    001    // Copyright 2011 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    // http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.internal.jpa;
    016
    017    import java.io.Serializable;
    018
    019    import javax.persistence.EntityManager;
    020
    021    import org.apache.tapestry5.annotations.ImmutableSessionPersistedObject;
    022    import org.apache.tapestry5.jpa.EntityManagerManager;
    023
    024    /**
    025     * Encapsulates a JPA entity name with an entity id.
    026     */
    027    @ImmutableSessionPersistedObject
    028    public class PersistedEntity implements Serializable
    029    {
    030        private static final long serialVersionUID = 897120520279686518L;
    031
    032        private final Class entityClass;
    033
    034        private final Object id;
    035
    036        private final String persistenceUnitName;
    037
    038        public PersistedEntity(final Class entityClass, final Object id,
    039                final String persistenceUnitName)
    040        {
    041            this.entityClass = entityClass;
    042            this.id = id;
    043            this.persistenceUnitName = persistenceUnitName;
    044        }
    045
    046        public Object restore(final EntityManagerManager entityManagerManager)
    047        {
    048            try
    049            {
    050                final EntityManager entityManager = entityManagerManager
    051                        .getEntityManager(persistenceUnitName);
    052
    053                return entityManager.find(entityClass, id);
    054            }
    055            catch (final Exception ex)
    056            {
    057                throw new RuntimeException(String.format(
    058                        "Failed to load session-persisted entity %s(%s): %s", entityClass.getName(),
    059                        id, ex));
    060            }
    061        }
    062
    063        @Override
    064        public String toString()
    065        {
    066            return String.format("<PersistedEntity: %s(%s)>", entityClass.getName(), id);
    067        }
    068    }