/*

  * Copyright 2007-2008 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.core.framework.persistence.jpa;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileOutputStream;

 import java.io.IOException;

 import java.io.ObjectInputStream;

 import java.io.ObjectOutputStream;

 import java.util.Map;

 import javax.persistence.EntityManagerFactory;

 import javax.persistence.spi.PersistenceUnitInfo;

 import org.apache.log4j.Logger;

 import org.hibernate.ejb.Ejb3Configuration;

 import org.hibernate.ejb.HibernatePersistence;

 /*

  * This is a temporary hack until we find a better way to override

  * createContainerEntityManagerFactory(...) below so that we can serialize the

  * configuration and cache the factory.

  */

 public class DevHibernatePersistence extends HibernatePersistence {

         private static final Logger LOG = Logger.getLogger(DevHibernatePersistence.class);

         private String serializationFilename;

         private boolean useSerialization;

         // Caching the factory does increase speed, but then it uses the first set of jpa properties specified rather than jpa properties per factory

         // private static EntityManagerFactory factory = null;

         public EntityManagerFactory createContainerEntityManagerFactory(PersistenceUnitInfo info, Map map) {

                 //if (factory != null) {

                 //        return factory;

                 //}

                 EntityManagerFactory factory = null;                

                 Ejb3Configuration cfg = null;

                 ObjectInputStream in = null;

                 try {

                         if (useSerialization && new File(serializationFilename).exists()) {

                                 in = new ObjectInputStream(new FileInputStream(serializationFilename));

                                 cfg = (Ejb3Configuration) in.readObject();

                         } else {

                                 cfg = configure(info, map);

                         }

                 } catch (Exception e) {

                         LOG.error(e.getMessage(), e);

                 } finally {

                         if (in != null) {

                                 try {

                                         in.close();

                                 } catch (IOException e) {

                                         LOG.error(e.getMessage(), e);

                                 }

                         }

                 }

                 if (cfg != null) {

                         factory = cfg.buildEntityManagerFactory();

                 } else {

                         LOG.error("Error creating Ejb3Configuration");

                 }

                 return factory;

         }

         private Ejb3Configuration configure(PersistenceUnitInfo info, Map map) throws IOException {                

                 Ejb3Configuration configured = new Ejb3Configuration().configure(info, map);

                 if (useSerialization) {

                         ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream(serializationFilename));

                         oos.writeObject(configured);

                         oos.close();

                 }

                 return configured;

         }

         public void setSerializationFilename(String serializationFilename) {

                 this.serializationFilename = serializationFilename;

         }

         public void setUseSerialization(boolean useSerialization) {

                 this.useSerialization = useSerialization;

         }

 }