001    // Copyright 2008 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.hibernate;
016    
017    import org.apache.tapestry5.internal.services.AbstractSessionPersistentFieldStrategy;
018    import org.apache.tapestry5.services.Request;
019    import org.hibernate.HibernateException;
020    import org.hibernate.Session;
021    
022    import java.io.Serializable;
023    
024    /**
025     * Persists Hibernate entities by storing their id in the session.
026     *
027     * @see org.apache.tapestry5.internal.hibernate.PersistedEntity
028     */
029    public class EntityPersistentFieldStrategy extends AbstractSessionPersistentFieldStrategy
030    {
031        private final Session session;
032    
033        public EntityPersistentFieldStrategy(Session session, Request request)
034        {
035            super("entity:", request);
036    
037            this.session = session;
038        }
039    
040        @Override
041        protected Object convertApplicationValueToPersisted(Object newValue)
042        {
043            try
044            {
045                String entityName = session.getEntityName(newValue);
046                Serializable id = session.getIdentifier(newValue);
047    
048                return new PersistedEntity(entityName, id);
049            }
050            catch (HibernateException ex)
051            {
052                throw new IllegalArgumentException(HibernateMessages.entityNotAttached(newValue), ex);
053            }
054        }
055    
056        @Override
057        protected Object convertPersistedToApplicationValue(Object persistedValue)
058        {
059            PersistedEntity persisted = (PersistedEntity) persistedValue;
060    
061            return persisted.restore(session);
062        }
063    }