/*
* Copyright 2008-2014 the original author or authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.kaleidofoundry.core.persistence;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.PersistenceContext;
import javax.persistence.PersistenceUnit;
import org.aspectj.lang.JoinPoint;
import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Pointcut;
import org.aspectj.lang.reflect.FieldSignature;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Aspect use to inject {@link EntityManager} an {@link EntityManagerFactory} in an unmanaged environment :
* <ul>
* <li>lazy initialize when EntityManager field type is "get" (not via getter outside from constructor), and if field have to be yet set
* <li>directly, after constructor call, once all internal initialization are done
* <li>
* </ul>
* Chosen solution : 1. lazy initialize when field is get, outside of the constructor
*
* @author jraduget
*/
@Aspect
public class PersistenceContextAspect {
private static final Logger LOGGER = LoggerFactory.getLogger(PersistenceContextAspect.class);
// map of @Persistence... field injected state
private static final List<Object> _$injectedObjects = Collections.synchronizedList(new ArrayList<Object>());
public PersistenceContextAspect() {
LOGGER.debug("@Aspect(PersistenceContextAspect) new instance");
}
// no need to filter on field modifier here, otherwise you can use private || !public at first get argument
@Pointcut("get(@javax.persistence.PersistenceUnit javax.persistence.EntityManagerFactory *) && if()")
public static boolean trackEntityManagerFactoryField(final JoinPoint jp, final JoinPoint.EnclosingStaticPart esjp) {
LOGGER.debug("@Pointcut(PersistenceContextAspect) - trackEntityManagerFactoryField match");
return true;
}
// no need to filter on field modifier here, otherwise you can use private || !public at first get argument
@Pointcut("get(@javax.persistence.PersistenceContext javax.persistence.EntityManager *) && if()")
public static boolean trackEntityManagerField(final JoinPoint jp, final JoinPoint.EnclosingStaticPart esjp) {
LOGGER.debug("@Pointcut(PersistenceContextAspect) - trackEntityManagerField match");
return true;
}
// track field with ProceedingJoinPoint and annotation information with @annotation(annotation)
@Around("trackEntityManagerFactoryField(jp, esjp) && @annotation(annotation)")
public Object trackEntityManagerFactoryToInject(final JoinPoint jp, final JoinPoint.EnclosingStaticPart esjp, final ProceedingJoinPoint thisJoinPoint,
final PersistenceUnit annotation) throws Throwable {
if (thisJoinPoint.getSignature() instanceof FieldSignature) {
FieldSignature fs = (FieldSignature) thisJoinPoint.getSignature();
Object target = thisJoinPoint.getTarget();
Field field = fs.getField();
field.setAccessible(true);
Object currentValue = field.get(target);
if (currentValue == null && !_$injectedObjects.contains(target)) {
_$injectedObjects.add(target);
String persistenceUnit = annotation.unitName();
EntityManagerFactory entityManagerFactory = UnmanagedEntityManagerFactory.getEntityManagerFactory(persistenceUnit);
field.set(target, entityManagerFactory);
return entityManagerFactory;
} else {
return thisJoinPoint.proceed();
}
} else {
throw new IllegalStateException("aspect advise handle only field, please check your pointcut");
}
}
// track field with ProceedingJoinPoint and annotation information with @annotation(annotation)
@Around("trackEntityManagerField(jp, esjp) && @annotation(annotation)")
public Object trackEntityManagerToInject(final JoinPoint jp, final JoinPoint.EnclosingStaticPart esjp, final ProceedingJoinPoint thisJoinPoint,
final PersistenceContext annotation) throws Throwable {
if (thisJoinPoint.getSignature() instanceof FieldSignature) {
FieldSignature fs = (FieldSignature) thisJoinPoint.getSignature();
Object target = thisJoinPoint.getTarget();
Field field = fs.getField();
field.setAccessible(true);
Object currentValue = field.get(target);
if (currentValue == null && !_$injectedObjects.contains(target)) {
_$injectedObjects.add(target);
String persistenceContext = annotation.unitName();
EntityManager entityManager = UnmanagedEntityManagerFactory.currentEntityManager(persistenceContext);
field.set(target, entityManager);
return entityManager;
} else {
return thisJoinPoint.proceed();
}
} else {
throw new IllegalStateException("aspect advise handle only field, please check your pointcut");
}
}
}