httpjmsserverservlet.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

/**
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright
 *    statements and notices.  Redistributions must also contain a
 *    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 2001-2002 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: HttpJmsServerServlet.java,v 1.7 2003/08/07 13:33:09 tanderson Exp $
 *
 * Date				Author  Changes
 * Fri 21 Sep 2001	mourikis    Created
 *
 */
package org.exolab.jms.server.http.servlet;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.Vector;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.exolab.core.ipc.IpcIfc;
import org.exolab.core.mipc.DisconnectionEventListener;
import org.exolab.core.mipc.MultiplexConnection;
import org.exolab.core.mipc.MultiplexConnectionIfc;
import org.exolab.core.mipc.ObjectChannel;
import org.exolab.core.mipc.TcpConstants;
import org.exolab.jms.jndi.JndiConstants;


/**
 * Servlet for handling OpenJMS server requests and message publishing.
 *
 * @version     $Revision: 1.7 $ $Date: 2003/08/07 13:33:09 $
 * @author      <a href="mailto:[e-mail]">Jim Mourikis</a>
 */
public class HttpJmsServerServlet extends HttpServlet
    implements DisconnectionEventListener {

    // This is a reference to the server connection.
    private static MultiplexConnectionIfc _mc = null;

    private static IpcIfc _connection = null;

    /**
     * The server host name
     */
    private static String _host = TcpConstants.LOCAL_HOST;

    /**
     * The port number the server is listening to
     */
    private static int _port = TcpConstants.DEFAULT_PORT;

    /**
     * The content type of the data.
     */
    private static final String CONTENT_TYPE = "text/html";


    /**
     * Called by the servlet container to indicate to a servlet that the
     * servlet is being placed into service.
     */
    public void init(ServletConfig config) throws ServletException {
        super.init(config);

        if (config != null) {
            String host = config.getInitParameter(JndiConstants.HOST_PROPERTY);
            String port = config.getInitParameter(
                JndiConstants.PORT_NUMBER_PROPERTY);
            if (host != null) {
                _host = host;
            }
            if (port != null) {
                _port = Integer.parseInt(port);
            }
        }
        connect();

        log("OpenJMS server servlet ready");
    }

    /**
     * Handle HTTP POST requests
     *
     * @param request contains the request the client has made of the servlet
     * @param response contains the response the servlet sends to the client
     * @throws IOException if an I/O error is encountered
     */
    public void doPost(HttpServletRequest request,
                       HttpServletResponse response)
        throws IOException {

        ObjectInputStream input = new ObjectInputStream(
            new BufferedInputStream(request.getInputStream()));
        ObjectOutputStream output = new ObjectOutputStream(
            new BufferedOutputStream(response.getOutputStream()));
        response.setContentType(CONTENT_TYPE);

        try {
            if (_mc == null) {
                connect();
            }
            Object object = input.readObject();
            if (object instanceof Vector) {
                synchronized (_connection) {
                    Vector message = (Vector) object;
                    _connection.send(message);

                    String type = request.getHeader("jms-response");
                    if (type != null && type.equals("yes")) {
                        message = (Vector) _connection.receive();
                        output.writeObject(message);
                    }
                }
                // send response
                response.setStatus(HttpServletResponse.SC_OK);
            } else {
                response.setStatus
                    (HttpServletResponse.SC_UNSUPPORTED_MEDIA_TYPE);
                output.writeObject("Object is NULL, or UNEXPECTED type");
            }
        } catch (Exception exception) {
            response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            output.writeObject(exception.getMessage());
        } finally {
            output.flush();
        }
    }


    /**Clean up resources*/
    public void destroy() {
        disconnected(null);
    }

    // implementation of DisconnectionEventListener.disconnected
    public void disconnected(MultiplexConnectionIfc connection) {
        if (_mc != null) {
            try {
                _mc.finish();
                _connection.close();
            } catch (Exception ignore) {
                // just swallow
            } finally {
                _mc = null;
                _connection = null;
            }
        }
    }

    /**
     * Connect to the OpenJMS server.
     */
    protected void connect() throws ServletException {
        try {
            _mc = new MultiplexConnection(_host, _port);
        } catch (Exception exception) {
            String message = "Failed to connect using host=" + _host +
                " and port=" + _port + " " + exception.getMessage();
            log(message);
            throw new ServletException(message);
        }

        _mc.setDisconnectionEventListener(this);
        ((Thread) _mc).start();

        _connection = new ObjectChannel("server", _mc);
    }

} //-- HttpJmsServerServlet