/*
* 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.versioned;
import org.jboss.aop.joinpoint.FieldReadInvocation;
import org.jboss.aop.joinpoint.FieldWriteInvocation;
import org.jboss.aop.joinpoint.MethodInvocation;
import org.jboss.logging.Logger;
import javax.transaction.Transaction;
import javax.transaction.TransactionManager;
/**
* This interceptor handles chooses an object to invoke
* on based on the transaction
*
* @author <a href="mailto:bill@jboss.org">Bill Burke</a>
* @version $Revision: 57186 $
*/
public class VersionedObjectInterceptor implements org.jboss.aop.advice.Interceptor
{
/**
* Logging instance
*/
protected Logger log = Logger.getLogger(this.getClass());
private TransactionManager tm;
public VersionedObjectInterceptor(TransactionManager tm)
{
this.tm = tm;
}
public String getName() { return "VersionedObjectInterceptor"; }
/**
*
*/
public Object invoke(org.jboss.aop.joinpoint.Invocation invocation) throws Throwable
{
Transaction tx = tm.getTransaction();
VersionedObject manager = (VersionedObject)invocation.getMetaData(Versioned.VERSIONED, Versioned.VERSIONED_OBJECT);
Object version = manager.getVersion(tx);
if (version != null)
{
invocation.setTargetObject(version);
return invocation.invokeNext();
}
boolean isReadonly = false;
if (invocation instanceof MethodInvocation)
{
String readonly = (String)invocation.getMetaData(Versioned.VERSIONED, Versioned.READONLY);
if (readonly != null)
{
isReadonly = Boolean.getBoolean(readonly.toLowerCase());
}
}
else if (invocation instanceof FieldReadInvocation)
{
isReadonly = true;
}
else if (invocation instanceof FieldWriteInvocation)
{
isReadonly = false;
}
if (isReadonly) return invocation.invokeNext();
// Ok, we're in a tx, we're not readonly, there is no previous version, so create another
version = manager.createVersion(tx);
invocation.setTargetObject(version);
return invocation.invokeNext();
}
}
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