/**

  * Copyright 2008 WebPhotos

  *

  * Licensed under the Apache 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.apache.org/licenses/LICENSE-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 net.sf.webphotos.dao.jpa;

 import java.util.List;

 import javax.persistence.EntityManager;

 import javax.persistence.PersistenceContext;

 import javax.persistence.Query;

 import net.sf.webphotos.entity.HasID;

 /**

  *

  * @author Guilherme L A Silva

  */

 public class WebPhotosDAO<E extends HasID, I> {

     protected EntityManager entityManager;

     private Class<E> entityClass;

     private Class<I> keyClass;

     public WebPhotosDAO(Class<E> entityClass, Class<I> keyClass) {

         this.entityClass = entityClass;

         this.keyClass = keyClass;

     }

     /**

      * Workarround for a rapid migration from RowSet

      *

      * @param query

      * @return

      * @deprecated

      */

     @Deprecated

     public Query createNativeQuery(String query) {

         return entityManager.createNativeQuery(query);

     }

     public E findBy(I id) {

         return entityManager.find(this.entityClass, id);

     }

     public void save(E object) throws Exception {

         if (object.getId() != null && object.equals(entityManager.find(entityClass, object.getId()))) {

             entityManager.merge(object);

         } else {

             entityManager.persist(object);

         }

     }

     public void remove(E object) throws Exception {

         entityManager.remove(object);

         entityManager.flush();

     }

     /**

      * @return the entityManager

      */

     public EntityManager getEntityManager() {

         return entityManager;

     }

     /**

      * @param entityManager the entityManager to set

      */

     @PersistenceContext

     public void setEntityManager(EntityManager entityManager) {

         this.entityManager = entityManager;

     }

     /**

      * Workarround for a rapid migration from RowSet

      *

      * @param query

      * @return

      * @deprecated

      */

     @Deprecated

     public List<Object[]> findByNativeQuery(String query) {

         return createNativeQuery(query).getResultList();

     }

     @SuppressWarnings(value = "unchecked")

     protected List<E> find(String query) {

         return entityManager.createQuery(query).getResultList();

     }

     @SuppressWarnings(value = "unchecked")

     protected List<E> findByNamedQuery(String query) {

         return entityManager.createNamedQuery(query).getResultList();

     }

 }