/*
* JBoss, Home of Professional Open Source.
* Copyright 2006, Red Hat Middleware LLC, and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.aspects.tx;
import org.jboss.aop.joinpoint.FieldReadInvocation;
import org.jboss.aop.joinpoint.FieldWriteInvocation;
import org.jboss.tm.TransactionLocal;
/**
* This aspect should be scoped PER_JOINPOINT
* It allows a field to have the value of itself pertain
* to the current transaction.
*
* The fields transactional and non-transactional value is always separate
* At tx commit, the transactional value the field had is wiped away.
* At tx commit, the transactional value does not correspond to the non-transactional value
*
* If you are within a transaction and you get the value of the field before setting it
* then the initial transational value will be set to the current non-transactional value
*
* @author <a href="mailto:bill@jboss.org">Bill Burke</a>
* @version $Revision: 57186 $
*/
public class TransactionLocalAspect
{
private TransactionLocal txLocal = new TransactionLocal();
public Object access(FieldReadInvocation invocation) throws Throwable
{
// Return non-Tx value
if (txLocal.getTransaction() == null) return invocation.invokeNext();
// just in case we have a primitive, we can't return null so set txLocal to be the current nonTx value
if (txLocal.get() == null)
{
txLocal.set(invocation.invokeNext());
}
return txLocal.get();
}
public Object access(FieldWriteInvocation invocation) throws Throwable
{
// Return non-Tx value
if (txLocal.getTransaction() == null) return invocation.invokeNext();
txLocal.set(invocation.getValue());
return null;
}
}
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