/*
* Copyright 2002-2009 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 java.io.IOException;
import javax.jdo.PersistenceManager;
import javax.jdo.PersistenceManagerFactory;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.orm.jdo.PersistenceManagerFactoryUtils;
import org.springframework.orm.jdo.PersistenceManagerHolder;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;
import org.springframework.web.filter.OncePerRequestFilter;
/**
* Servlet 2.3 Filter 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.
*
* <p>This filter makes JDO PersistenceManagers available via the current thread,
* which will be autodetected by transaction managers. It is suitable for service
* layer transactions via {@link org.springframework.orm.jdo.JdoTransactionManager}
* or {@link org.springframework.transaction.jta.JtaTransactionManager} as well
* as for non-transactional read-only execution.
*
* <p>Looks up the PersistenceManagerFactory in Spring's root web application context.
* Supports a "persistenceManagerFactoryBeanName" filter init-param in <code>web.xml</code>;
* the default bean name is "persistenceManagerFactory". Looks up the PersistenceManagerFactory
* on each request, to avoid initialization order issues (when using ContextLoaderServlet,
* the root application context will get initialized <i>after</i> this filter).
*
* @author Juergen Hoeller
* @since 1.1
* @see OpenPersistenceManagerInViewInterceptor
* @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 OpenPersistenceManagerInViewFilter extends OncePerRequestFilter {
public static final String DEFAULT_PERSISTENCE_MANAGER_FACTORY_BEAN_NAME = "persistenceManagerFactory";
private String persistenceManagerFactoryBeanName = DEFAULT_PERSISTENCE_MANAGER_FACTORY_BEAN_NAME;
/**
* Set the bean name of the PersistenceManagerFactory to fetch from Spring's
* root application context. Default is "persistenceManagerFactory".
* @see #DEFAULT_PERSISTENCE_MANAGER_FACTORY_BEAN_NAME
*/
public void setPersistenceManagerFactoryBeanName(String persistenceManagerFactoryBeanName) {
this.persistenceManagerFactoryBeanName = persistenceManagerFactoryBeanName;
}
/**
* Return the bean name of the PersistenceManagerFactory to fetch from Spring's
* root application context.
*/
protected String getPersistenceManagerFactoryBeanName() {
return this.persistenceManagerFactoryBeanName;
}
@Override
protected void doFilterInternal(
HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
throws ServletException, IOException {
PersistenceManagerFactory pmf = lookupPersistenceManagerFactory(request);
boolean participate = false;
if (TransactionSynchronizationManager.hasResource(pmf)) {
// Do not modify the PersistenceManager: just set the participate flag.
participate = true;
}
else {
logger.debug("Opening JDO PersistenceManager in OpenPersistenceManagerInViewFilter");
PersistenceManager pm = PersistenceManagerFactoryUtils.getPersistenceManager(pmf, true);
TransactionSynchronizationManager.bindResource(pmf, new PersistenceManagerHolder(pm));
}
try {
filterChain.doFilter(request, response);
}
finally {
if (!participate) {
PersistenceManagerHolder pmHolder = (PersistenceManagerHolder)
TransactionSynchronizationManager.unbindResource(pmf);
logger.debug("Closing JDO PersistenceManager in OpenPersistenceManagerInViewFilter");
PersistenceManagerFactoryUtils.releasePersistenceManager(pmHolder.getPersistenceManager(), pmf);
}
}
}
/**
* Look up the PersistenceManagerFactory that this filter should use,
* taking the current HTTP request as argument.
* <p>Default implementation delegates to the <code>lookupPersistenceManagerFactory</code>
* without arguments.
* @return the PersistenceManagerFactory to use
* @see #lookupPersistenceManagerFactory()
*/
protected PersistenceManagerFactory lookupPersistenceManagerFactory(HttpServletRequest request) {
return lookupPersistenceManagerFactory();
}
/**
* Look up the PersistenceManagerFactory that this filter should use.
* The default implementation looks for a bean with the specified name
* in Spring's root application context.
* @return the PersistenceManagerFactory to use
* @see #getPersistenceManagerFactoryBeanName
*/
protected PersistenceManagerFactory lookupPersistenceManagerFactory() {
if (logger.isDebugEnabled()) {
logger.debug("Using PersistenceManagerFactory '" + getPersistenceManagerFactoryBeanName() +
"' for OpenPersistenceManagerInViewFilter");
}
WebApplicationContext wac = WebApplicationContextUtils.getRequiredWebApplicationContext(getServletContext());
return wac.getBean(getPersistenceManagerFactoryBeanName(), PersistenceManagerFactory.class);
}
}
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