    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
    015package org.apache.tapestry5.internal.jpa;
    016
    017import java.io.Serializable;
    018
    019import javax.persistence.EntityManager;
    020
    021import org.apache.tapestry5.annotations.ImmutableSessionPersistedObject;
    022import org.apache.tapestry5.jpa.EntityManagerManager;
    023
    024/**
    025 * Encapsulates a JPA entity name with an entity id.
    026 */
    027@ImmutableSessionPersistedObject
    028public 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}