source: branches/TaskRewrite/src/plugins/acegi-0.5.1/src/java/org/codehaus/groovy/grails/plugins/springsecurity/GrailsWebApplicationObjectSupport.java @ 58

/* Copyright 2006-2009 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.codehaus.groovy.grails.plugins.springsecurity;

import org.apache.log4j.Logger;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.orm.hibernate3.SessionFactoryUtils;
import org.springframework.orm.hibernate3.SessionHolder;
import org.springframework.transaction.support.TransactionSynchronizationManager;
import org.springframework.web.context.support.WebApplicationObjectSupport;

/**
 * Grails Web Application Object Support.
 *
 * @author T.Yamamoto
 * @author <a href='mailto:beckwithb@studentsonly.com'>Burt Beckwith</a>
 */
public abstract class GrailsWebApplicationObjectSupport extends WebApplicationObjectSupport {

        private final Logger _log = Logger.getLogger(getClass());

        private SessionFactory _sessionFactory;

        /**
         * Dependency injection for Hibernate session factory.
         * @param sessionFactory  the factory
         */
        public void setSessionFactory(final SessionFactory sessionFactory) {
                _sessionFactory = sessionFactory;
        }

        /**
         * Holds the session created or existing session and a flag indicating whether it was
         * existing (so we know whether to close it or not).
         */
        public static class SessionContainer {
                private final Session _session;
                private final boolean _existingSession;

                private SessionContainer(final Session session, final boolean existingSession) {
                        _session = session;
                        _existingSession = existingSession;
                }

                /**
                 * Get the session.
                 * @return  the session
                 */
                public Session getSession() {
                        return _session;
                }
        }

        /**
         * Set up hibernate session.
         * @return  the session container, which holds the session and a boolean indicating if the session was pre-existing
         */
        protected SessionContainer setUpSession() {
                SessionFactory sessionFactory = getSessionFactory();

                Session session;
                boolean existing;
                if (TransactionSynchronizationManager.hasResource(sessionFactory)) {
                        _log.debug("Session already has transaction attached");
                        existing = true;
                        session = ((SessionHolder)TransactionSynchronizationManager.getResource(sessionFactory)).getSession();
                }
                else {
                        _log.debug("Session does not have transaction attached... Creating new one");
                        existing = false;
                        session = SessionFactoryUtils.getSession(sessionFactory, true);
                        SessionHolder sessionHolder = new SessionHolder(session);
                        TransactionSynchronizationManager.bindResource(sessionFactory, sessionHolder);
                }

                return new SessionContainer(session, existing);
        }

        /**
         * Release Session.
         */
        protected void releaseSession(final SessionContainer session) {
                if (session._existingSession) {
                        return;
                }

                SessionFactory sessionFactory = getSessionFactory();
                SessionHolder sessionHolder = (SessionHolder)TransactionSynchronizationManager.unbindResource(sessionFactory);
                SessionFactoryUtils.releaseSession(sessionHolder.getSession(), sessionFactory);
                _log.debug("Session released");
        }

        private SessionFactory getSessionFactory() {
                if (_sessionFactory == null) {
                        // should be set via DI, but for backwards compatibility lookup the standard bean
                        _sessionFactory  = (SessionFactory)getWebApplicationContext().getBean("sessionFactory");
                }
                return _sessionFactory;
        }
}