org.springframework.orm.jdo.support.OpenPersistenceManagerInViewInterceptor Maven / Gradle / Ivy
/*
* Copyright 2002-2005 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.orm.jdo.support;
import javax.jdo.PersistenceManager;
import javax.jdo.PersistenceManagerFactory;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.dao.DataAccessException;
import org.springframework.orm.jdo.PersistenceManagerFactoryUtils;
import org.springframework.orm.jdo.PersistenceManagerHolder;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
/**
* Spring web HandlerInterceptor that binds a JDO PersistenceManager to the
* thread for the entire processing of the request. Intended for the "Open
* PersistenceManager in View" pattern, i.e. to allow for lazy loading in
* web views despite the original transactions already being completed.
*
* This filter works similar to the AOP JdoInterceptor: It just makes JDO
* PersistenceManagers available via the thread. It is suitable for
* non-transactional execution but also for middle tier transactions via
* JdoTransactionManager or JtaTransactionManager. In the latter case,
* PersistenceManagers pre-bound by this filter will automatically be used
* for the transactions.
*
*
In contrast to OpenPersistenceManagerInViewFilter, this interceptor is set
* up in a Spring application context and can thus take advantage of bean wiring.
* It derives from JdoAccessor to inherit common JDO configuration properties.
*
* @author Juergen Hoeller
* @since 1.1
* @see OpenPersistenceManagerInViewFilter
* @see org.springframework.orm.jdo.JdoInterceptor
* @see org.springframework.orm.jdo.JdoTransactionManager
* @see org.springframework.orm.jdo.PersistenceManagerFactoryUtils#getPersistenceManager
* @see org.springframework.transaction.support.TransactionSynchronizationManager
*/
public class OpenPersistenceManagerInViewInterceptor extends HandlerInterceptorAdapter {
/**
* Suffix that gets appended to the PersistenceManagerFactory toString
* representation for the "participate in existing persistence manager
* handling" request attribute.
* @see #getParticipateAttributeName
*/
public static final String PARTICIPATE_SUFFIX = ".PARTICIPATE";
protected final Log logger = LogFactory.getLog(getClass());
private PersistenceManagerFactory persistenceManagerFactory;
/**
* Set the JDO PersistenceManagerFactory that should be used to create
* PersistenceManagers.
*/
public void setPersistenceManagerFactory(PersistenceManagerFactory pmf) {
this.persistenceManagerFactory = pmf;
}
/**
* Return the JDO PersistenceManagerFactory that should be used to create
* PersistenceManagers.
*/
public PersistenceManagerFactory getPersistenceManagerFactory() {
return persistenceManagerFactory;
}
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws DataAccessException {
if (TransactionSynchronizationManager.hasResource(getPersistenceManagerFactory())) {
// do not modify the PersistenceManager: just mark the request accordingly
String participateAttributeName = getParticipateAttributeName();
Integer count = (Integer) request.getAttribute(participateAttributeName);
int newCount = (count != null) ? count.intValue() + 1 : 1;
request.setAttribute(getParticipateAttributeName(), new Integer(newCount));
}
else {
logger.debug("Opening JDO persistence manager in OpenPersistenceManagerInViewInterceptor");
PersistenceManager pm =
PersistenceManagerFactoryUtils.getPersistenceManager(getPersistenceManagerFactory(), true);
TransactionSynchronizationManager.bindResource(
getPersistenceManagerFactory(), new PersistenceManagerHolder(pm));
}
return true;
}
public void afterCompletion(
HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex)
throws DataAccessException {
String participateAttributeName = getParticipateAttributeName();
Integer count = (Integer) request.getAttribute(participateAttributeName);
if (count != null) {
// do not modify the PersistenceManager: just clear the marker
if (count.intValue() > 1) {
request.setAttribute(participateAttributeName, new Integer(count.intValue() - 1));
}
else {
request.removeAttribute(participateAttributeName);
}
}
else {
PersistenceManagerHolder pmHolder = (PersistenceManagerHolder)
TransactionSynchronizationManager.unbindResource(getPersistenceManagerFactory());
logger.debug("Closing JDO persistence manager in OpenPersistenceManagerInViewInterceptor");
PersistenceManagerFactoryUtils.releasePersistenceManager(
pmHolder.getPersistenceManager(), getPersistenceManagerFactory());
}
}
/**
* Return the name of the request attribute that identifies that a request is
* already filtered. Default implementation takes the toString representation
* of the PersistenceManagerFactory instance and appends ".FILTERED".
* @see #PARTICIPATE_SUFFIX
*/
protected String getParticipateAttributeName() {
return getPersistenceManagerFactory().toString() + PARTICIPATE_SUFFIX;
}
}