Jetty example source code file (ContinuationClient.java)

This example Jetty source code file (ContinuationClient.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Jetty tags/keywords

clientimpl, clientimpl, continuation, continuation, continuationbayeux, continuationbayeux, continuationclient, continuationclient, string, t

The Jetty ContinuationClient.java source code

// ========================================================================
// Copyright 2006 Mort Bay Consulting Pty. Ltd.
// ------------------------------------------------------------------------
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at 
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// ========================================================================

package org.mortbay.cometd.continuation;

import org.mortbay.cometd.ClientImpl;
import org.mortbay.thread.Timeout;
import org.mortbay.util.ajax.Continuation;

/* ------------------------------------------------------------ */
/**
 * Extension of {@link ClientImpl} that uses {@link Continuation}s to
 * resume clients waiting for messages. Continuation clients are used for
 * remote clients and have removed if they are not accessed within
 * an idle timeout (@link {@link ContinuationBayeux#_clientTimer}).
 * 
 * @author gregw
 *
 */
public class ContinuationClient extends ClientImpl
{
    private long _accessed;
    public transient Timeout.Task _timeout; 
    private ContinuationBayeux _bayeux;
    private transient Continuation _continuation;

    /* ------------------------------------------------------------ */
    protected ContinuationClient(ContinuationBayeux bayeux)
    {
        super(bayeux);
        _bayeux=bayeux;

        if (!isLocal())
        {
            _timeout=new Timeout.Task()
            {
                public void expire()
                {
                    remove(true);
                }
                public String toString()
                {
                    return "T-"+ContinuationClient.this.toString();
                }
            };
            _bayeux.startTimeout(_timeout,getTimeout());
        }
    }


    /* ------------------------------------------------------------ */
    public void setContinuation(Continuation continuation)
    {
        Timeout.Task task=null;
        
        if (continuation==null)
        {
            synchronized (this)
            {
                if (_continuation!=null)
                {
                    if(_continuation.isPending())
                        _continuation.resume(); 
                }
                _continuation=null;
                task=_timeout;
            }

            if (task!=null)
                _bayeux.startTimeout(task,getTimeout());
        }
        else
        {
            synchronized (this)
            {
                if (_continuation!=null)
                {
                    if(_continuation.isPending())
                        _continuation.resume(); 
                }
                _continuation=continuation;
                task=_timeout;
            }

            if (task!=null)
                _bayeux.cancelTimeout(task);
        }
    }
    
    /* ------------------------------------------------------------ */
    public Continuation getContinuation()
    {
        return _continuation;
    }

    /* ------------------------------------------------------------ */
    public void resume()
    {
        Timeout.Task task=null;
        synchronized (this)
        {
            if (_continuation!=null)
            {
                _continuation.resume();
                task=_timeout;
            }
            _continuation=null;
        }
        
        if (task!=null)
            _bayeux.startTimeout(task,getTimeout());
    }

    /* ------------------------------------------------------------ */
    public boolean isLocal()
    {
        return false;
    }

    /* ------------------------------------------------------------ */
    public void access()
    {
        Timeout.Task task=null;
        synchronized(this)
        {
            // distribute access time in cluster
            _accessed=_bayeux.getNow();
            if (_timeout!=null && _timeout.isScheduled())
                task=_timeout;
        }
        
        if (task!=null)
            _bayeux.startTimeout(task,getTimeout());
    }


    /* ------------------------------------------------------------ */
    public synchronized long lastAccessed()
    {
        return _accessed;
    }
    
    /* ------------------------------------------------------------ */
    /* (non-Javadoc)
     * @see org.mortbay.cometd.ClientImpl#remove(boolean)
     */
    public void remove(boolean wasTimeout) 
    {
        Timeout.Task task=null;
        synchronized(this)
        {
            task=_timeout;
            _timeout=null;
            super.remove(wasTimeout);
        }
        
        if (task!=null)
            _bayeux.cancelTimeout(task);
        
    }

}