/*
* 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.transaction.support;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.transaction.PlatformTransactionManager;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionException;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.TransactionSystemException;
/**
* Template class that simplifies programmatic transaction demarcation and
* transaction exception handling.
*
* <p>The central method is {@link #execute}, supporting transactional code that
* implements the {@link TransactionCallback} interface. This template handles
* the transaction lifecycle and possible exceptions such that neither the
* TransactionCallback implementation nor the calling code needs to explicitly
* handle transactions.
*
* <p>Typical usage: Allows for writing low-level data access objects that use
* resources such as JDBC DataSources but are not transaction-aware themselves.
* Instead, they can implicitly participate in transactions handled by higher-level
* application services utilizing this class, making calls to the low-level
* services via an inner-class callback object.
*
* <p>Can be used within a service implementation via direct instantiation with
* a transaction manager reference, or get prepared in an application context
* and passed to services as bean reference. Note: The transaction manager should
* always be configured as bean in the application context: in the first case given
* to the service directly, in the second case given to the prepared template.
*
* <p>Supports setting the propagation behavior and the isolation level by name,
* for convenient configuration in context definitions.
*
* @author Juergen Hoeller
* @since 17.03.2003
* @see #execute
* @see #setTransactionManager
* @see org.springframework.transaction.PlatformTransactionManager
*/
public class TransactionTemplate extends DefaultTransactionDefinition
implements TransactionOperations, InitializingBean {
/** Logger available to subclasses */
protected final Log logger = LogFactory.getLog(getClass());
private PlatformTransactionManager transactionManager;
/**
* Construct a new TransactionTemplate for bean usage.
* <p>Note: The PlatformTransactionManager needs to be set before
* any <code>execute</code> calls.
* @see #setTransactionManager
*/
public TransactionTemplate() {
}
/**
* Construct a new TransactionTemplate using the given transaction manager.
* @param transactionManager the transaction management strategy to be used
*/
public TransactionTemplate(PlatformTransactionManager transactionManager) {
this.transactionManager = transactionManager;
}
/**
* Construct a new TransactionTemplate using the given transaction manager,
* taking its default settings from the given transaction definition.
* @param transactionManager the transaction management strategy to be used
* @param transactionDefinition the transaction definition to copy the
* default settings from. Local properties can still be set to change values.
*/
public TransactionTemplate(PlatformTransactionManager transactionManager, TransactionDefinition transactionDefinition) {
super(transactionDefinition);
this.transactionManager = transactionManager;
}
/**
* Set the transaction management strategy to be used.
*/
public void setTransactionManager(PlatformTransactionManager transactionManager) {
this.transactionManager = transactionManager;
}
/**
* Return the transaction management strategy to be used.
*/
public PlatformTransactionManager getTransactionManager() {
return this.transactionManager;
}
public void afterPropertiesSet() {
if (this.transactionManager == null) {
throw new IllegalArgumentException("Property 'transactionManager' is required");
}
}
public Object execute(TransactionCallback action) throws TransactionException {
if (this.transactionManager instanceof CallbackPreferringPlatformTransactionManager) {
return ((CallbackPreferringPlatformTransactionManager) this.transactionManager).execute(this, action);
}
else {
TransactionStatus status = this.transactionManager.getTransaction(this);
Object result = null;
try {
result = action.doInTransaction(status);
}
catch (RuntimeException ex) {
// Transactional code threw application exception -> rollback
rollbackOnException(status, ex);
throw ex;
}
catch (Error err) {
// Transactional code threw error -> rollback
rollbackOnException(status, err);
throw err;
}
this.transactionManager.commit(status);
return result;
}
}
/**
* Perform a rollback, handling rollback exceptions properly.
* @param status object representing the transaction
* @param ex the thrown application exception or error
* @throws TransactionException in case of a rollback error
*/
private void rollbackOnException(TransactionStatus status, Throwable ex) throws TransactionException {
logger.debug("Initiating transaction rollback on application exception", ex);
try {
this.transactionManager.rollback(status);
}
catch (TransactionSystemException ex2) {
logger.error("Application exception overridden by rollback exception", ex);
ex2.initApplicationException(ex);
throw ex2;
}
catch (RuntimeException ex2) {
logger.error("Application exception overridden by rollback exception", ex);
throw ex2;
}
catch (Error err) {
logger.error("Application exception overridden by rollback error", ex);
throw err;
}
}
}