001    /*
002      GRANITE DATA SERVICES
003      Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004    
005      This file is part of Granite Data Services.
006    
007      Granite Data Services is free software; you can redistribute it and/or modify
008      it under the terms of the GNU Library General Public License as published by
009      the Free Software Foundation; either version 2 of the License, or (at your
010      option) any later version.
011    
012      Granite Data Services is distributed in the hope that it will be useful, but
013      WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014      FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015      for more details.
016    
017      You should have received a copy of the GNU Library General Public License
018      along with this library; if not, see <http://www.gnu.org/licenses/>.
019    */
020    
021    package org.granite.tide.seam.lazy;
022    
023    import java.io.Serializable;
024    
025    import javax.persistence.EntityManager;
026    import javax.persistence.Query;
027    
028    import org.jboss.seam.Component;
029    import org.jboss.seam.Entity;
030    import org.jboss.seam.framework.PersistenceController;
031    
032    
033    /**
034     * Manager responsible for looking up the EntityHome from the Seam context.
035     * @author cingram
036     *
037     */
038    public class PersistenceControllerManager extends PersistenceContextManager {
039        
040        private String controllerName;  
041    
042        public PersistenceControllerManager(String controllerName) {
043            this.controllerName = controllerName;
044        }
045        
046        /**
047         * Attach the passed in entity with the EntityManager stored 
048         * in the EntityHome object.
049         * @param entity
050         * @return the attached hibernate object
051         */
052        @Override
053        public Object fetchEntity(Object entity, String[] fetch) {
054            PersistenceController<?> controller = (PersistenceController<?>)Component.getInstance(controllerName);
055            EntityManager em = (EntityManager)controller.getPersistenceContext();
056            Serializable id = (Serializable)Entity.forClass(entity.getClass()).getIdentifier(entity);
057            if (id == null)
058                return null;
059            
060            if (fetch == null || em.getDelegate().getClass().getName().indexOf(".hibernate.") < 0)
061                    return em.find(entity.getClass(), id);
062            
063            for (String f : fetch) {
064                    Query q = em.createQuery("select e from " + entity.getClass().getName() + " e left join fetch e." + f + " where e = :entity");
065                    q.setParameter("entity", entity);
066                    entity = q.getSingleResult();
067            }
068            return entity;
069        }
070    
071    }