/*
* 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.remote.session;
import java.util.NoSuchElementException;
import javax.jms.JMSException;
import javax.jms.Message;
import net.timewalker.ffmq3.common.message.AbstractMessage;
import net.timewalker.ffmq3.common.session.AbstractQueueBrowserEnumeration;
import net.timewalker.ffmq3.storage.message.MessageSerializationLevel;
import net.timewalker.ffmq3.transport.PacketTransportEndpoint;
import net.timewalker.ffmq3.transport.packet.query.CloseBrowserEnumerationQuery;
import net.timewalker.ffmq3.transport.packet.query.QueueBrowserFetchElementQuery;
import net.timewalker.ffmq3.transport.packet.query.QueueBrowserGetEnumerationQuery;
import net.timewalker.ffmq3.transport.packet.response.QueueBrowserFetchElementResponse;
import net.timewalker.ffmq3.transport.packet.response.QueueBrowserGetEnumerationResponse;
import net.timewalker.ffmq3.utils.ErrorTools;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* RemoteQueueBrowserEnumeration
*/
public final class RemoteQueueBrowserEnumeration extends AbstractQueueBrowserEnumeration
{
private static final Log log = LogFactory.getLog(RemoteQueueBrowserEnumeration.class);
// Parent connection
private PacketTransportEndpoint transportEndpoint;
// Parent session
private RemoteSession session;
// Attributes
private AbstractMessage nextMessage;
private boolean endOfQueueReached;
/**
* Constructor
*/
public RemoteQueueBrowserEnumeration( RemoteSession session , RemoteQueueBrowser browser )
{
super(browser,null);
this.transportEndpoint = session.getTransportEndpoint();
this.session = session;
}
/**
* Initialize the remote endpoint for this session
*/
protected void remoteInit() throws JMSException
{
QueueBrowserGetEnumerationQuery query = new QueueBrowserGetEnumerationQuery();
query.setSessionId(session.getId());
query.setBrowserId(browser.getId());
QueueBrowserGetEnumerationResponse response = (QueueBrowserGetEnumerationResponse)transportEndpoint.blockingRequest(query);
this.id = response.getEnumId();
log.debug("Remote queue browser enumeration ID is "+id);
}
private AbstractMessage fetchNext() throws JMSException
{
if (nextMessage != null) // Already fetched ?
return nextMessage;
// Lookup next candidate
QueueBrowserFetchElementQuery query = new QueueBrowserFetchElementQuery();
query.setSessionId(session.getId());
query.setBrowserId(browser.getId());
query.setEnumId(id);
QueueBrowserFetchElementResponse response = (QueueBrowserFetchElementResponse)transportEndpoint.blockingRequest(query);
nextMessage = response.getMessage();
if (nextMessage == null)
{
endOfQueueReached = true;
close(); // Auto-close enumeration at end of queue
}
return nextMessage;
}
/* (non-Javadoc)
* @see java.util.Enumeration#hasMoreElements()
*/
public boolean hasMoreElements()
{
if (endOfQueueReached)
return false;
try
{
checkNotClosed();
Message msg = fetchNext();
return msg != null;
}
catch (JMSException e)
{
throw new IllegalStateException(e.toString());
}
}
/* (non-Javadoc)
* @see java.util.Enumeration#nextElement()
*/
public Object nextElement()
{
if (endOfQueueReached)
throw new NoSuchElementException();
try
{
checkNotClosed();
AbstractMessage msg = fetchNext();
if (msg != null)
{
nextMessage = null; // Consume fetched message
// Make sure the message is fully deserialized and marked as read-only
msg.ensureDeserializationLevel(MessageSerializationLevel.FULL);
msg.markAsReadOnly();
return msg;
}
throw new NoSuchElementException();
}
catch (NoSuchElementException e)
{
throw e;
}
catch (JMSException e)
{
throw new IllegalStateException(e.toString());
}
}
/* (non-Javadoc)
* @see net.timewalker.ffmq3.common.session.AbstractQueueBrowserEnumeration#onQueueBrowserEnumerationClose()
*/
protected void onQueueBrowserEnumerationClose()
{
try
{
CloseBrowserEnumerationQuery query = new CloseBrowserEnumerationQuery();
query.setSessionId(session.getId());
query.setBrowserId(browser.getId());
query.setEnumId(id);
transportEndpoint.blockingRequest(query);
}
catch (JMSException e)
{
ErrorTools.log(e, log);
}
}
}