/*
* JBoss, Home of Professional Open Source
* Copyright 2005, JBoss Inc., and individual contributors as indicated
* by the @authors tag. See the copyright.txt 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.jms.client.delegate;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.Serializable;
import javax.jms.JMSException;
import org.jboss.jms.client.state.HierarchicalState;
import org.jboss.jms.util.MessagingJMSException;
import org.jboss.jms.util.MessagingNetworkFailureException;
import org.jboss.jms.wireformat.RequestSupport;
import org.jboss.jms.wireformat.ResponseSupport;
import org.jboss.logging.Logger;
import org.jboss.messaging.util.Streamable;
import org.jboss.remoting.CannotConnectException;
import org.jboss.remoting.Client;
import org.jboss.remoting.ConnectionFailedException;
/**
* Base class for all client-side delegate classes.
*
* Client-side delegate classes provide an empty implementation of the appropriate delegate
* interface. The classes are advised using JBoss AOP to provide the client side advice stack.
* The methods in the delegate class will never actually be invoked since they will either be
* handled in the advice stack or invoked on the server before reaching the delegate.
*
* The delegates are created on the server and serialized back to the client. When they arrive on
* the client, the init() method is called which causes the advices to be bound to the advised
* class.
*
* @author <a href="mailto:tim.fox@jboss.com">Tim Fox</a>
* @author <a href="mailto:ovidiu@jboss.org">Ovidiu Feodorov</a>
*
* @version <tt>$Revision: 2485 $</tt>
*
* $Id: DelegateSupport.java 2485 2007-02-28 02:30:33Z ovidiu.feodorov@jboss.com $
*/
public abstract class DelegateSupport implements Streamable, Serializable
{
// Constants ------------------------------------------------------------------------------------
private static final Logger log = Logger.getLogger(DelegateSupport.class);
private static boolean trace = log.isTraceEnabled();
// Attributes -----------------------------------------------------------------------------------
// This is set on the server.
protected int id;
// This is set on the client.
// The reason we don't use the meta-data to store the state for the delegate is to avoid the
// extra HashMap lookup that would entail. This can be significant since the state could be
// queried for many aspects in an a single invocation.
protected transient HierarchicalState state;
protected transient byte version;
protected transient Client client;
// Static ---------------------------------------------------------------------------------------
// Constructors ---------------------------------------------------------------------------------
public DelegateSupport(int id)
{
this.id = id;
this.state = null;
}
public DelegateSupport()
{
this(Integer.MIN_VALUE);
}
// Interceptor implementation -------------------------------------------------------------------
public String getName()
{
// Neede a meaninful name to change the aop stack programatically (HA uses that)
return this.getClass().getName();
}
// Streamable implementation --------------------------------------------------------------------
public void read(DataInputStream in) throws Exception
{
id = in.readInt();
}
public void write(DataOutputStream out) throws Exception
{
out.writeInt(id);
}
// Public ---------------------------------------------------------------------------------------
public HierarchicalState getState()
{
return state;
}
public void setState(HierarchicalState state)
{
this.state = state;
this.version = state.getVersionToUse().getProviderIncrementingVersion();
}
public int getID()
{
return id;
}
/**
* During HA events, delegates corresponding to new enpoints on the new server are created and
* the state of those delegates has to be transfered to the "failed" delegates. For example, a
* "failed" connection delegate will have to assume the ID of the new connection endpoint, the
* new RemotingConnection instance, etc.
*/
public void synchronizeWith(DelegateSupport newDelegate) throws Exception
{
id = newDelegate.getID();
}
// Package protected ----------------------------------------------------------------------------
// Protected ------------------------------------------------------------------------------------
protected Object doInvoke(Client client, RequestSupport req) throws JMSException
{
return doInvoke(client, req, false);
}
protected Object doInvokeOneway(Client client, RequestSupport req) throws JMSException
{
return doInvoke(client, req, true);
}
// Private --------------------------------------------------------------------------------------
private Object doInvoke(Client client, RequestSupport req, boolean oneWay) throws JMSException
{
try
{
Object resp = null;
if (oneWay)
{
if (trace) { log.trace(this + " invoking " + req + " asynchronously on server using " + client); }
client.invokeOneway(req);
if (trace) { log.trace(this + " asynchronously invoked " + req + " on server, no response expected"); }
}
else
{
if (trace) { log.trace(this + " invoking " + req + " synchronously on server using " + client); }
resp = client.invoke(req);
if (trace) { log.trace(this + " got server response for " + req + ": " + resp); }
}
Object res = null;
if (resp instanceof ResponseSupport)
{
res = ((ResponseSupport)resp).getResponse();
}
return res;
}
catch (Throwable t)
{
throw handleThrowable(t);
}
}
public JMSException handleThrowable(Throwable t)
{
// ConnectionFailedException could happen during ConnectionFactory.createConnection.
// IOException could happen during an interrupted exception.
// CannotConnectionException could happen during a communication error between a connected
// remoting client and the server (what means any new invocation).
if (t instanceof JMSException)
{
return (JMSException)t;
}
else if ((t instanceof CannotConnectException) ||
(t instanceof IOException) ||
(t instanceof ConnectionFailedException))
{
log.warn("Captured Exception:" + t, t);
return new MessagingNetworkFailureException((Exception)t);
}
else
{
log.error("Failed", t);
return new MessagingJMSException("Failed to invoke", t);
}
}
public Client getClient()
{
return client;
}
// Inner classes --------------------------------------------------------------------------------
}