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 org.apache.tapestry5.internal.transform.ReadOnlyComponentFieldConduit;
018    import org.apache.tapestry5.jpa.EntityManagerManager;
019    import org.apache.tapestry5.model.MutableComponentModel;
020    import org.apache.tapestry5.plastic.InstanceContext;
021    import org.apache.tapestry5.plastic.PlasticClass;
022    import org.apache.tapestry5.plastic.PlasticField;
023    import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
024    import org.apache.tapestry5.services.transform.TransformationSupport;
025    
026    import javax.persistence.PersistenceContext;
027    
028    public class PersistenceContextWorker implements ComponentClassTransformWorker2
029    {
030        private final EntityManagerManager entityManagerManager;
031    
032        public PersistenceContextWorker(final EntityManagerManager entityManagerManager)
033        {
034            this.entityManagerManager = entityManagerManager;
035        }
036    
037        public void transform(PlasticClass plasticClass, TransformationSupport support, MutableComponentModel model)
038        {
039            for (final PlasticField field : plasticClass
040                    .getFieldsWithAnnotation(PersistenceContext.class))
041            {
042                final PersistenceContext annotation = field.getAnnotation(PersistenceContext.class);
043    
044                field.claim(annotation);
045    
046                field.setConduit(new ReadOnlyComponentFieldConduit(plasticClass.getClassName(), field.getName())
047                {
048                    public Object get(Object instance, InstanceContext context)
049                    {
050                        return JpaInternalUtils.getEntityManager(entityManagerManager, annotation);
051                    }
052                });
053            }
054        }
055    }