non-Javadoc)
* @see org.springframework.transaction.PlatformTransactionManager#commit(org.springframework.transaction.TransactionStatus)
*/
public void commit(TransactionStatus status) throws TransactionException {
MultiTransactionStatus multiTransactionStatus = (MultiTransactionStatus) status;
boolean commit = true;
Exception commitException = null;
PlatformTransactionManager commitExceptionTransactionManager = null;
for (PlatformTransactionManager transactionManager : reverse(transactionManagers)) {
if (commit) {
try {
multiTransactionStatus.commit(transactionManager);
} catch (Exception ex) {
commit = false;
commitException = ex;
commitExceptionTransactionManager = transactionManager;
}
} else {
// after unsucessfull commit we must try to rollback remaining transaction managers
try {
multiTransactionStatus.rollback(transactionManager);
} catch (Exception ex) {
LOGGER.warn("Rollback exception (after commit) (" + transactionManager + ") " + ex.getMessage(), ex);
}
}
}
if (multiTransactionStatus.isNewSynchonization()) {
synchronizationManager.clearSynchronization();
}
if (commitException != null) {
boolean firstTransactionManagerFailed = commitExceptionTransactionManager == getLastTransactionManager();
int transactionState = firstTransactionManagerFailed ? HeuristicCompletionException.STATE_ROLLED_BACK
: HeuristicCompletionException.STATE_MIXED;
throw new HeuristicCompletionException(transactionState, commitException);
}
}
/*
* (non-Javadoc)
* @see org.springframework.transaction.PlatformTransactionManager#rollback(org.springframework.transaction.TransactionStatus)
*/
public void rollback(TransactionStatus status) throws TransactionException {
Exception rollbackException = null;
PlatformTransactionManager rollbackExceptionTransactionManager = null;
MultiTransactionStatus multiTransactionStatus = (MultiTransactionStatus) status;
for (PlatformTransactionManager transactionManager : reverse(transactionManagers)) {
try {
multiTransactionStatus.rollback(transactionManager);
} catch (Exception ex) {
if (rollbackException == null) {
rollbackException = ex;
rollbackExceptionTransactionManager = transactionManager;
} else {
LOGGER.warn("Rollback exception (" + transactionManager + ") " + ex.getMessage(), ex);
}
}
}
if (multiTransactionStatus.isNewSynchonization()) {
synchronizationManager.clearSynchronization();
}
if (rollbackException != null) {
throw new UnexpectedRollbackException("Rollback exception, originated at (" + rollbackExceptionTransactionManager
+ ") " + rollbackException.getMessage(), rollbackException);
}
}
private <T> Iterable<T> reverse(Collection<T> collection) {
List<T> list = new ArrayList<T>(collection);
Collections.reverse(list);
return list;
}
private PlatformTransactionManager getLastTransactionManager() {
return transactionManagers.get(lastTransactionManagerIndex());
}
private int lastTransactionManagerIndex() {
return transactionManagers.size() - 1;
}
}