/*
* This file is part of FFMQ.
*
* FFMQ 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 of the License, or
* (at your option) any later version.
*
* FFMQ 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 FFMQ; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package net.timewalker.ffmq3.common.session;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageListener;
import javax.jms.Session;
import net.timewalker.ffmq3.FFMQException;
import net.timewalker.ffmq3.common.message.AbstractMessage;
import net.timewalker.ffmq3.storage.message.MessageSerializationLevel;
import net.timewalker.ffmq3.utils.ErrorTools;
import net.timewalker.ffmq3.utils.id.IntegerID;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* <p>Base implementation for a {@link MessageConsumer}</p>
*/
public abstract class AbstractMessageConsumer extends AbstractMessageHandler implements MessageConsumer
{
private static final Log log = LogFactory.getLog(AbstractMessageConsumer.class);
// Attributes
protected String messageSelector;
protected boolean noLocal;
protected MessageListener messageListener;
protected boolean autoAcknowledge;
/**
* Constructor
*/
public AbstractMessageConsumer( AbstractSession session,
Destination destination,
String messageSelector,
boolean noLocal,
IntegerID consumerId ) throws JMSException
{
super(session,destination,consumerId);
this.messageSelector = messageSelector;
this.noLocal = noLocal;
this.autoAcknowledge =
(session.getAcknowledgeMode() == Session.AUTO_ACKNOWLEDGE ||
session.getAcknowledgeMode() == Session.DUPS_OK_ACKNOWLEDGE);
if (destination == null)
throw new FFMQException("Message consumer destination cannot be null","INVALID_DESTINATION");
}
protected abstract boolean shouldLogListenersFailures();
/* (non-Javadoc)
* @see javax.jms.MessageProducer#close()
*/
public final void close() throws JMSException
{
synchronized (externalAccessLock)
{
if (closed)
return;
closed = true;
onConsumerClose();
}
onConsumerClosed();
}
/**
* @throws JMSException
*/
protected void onConsumerClose()
{
session.unregisterConsumer(this);
}
/**
* @throws JMSException
*/
protected void onConsumerClosed()
{
// Nothing
}
/* (non-Javadoc)
* @see javax.jms.MessageConsumer#getMessageSelector()
*/
public final String getMessageSelector()
{
return messageSelector;
}
/* (non-Javadoc)
* @see javax.jms.MessageConsumer#getMessageListener()
*/
public final MessageListener getMessageListener()
{
return messageListener;
}
/* (non-Javadoc)
* @see javax.jms.MessageConsumer#setMessageListener(javax.jms.MessageListener)
*/
public void setMessageListener(MessageListener messageListener) throws JMSException
{
synchronized (externalAccessLock)
{
checkNotClosed();
this.messageListener = messageListener;
}
}
/* (non-Javadoc)
* @see javax.jms.MessageConsumer#receive()
*/
public final Message receive() throws JMSException
{
return receive(-1);
}
/* (non-Javadoc)
* @see javax.jms.MessageConsumer#receiveNoWait()
*/
public final Message receiveNoWait() throws JMSException
{
return receive(0);
}
/*
* (non-Javadoc)
* @see javax.jms.MessageConsumer#receive(long)
*/
public final Message receive(long timeout) throws JMSException
{
if (messageListener != null)
throw new FFMQException("Cannot receive messages while a listener is active","INVALID_OPERATION");
AbstractMessage message = receiveFromDestination(timeout,true);
if (message != null)
{
message.ensureDeserializationLevel(MessageSerializationLevel.FULL);
message.setSession(session);
// Auto acknowledge message
if (autoAcknowledge)
session.acknowledge();
}
return message;
}
/**
* Receive a message from a destination
*/
protected abstract AbstractMessage receiveFromDestination( long timeout , boolean duplicateRequired ) throws JMSException;
/**
* Wake up the consumer message listener
*/
protected final void wakeUpMessageListener()
{
try
{
while (true)
{
synchronized (session.deliveryLock) // [JMS spec]
{
AbstractMessage message = receiveFromDestination(0,true);
if (message == null)
break;
// Make sure the message's session is set
message.setSession(session);
// Call the message listener
boolean listenerFailed = false;
try
{
messageListener.onMessage(message);
}
catch (Throwable e)
{
listenerFailed = true;
if (shouldLogListenersFailures())
log.error("Message listener failed",e);
}
// Auto acknowledge message
if (autoAcknowledge)
{
if (listenerFailed)
session.recover();
else
session.acknowledge();
}
}
}
}
catch (JMSException e)
{
ErrorTools.log(e, log);
}
}
/**
* Notify the consumer of the immediate availability of a new message
*/
public abstract void messageAvailable() throws JMSException;
}