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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.cayenne.jpa;
import javax.persistence.EntityTransaction;
import javax.persistence.TransactionRequiredException;
import javax.transaction.Status;
import javax.transaction.Synchronization;
import javax.transaction.TransactionSynchronizationRegistry;
import org.apache.cayenne.ObjectContext;
/**
* An EntityManager that can participate in JTA transactions.
*
*/
public class JtaEntityManager extends ResourceLocalEntityManager {
protected Object currentTxKey;
public JtaEntityManager(ObjectContext context, JtaEntityManagerFactory factory) {
super(context, factory);
}
private JtaEntityManagerFactory getJtaFactory() {
return (JtaEntityManagerFactory) getFactory();
}
/**
* @throws IllegalStateException, as this entity manager is of JTA kind.
*/
public EntityTransaction getTransaction() {
throw new IllegalStateException(
"'getTransaction' is called on a JTA EntityManager");
}
/**
* Indicates to the EntityManager that a JTA transaction is active. This method should
* be called on a JTA application managed EntityManager that was created outside the
* scope of the active transaction to associate it with the current JTA transaction.
*
* @throws TransactionRequiredException if there is no transaction.
*/
@Override
public void joinTransaction() {
if (currentTxKey == null) {
TransactionSynchronizationRegistry registry = getJtaFactory()
.getTransactionRegistry();
registry.registerInterposedSynchronization(new TransactionBinding());
currentTxKey = registry.getTransactionKey();
}
}
/**
* @throws TransactionRequiredException if there is no transaction.
*/
@Override
public void persist(Object entity) {
checkTransaction();
super.persist(entity);
}
/**
* @throws TransactionRequiredException if there is no transaction.
*/
@Override
public <T> T merge(T entity) {
checkTransaction();
return super.merge(entity);
}
/**
* @throws TransactionRequiredException if there is no transaction.
*/
@Override
public void remove(Object entity) {
checkTransaction();
super.remove(entity);
}
/**
* @throws TransactionRequiredException if there is no transaction.
*/
@Override
public void refresh(Object entity) {
checkTransaction();
super.refresh(entity);
}
/**
* @throws TransactionRequiredException if there is no transaction.
*/
public void flush() {
checkTransaction();
super.flush();
};
/**
* @throws TransactionRequiredException if there is no transaction in progress.
*/
protected void checkTransaction() throws TransactionRequiredException {
if (!getJtaFactory().isActiveTransaction()) {
throw new TransactionRequiredException();
}
}
class TransactionBinding implements Synchronization {
public void afterCompletion(int status) {
if (status != Status.STATUS_COMMITTED) {
clear();
}
currentTxKey = null;
}
public void beforeCompletion() {
flush();
}
}
}