001/**
002 *   GRANITE DATA SERVICES
003 *   Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
004 *
005 *   This file is part of the Granite Data Services Platform.
006 *
007 *   Granite Data Services is free software; you can redistribute it and/or
008 *   modify it under the terms of the GNU Lesser General Public
009 *   License as published by the Free Software Foundation; either
010 *   version 2.1 of the License, or (at your option) any later version.
011 *
012 *   Granite Data Services is distributed in the hope that it will be useful,
013 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
014 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
015 *   General Public License for more details.
016 *
017 *   You should have received a copy of the GNU Lesser General Public
018 *   License along with this library; if not, write to the Free Software
019 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
020 *   USA, or see <http://www.gnu.org/licenses/>.
021 */
022package org.granite.tide.seam.lazy;
023
024import java.io.Serializable;
025
026import javax.persistence.EntityManager;
027import javax.persistence.Query;
028
029import org.jboss.seam.Component;
030import org.jboss.seam.Entity;
031
032
033/**
034 * Manager responsible for looking up the EntityManager from Seam for the
035 * passed in SessionManagerName
036 * @author CIngram
037 */
038public class SeamEntityManager extends PersistenceContextManager {
039
040        private String emName = null;
041
042        public SeamEntityManager(String emName) {
043            this.emName = emName;
044        }
045        
046        
047        /**
048         * Attach the passed in entity with the EntityManager retrieved
049         * from Seam.
050         * @param entity
051         * @return The attached entity
052         */
053        @Override
054    public Object fetchEntity(Object entity, String[] fetch) {
055        EntityManager em = (EntityManager) Component.getInstance(emName);
056        if (em == null)
057                    throw new RuntimeException("Could not find entity, EntityManager [" + emName + "] not found");
058        
059        Serializable id = (Serializable)Entity.forClass(entity.getClass()).getIdentifier(entity);
060        if (id == null)
061            return null;
062        
063        if (fetch == null || em.getDelegate().getClass().getName().indexOf(".hibernate.") < 0)
064                return em.find(entity.getClass(), id);
065        
066        for (String f : fetch) {
067                Query q = em.createQuery("select e from " + entity.getClass().getName() + " e left join fetch e." + f + " where e = :entity");
068                q.setParameter("entity", entity);
069                entity = q.getSingleResult();
070        }
071        return entity;
072    }
073}