/**

  * Copyright 2010 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.osedu.org/licenses/ECL-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.kuali.student.common.util.jpa;

 import java.util.Arrays;

 import java.util.Map;

 import java.util.Map.Entry;

 import javax.persistence.EntityManager;

 import javax.persistence.EntityManagerFactory;

 import org.springframework.beans.BeansException;

 import org.springframework.beans.factory.xml.XmlBeanFactory;

 import org.springframework.context.ApplicationContext;

 import org.springframework.context.ApplicationContextAware;

 import org.springframework.context.ApplicationEvent;

 import org.springframework.context.ApplicationListener;

 import org.springframework.context.event.ContextRefreshedEvent;

 import org.springframework.core.io.ClassPathResource;

 import org.springframework.core.io.FileSystemResource;

 import org.springframework.core.io.Resource;

 import org.springframework.orm.jpa.EntityManagerFactoryUtils;

 import org.springframework.orm.jpa.SharedEntityManagerCreator;

 /**

  * This loads a jpa message beans from a list of message bean files. Only beans

  * of entityType listed will be loaded.

  *

  * Example spring config:

  * 

  *  <bean id="messageload" class="org.kuali.student.common.util.jpa.LoadJpaBeanFileListener">

  *    <property name="loadJpaBean">

  *       <bean class="org.kuali.student.common.util.jpa.LoadJpaBean" />

  *    </property>

  *    <property name="entityClass" value="org.kuali.student.common.messages.entity.MessageEntity" />

  *    <property name="persistenceUnit" value="MessageManagement"/>

  *    <property name="preloadMap">

  *       <map>

  *          <entry key="File1" value="classpath:bean-file1.xml" />

  *          <entry key="File2" value="classpath:bean-file2.xml" />

  *       </map>

  *   </property>

  *   </bean>

  *

  * @author Kuali Student Team

  *

  */

 public class LoadJpaBeanFileListener implements ApplicationListener,

     ApplicationContextAware { 

     private Map<String, String> preloadMap;

     private ApplicationContext applicationContext;

     private LoadJpaBean loadJpaBean;

     private String persistenceUnit;

     private String entityClass;

     private boolean loaded = false;

     @SuppressWarnings("unchecked")

     @Override

     public void onApplicationEvent(ApplicationEvent event) {

         if (event instanceof ContextRefreshedEvent && !loaded) {

             for (Entry<String, String> entry : preloadMap.entrySet()) {

                 String messageFileName = entry.getValue();

                 Resource res;

                 try{

                     if(messageFileName.startsWith("classpath:")){

                         res = new ClassPathResource(messageFileName.substring("classpath:".length()));

                     }else{

                         res = new FileSystemResource(messageFileName);

                     }

                 } catch (Exception e) {

                     throw new RuntimeException(e);

                 }

                 XmlBeanFactory factory = new XmlBeanFactory(res);

                 EntityManagerFactory emf = EntityManagerFactoryUtils

                         .findEntityManagerFactory(applicationContext, persistenceUnit);

                 EntityManager em = SharedEntityManagerCreator

                         .createSharedEntityManager(emf);

                 try {

                     Class messageClazz = Class.forName(entityClass);

                     Object[] beanArray = factory.getBeansOfType(messageClazz).values().toArray();                    

                     loadJpaBean.loadData(Arrays.asList(beanArray), em);

                 } catch (Exception e) {

                     //Log here, need to catch because if errors are thrown then the transaction is left hanging for some reason

                 }

             }

             loaded=true;

         }        

     }

     /**

      * @return the preloadMap

      */

     public Map<String, String> getPreloadMap() {

         return preloadMap;

     }

     /**

      * @param preloadMap

      *            the preloadMap to set

      */

     public void setPreloadMap(Map<String, String> preloadMap) {

         this.preloadMap = preloadMap;

     }

     @Override

     public void setApplicationContext(ApplicationContext applicationContext)

             throws BeansException {

         this.applicationContext = applicationContext;

     }

     /**

      * @return the loadJpaBean

      */

     public LoadJpaBean getLoadJpaBean() {

         return loadJpaBean;

     }

     /**

      * @param loadJpaBean

      *            the loadJpaBean to set

      */

     public void setLoadJpaBean(LoadJpaBean loadJpaBean) {

         this.loadJpaBean = loadJpaBean;

     }

     public String getPersistenceUnit() {

         return persistenceUnit;

     }

     public void setPersistenceUnit(String persistenceUnit) {

         this.persistenceUnit = persistenceUnit;

     }

     public String getEntityClass() {

         return entityClass;

     }

     public void setEntityClass(String entityClass) {

         this.entityClass = entityClass;

     }

 }