ipcjmsmessagelistener.java

实现了Jms的服务器源码,支持多种适配器,DB,FTP,支持多种数据库

/**
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 * ("Software"), with or without modification, are permitted provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright
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 *    copy of this document.
 *
 * 2. Redistributions in binary form must reproduce the
 *    above copyright notice, this list of conditions and the
 *    following disclaimer in the documentation and/or other
 *    materials provided with the distribution.
 *
 * 3. The name "Exolab" must not be used to endorse or promote
 *    products derived from this Software without prior written
 *    permission of Exoffice Technologies.  For written permission,
 *    please contact [e-mail].
 *
 * 4. Products derived from this Software may not be called "Exolab"
 *    nor may "Exolab" appear in their names without prior written
 *    permission of Exoffice Technologies. Exolab is a registered
 *    trademark of Exoffice Technologies.
 *
 * 5. Due credit should be given to the Exolab Project
 *    (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
 * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Copyright 2000-2003 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: IpcJmsMessageListener.java,v 1.8 2003/08/07 13:32:54 tanderson Exp $
 *
 * Date         Author  Changes
 * $Date	    jimm    Created
 */

package org.exolab.jms.client.mipc;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.Vector;

import javax.jms.Message;

import org.exolab.core.mipc.MultiplexConnectionIfc;
import org.exolab.core.mipc.ObjectChannel;
import org.exolab.jms.client.JmsMessageListener;


/**
 * All callbacks for ipc message delivery are registered with the single
 * instance of this object, by their session id's.
 * Arriving messages are also contain a session id, which is used to look up
 * the callback this message is destined for.
 *
 * @version     $Revision: 1.8 $ $Date: 2003/08/07 13:32:54 $
 * @author      <a href="mailto:[e-mail]">Jim Mourikis</a>
 * @see         org.exolab.jms.client.mipc.IpcJmsSessionStub
 */
class IpcJmsMessageListener implements Runnable {

    /**
     * The set of MessageListener instances, keyed on session id
     */
    private Map _listeners = Collections.synchronizedMap(new HashMap(10));

    /**
     * The channel to receive messages on
     */
    private ObjectChannel _channel;

    /**
     * Thread for receiving and dispatching messages
     */
    private Thread _thread;

    /**
     * If <code>true</code> indicates that the thread should stop
     */
    private boolean _interrupted = false;

    /**
     * Synchronization helper
     */
    private final Object _lock = new Object();


    /**
     * Construct a new <code>IpcJmsMessageListener</code>
     *
     * @param connection the connection to the server
     */
    public IpcJmsMessageListener(MultiplexConnectionIfc connection) {
        if (connection == null) {
            throw new IllegalArgumentException(
                "Argument 'connection' is null");
        }
        synchronized (connection) {
            _channel = new ObjectChannel("message", connection);
        }
    }

    /**
     * Set a new callback for a session.
     *
     * @param sessionId the unique session id
     * @param listener the listener callback to call when new messages arrive.
     */
    public void setListener(String sessionId, JmsMessageListener listener) {
        _listeners.put(sessionId, listener);
    }

    /**
     * A session has been closed. Remove its callback.
     *
     * @param sessionId the unique session id
     */
    public void closeSession(String sessionId) {
        _listeners.remove(sessionId);
    }

    /**
     * Close all session callbacks
     */
    public void closeAllSessions() {
        _listeners.clear();
    }

    /**
     * This method is called back by the server whenever it has a message for
     * this session.
     *
     * @param sessionId the session this message is for
     * @param message the message being sent to this session.
     */
    public void onMessage(String sessionId, Message message) {
        JmsMessageListener listener =
            (JmsMessageListener) _listeners.get(sessionId);

        if (listener != null) {
            listener.onMessage(message);
        }
    }

    /**
     * This method is called back by the server whenever it has one or more
     * messages for this session.
     *
     * @param sessionId the session this message is for.
     * @param messages the messages
     */
    public void onMessages(String sessionId, Vector messages) {
        JmsMessageListener listener =
            (JmsMessageListener) _listeners.get(sessionId);
        if (listener != null) {
            listener.onMessages(messages);
        }
    }

    /**
     * This method is called to notify the client that a message is available.
     *
     * @param sessionId the session this message is for.
     * @param clientId the client id to notify
     */
    public void onMessageAvailable(String sessionId, long clientId) {
        JmsMessageListener listener =
            (JmsMessageListener) _listeners.get(sessionId);
        if (listener != null) {
            listener.onMessageAvailable(clientId);
        }
    }

    /**
     * Start a thread to receive messages
     */
    public void start() {
        synchronized (_lock) {
            if (_thread == null) {
                _interrupted = false;
                _thread = new Thread(this);
                _thread.start();
            }
        }
    }

    /**
     * Stop the message receiver thread
     */
    public void stop() {
        closeAllSessions();
        synchronized (_lock) {
            if (_thread != null) {
                _interrupted = true;
                _thread.interrupt();
            }
        }
    }

    /**
     * This is called when we start up an inbound message pump in a
     * a separate thread. The method sits in a loop and consumes messages
     * coming from the server.
     */
    public void run() {
        try {
            while (!_interrupted) {
                Vector v = (Vector) _channel.receive();

                String sessionId = (String) v.get(0);
                if (v.get(1) instanceof Message) {
                    onMessage(sessionId, (Message) v.get(1));
                } else if (v.get(1) instanceof Vector) {
                    onMessages(sessionId, (Vector) v.get(1));
                } else if (v.get(1) instanceof Long) {
                    onMessageAvailable(sessionId,
                        ((Long) v.get(1)).longValue());
                }
                _channel.send(new Vector());
            }
        } catch (Exception ignore) {
        } finally {
            try {
                _channel.close();
            } catch (Exception ignore) {
            }

            synchronized (_lock) {
                _thread = null;
            }
        }
    }

} //-- IpcJmsMessageListener