/*
* Copyright 2010-2012 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.mybatis.spring;
import static org.springframework.transaction.support.TransactionSynchronizationManager.bindResource;
import static org.springframework.transaction.support.TransactionSynchronizationManager.getResource;
import static org.springframework.transaction.support.TransactionSynchronizationManager.isActualTransactionActive;
import static org.springframework.transaction.support.TransactionSynchronizationManager.isSynchronizationActive;
import static org.springframework.transaction.support.TransactionSynchronizationManager.registerSynchronization;
import static org.springframework.transaction.support.TransactionSynchronizationManager.unbindResource;
import static org.springframework.util.Assert.notNull;
import org.apache.ibatis.exceptions.PersistenceException;
import org.apache.ibatis.logging.Log;
import org.apache.ibatis.logging.LogFactory;
import org.apache.ibatis.mapping.Environment;
import org.apache.ibatis.session.ExecutorType;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.mybatis.spring.transaction.SpringManagedTransactionFactory;
import org.springframework.dao.DataAccessException;
import org.springframework.dao.TransientDataAccessResourceException;
import org.springframework.dao.support.PersistenceExceptionTranslator;
import org.springframework.jdbc.datasource.DataSourceUtils;
import org.springframework.transaction.support.TransactionSynchronizationAdapter;
/**
* Handles MyBatis SqlSession life cycle. It can register and get SqlSessions from
* Spring {@code TransactionSynchronizationManager}. Also works if no transaction is active.
*
* @author Hunter Presnall
* @author Eduardo Macarron
*
* @version $Id$
*/
public final class SqlSessionUtils {
private static final Log logger = LogFactory.getLog(SqlSessionUtils.class);
/**
* This class can't be instantiated, exposes static utility methods only.
*/
private SqlSessionUtils() {
// do nothing
}
/**
* Creates a new MyBatis {@code SqlSession} from the {@code SqlSessionFactory}
* provided as a parameter and using its {@code DataSource} and {@code ExecutorType}
*
* @param sessionFactory a MyBatis {@code SqlSessionFactory} to create new sessions
* @return a MyBatis {@code SqlSession}
* @throws TransientDataAccessResourceException if a transaction is active and the
* {@code SqlSessionFactory} is not using a {@code SpringManagedTransactionFactory}
*/
public static SqlSession getSqlSession(SqlSessionFactory sessionFactory) {
ExecutorType executorType = sessionFactory.getConfiguration().getDefaultExecutorType();
return getSqlSession(sessionFactory, executorType, null);
}
/**
* Gets an SqlSession from Spring Transaction Manager or creates a new one if needed.
* Tries to get a SqlSession out of current transaction. If there is not any, it creates a new one.
* Then, it synchronizes the SqlSession with the transaction if Spring TX is active and
* <code>SpringManagedTransactionFactory</code> is configured as a transaction manager.
*
* @param sessionFactory a MyBatis {@code SqlSessionFactory} to create new sessions
* @param executorType The executor type of the SqlSession to create
* @param exceptionTranslator Optional. Translates SqlSession.commit() exceptions to Spring exceptions.
* @throws TransientDataAccessResourceException if a transaction is active and the
* {@code SqlSessionFactory} is not using a {@code SpringManagedTransactionFactory}
* @see SpringManagedTransactionFactory
*/
public static SqlSession getSqlSession(SqlSessionFactory sessionFactory, ExecutorType executorType, PersistenceExceptionTranslator exceptionTranslator) {
notNull(sessionFactory, "No SqlSessionFactory specified");
notNull(executorType, "No ExecutorType specified");
SqlSessionHolder holder = (SqlSessionHolder) getResource(sessionFactory);
if (holder != null && holder.isSynchronizedWithTransaction()) {
if (holder.getExecutorType() != executorType) {
throw new TransientDataAccessResourceException("Cannot change the ExecutorType when there is an existing transaction");
}
holder.requested();
if (logger.isDebugEnabled()) {
logger.debug("Fetched SqlSession [" + holder.getSqlSession() + "] from current transaction");
}
return holder.getSqlSession();
}
if (logger.isDebugEnabled()) {
logger.debug("Creating a new SqlSession");
}
SqlSession session = sessionFactory.openSession(executorType);
// Register session holder if synchronization is active (i.e. a Spring TX is active)
//
// Note: The DataSource used by the Environment should be synchronized with the
// transaction either through DataSourceTxMgr or another tx synchronization.
// Further assume that if an exception is thrown, whatever started the transaction will
// handle closing / rolling back the Connection associated with the SqlSession.
if (isSynchronizationActive()) {
Environment environment = sessionFactory.getConfiguration().getEnvironment();
if (environment.getTransactionFactory() instanceof SpringManagedTransactionFactory) {
if (logger.isDebugEnabled()) {
logger.debug("Registering transaction synchronization for SqlSession [" + session + "]");
}
holder = new SqlSessionHolder(session, executorType, exceptionTranslator);
bindResource(sessionFactory, holder);
registerSynchronization(new SqlSessionSynchronization(holder, sessionFactory));
holder.setSynchronizedWithTransaction(true);
holder.requested();
} else {
if (getResource(environment.getDataSource()) == null) {
if (logger.isDebugEnabled()) {
logger.debug("SqlSession [" + session + "] was not registered for synchronization because DataSource is not transactional");
}
} else {
throw new TransientDataAccessResourceException(
"SqlSessionFactory must be using a SpringManagedTransactionFactory in order to use Spring transaction synchronization");
}
}
} else {
if (logger.isDebugEnabled()) {
logger.debug("SqlSession [" + session + "] was not registered for synchronization because synchronization is not active");
}
}
return session;
}
/**
* Checks if {@code SqlSession} passed as an argument is managed by Spring {@code TransactionSynchronizationManager}
* If it is not, it closes it, otherwise it just updates the reference counter and
* lets Spring call the close callback when the managed transaction ends
*
* @param session
* @param sessionFactory
*/
public static void closeSqlSession(SqlSession session, SqlSessionFactory sessionFactory) {
notNull(session, "No SqlSession specified");
notNull(sessionFactory, "No SqlSessionFactory specified");
SqlSessionHolder holder = (SqlSessionHolder) getResource(sessionFactory);
if ((holder != null) && (holder.getSqlSession() == session)) {
if (logger.isDebugEnabled()) {
logger.debug("Releasing transactional SqlSession [" + session + "]");
}
holder.released();
} else {
if (logger.isDebugEnabled()) {
logger.debug("Closing non transactional SqlSession [" + session + "]");
}
session.close();
}
}
/**
* Returns if the {@code SqlSession} passed as an argument is being managed by Spring
*
* @param session a MyBatis SqlSession to check
* @param sessionFactory the SqlSessionFactory which the SqlSession was built with
* @return true if session is transactional, otherwise false
*/
public static boolean isSqlSessionTransactional(SqlSession session, SqlSessionFactory sessionFactory) {
notNull(session, "No SqlSession specified");
notNull(sessionFactory, "No SqlSessionFactory specified");
SqlSessionHolder holder = (SqlSessionHolder) getResource(sessionFactory);
return (holder != null) && (holder.getSqlSession() == session);
}
/**
* Callback for cleaning up resources. It cleans TransactionSynchronizationManager and
* also commits and closes the {@code SqlSession}.
* It assumes that {@code Connection} life cycle will be managed by
* {@code DataSourceTransactionManager} or {@code JtaTransactionManager}
*/
private static final class SqlSessionSynchronization extends TransactionSynchronizationAdapter {
private final SqlSessionHolder holder;
private final SqlSessionFactory sessionFactory;
public SqlSessionSynchronization(SqlSessionHolder holder, SqlSessionFactory sessionFactory) {
notNull(holder, "Parameter 'holder' must be not null");
notNull(sessionFactory, "Parameter 'sessionFactory' must be not null");
this.holder = holder;
this.sessionFactory = sessionFactory;
}
/**
* {@inheritDoc}
*/
@Override
public int getOrder() {
// order right before any Connection synchronization
return DataSourceUtils.CONNECTION_SYNCHRONIZATION_ORDER - 1;
}
/**
* {@inheritDoc}
*/
@Override
public void suspend() {
unbindResource(this.sessionFactory);
}
/**
* {@inheritDoc}
*/
@Override
public void resume() {
bindResource(this.sessionFactory, this.holder);
}
/**
* {@inheritDoc}
*/
@Override
public void beforeCommit(boolean readOnly) {
// Flush BATCH statements so they are actually executed before the connection is committed.
// If there is no tx active data will be rolled back so there is no need to flush batches
if (this.holder.getExecutorType() == ExecutorType.BATCH && isActualTransactionActive()) {
try {
if (logger.isDebugEnabled()) {
logger.debug("Transaction synchronization flushing SqlSession [" + this.holder.getSqlSession() + "]");
}
this.holder.getSqlSession().flushStatements();
} catch (PersistenceException p) {
if (this.holder.getPersistenceExceptionTranslator() != null) {
DataAccessException translated = this.holder.getPersistenceExceptionTranslator().translateExceptionIfPossible(p);
if (translated != null) {
throw translated;
}
}
throw p;
}
}
}
/**
* {@inheritDoc}
*/
@Override
public void afterCompletion(int status) {
// Unbind the SqlSession from tx synchronization
// Note, commit/rollback is needed to ensure 2nd level cache is properly updated
// SpringTransaction will no-op the connection commit/rollback
try {
// Do not call commit unless there is really a transaction;
// no need to commit if just tx synchronization is active but no transaction was started
if (isActualTransactionActive()) {
switch (status) {
case STATUS_COMMITTED:
if (logger.isDebugEnabled()) {
logger.debug("Transaction synchronization committing SqlSession [" + this.holder.getSqlSession() + "]");
}
holder.getSqlSession().commit();
break;
case STATUS_ROLLED_BACK:
if (logger.isDebugEnabled()) {
logger.debug("Transaction synchronization rolling back SqlSession [" + this.holder.getSqlSession() + "]");
}
holder.getSqlSession().rollback();
break;
default:
if (logger.isDebugEnabled()) {
logger.debug("Transaction synchronization ended with unknown status for SqlSession [" + this.holder.getSqlSession() + "]");
}
}
}
} finally {
if (!holder.isOpen()) {
unbindResource(sessionFactory);
try {
if (logger.isDebugEnabled()) {
logger.debug("Transaction synchronization closing SqlSession [" + this.holder.getSqlSession() + "]");
}
this.holder.getSqlSession().close();
} finally {
this.holder.reset();
}
}
}
}
}
}