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     */
022    package org.granite.tide.seam.lazy;
023    
024    import java.io.Serializable;
025    
026    import javax.persistence.EntityManager;
027    import javax.persistence.Query;
028    
029    import org.jboss.seam.Component;
030    import 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     */
038    public 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    }