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.util.Map;
018import java.util.Set;
019
020import javax.persistence.EntityManager;
021import javax.persistence.EntityManagerFactory;
022import javax.persistence.PersistenceContext;
023import javax.persistence.metamodel.EntityType;
024import javax.persistence.metamodel.Metamodel;
025
026import org.apache.tapestry5.ioc.internal.util.InternalUtils;
027import org.apache.tapestry5.jpa.EntityManagerManager;
028import org.apache.tapestry5.jpa.JpaConstants;
029
030public class JpaInternalUtils
031{
032    public static PersistedEntity convertApplicationValueToPersisted(
033            final EntityManagerManager entityManagerManager, final Object newValue)
034    {
035        final EntityManager em = getEntityManagerFactory(entityManagerManager, newValue);
036
037        final EntityManagerFactory emf = em.getEntityManagerFactory();
038
039        final Map<String, Object> properties = emf.getProperties();
040
041        final String persistenceUnitName = (String) properties
042                .get(JpaConstants.PERSISTENCE_UNIT_NAME);
043
044        final Object id = emf.getPersistenceUnitUtil().getIdentifier(newValue);
045
046        return new PersistedEntity(newValue.getClass(), id, persistenceUnitName);
047    }
048
049    private static EntityManager getEntityManagerFactory(
050            final EntityManagerManager entityManagerManager, final Object entity)
051    {
052        final Map<String, EntityManager> entityManagers = entityManagerManager.getEntityManagers();
053
054        for (final EntityManager em : entityManagers.values())
055        {
056            final EntityManagerFactory emf = em.getEntityManagerFactory();
057
058            final Metamodel metamodel = emf.getMetamodel();
059
060            final Set<EntityType<?>> entities = metamodel.getEntities();
061
062            for (final EntityType<?> entityType : entities)
063            {
064                if (entityType.getJavaType().equals(entity.getClass()))
065                {
066                    if (em.contains(entity))
067                    {
068                        return em;
069                    }
070                }
071            }
072        }
073
074        throw new IllegalArgumentException(
075                String.format(
076                        "Failed persisting the entity. The entity '%s' does not belong to any of the existing persistence contexts.",
077                        entity));
078    }
079
080    public static EntityManager getEntityManager(EntityManagerManager entityManagerManager,
081                                                 PersistenceContext annotation)
082    {
083        String unitName = annotation == null ? null : annotation.unitName();
084
085        if (InternalUtils.isNonBlank(unitName))
086            return entityManagerManager.getEntityManager(unitName);
087
088        Map<String, EntityManager> entityManagers = entityManagerManager.getEntityManagers();
089
090        if (entityManagers.size() == 1)
091            return entityManagers.values().iterator().next();
092
093        throw new RuntimeException("Unable to locate a single EntityManager. " +
094                "You must provide the persistence unit name as defined in the persistence.xml using the @PersistenceContext annotation.");
095    }
096}