/*
* Copyright 2010-2013 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.mybatis.spring;
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;
import org.springframework.transaction.support.TransactionSynchronizationManager;
/**
* 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);
private static final String NO_EXECUTOR_TYPE_SPECIFIED = "No ExecutorType specified";
private static final String NO_SQL_SESSION_FACTORY_SPECIFIED = "No SqlSessionFactory specified";
private static final String NO_SQL_SESSION_SPECIFIED = "No SqlSession specified";
/**
* 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_SQL_SESSION_FACTORY_SPECIFIED);
notNull(executorType, NO_EXECUTOR_TYPE_SPECIFIED);
SqlSessionHolder holder = (SqlSessionHolder) TransactionSynchronizationManager.getResource(sessionFactory);
SqlSession session = sessionHolder(executorType, holder);
if (session != null) {
return session;
}
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Creating a new SqlSession");
}
session = sessionFactory.openSession(executorType);
registerSessionHolder(sessionFactory, executorType, exceptionTranslator, session);
return session;
}
/**
* 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.
*
* @param sessionFactory sqlSessionFactory used for registration.
* @param executorType executorType used for registration.
* @param exceptionTranslator persistenceExceptionTranslater used for registration.
* @param session sqlSession used for registration.
*/
private static void registerSessionHolder(SqlSessionFactory sessionFactory, ExecutorType executorType,
PersistenceExceptionTranslator exceptionTranslator, SqlSession session) {
SqlSessionHolder holder;
if (TransactionSynchronizationManager.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);
TransactionSynchronizationManager.bindResource(sessionFactory, holder);
TransactionSynchronizationManager.registerSynchronization(new SqlSessionSynchronization(holder, sessionFactory));
holder.setSynchronizedWithTransaction(true);
holder.requested();
} else {
if (TransactionSynchronizationManager.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");
}
}
}
private static SqlSession sessionHolder(ExecutorType executorType, SqlSessionHolder holder) {
SqlSession session = null;
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");
}
session = holder.getSqlSession();
}
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_SQL_SESSION_SPECIFIED);
notNull(sessionFactory, NO_SQL_SESSION_FACTORY_SPECIFIED);
SqlSessionHolder holder = (SqlSessionHolder) TransactionSynchronizationManager.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_SQL_SESSION_SPECIFIED);
notNull(sessionFactory, NO_SQL_SESSION_FACTORY_SPECIFIED);
SqlSessionHolder holder = (SqlSessionHolder) TransactionSynchronizationManager.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;
private boolean holderActive = true;
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() {
if (this.holderActive) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Transaction synchronization suspending SqlSession [" + this.holder.getSqlSession() + "]");
}
TransactionSynchronizationManager.unbindResource(this.sessionFactory);
}
}
/**
* {@inheritDoc}
*/
@Override
public void resume() {
if (this.holderActive) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Transaction synchronization resuming SqlSession [" + this.holder.getSqlSession() + "]");
}
TransactionSynchronizationManager.bindResource(this.sessionFactory, this.holder);
}
}
/**
* {@inheritDoc}
*/
@Override
public void beforeCommit(boolean readOnly) {
// Connection commit or rollback will be handled by ConnectionSynchronization or
// DataSourceTransactionManager.
// But, do cleanup the SqlSession / Executor, including flushing BATCH statements so
// they are actually executed.
// SpringManagedTransaction will no-op the commit over the jdbc connection
// TODO This updates 2nd level caches but the tx may be rolledback later on!
if (TransactionSynchronizationManager.isActualTransactionActive()) {
try {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Transaction synchronization committing SqlSession [" + this.holder.getSqlSession() + "]");
}
this.holder.getSqlSession().commit();
} 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 beforeCompletion() {
// Issue #18 Close SqlSession and deregister it now
// because afterCompletion may be called from a different thread
if (!this.holder.isOpen()) {
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Transaction synchronization deregistering SqlSession [" + this.holder.getSqlSession() + "]");
}
TransactionSynchronizationManager.unbindResource(sessionFactory);
this.holderActive = false;
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Transaction synchronization closing SqlSession [" + this.holder.getSqlSession() + "]");
}
this.holder.getSqlSession().close();
}
}
/**
* {@inheritDoc}
*/
@Override
public void afterCompletion(int status) {
if (this.holderActive) {
// afterCompletion may have been called from a different thread
// so avoid failing if there is nothing in this one
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Transaction synchronization deregistering SqlSession [" + this.holder.getSqlSession() + "]");
}
TransactionSynchronizationManager.unbindResourceIfPossible(sessionFactory);
this.holderActive = false;
if (LOGGER.isDebugEnabled()) {
LOGGER.debug("Transaction synchronization closing SqlSession [" + this.holder.getSqlSession() + "]");
}
this.holder.getSqlSession().close();
}
this.holder.reset();
}
}
}