httpjmsjndiservlet.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 2001-2003 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: HttpJmsJndiServlet.java,v 1.8 2003/08/17 01:32:23 tanderson Exp $
 *
 * Date				Author  Changes
 * Fri 21 Sep 2001	mourikis    Created
 *
 */

package org.exolab.jms.jndi.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.Client;
import org.exolab.core.mipc.TcpConstants;
import org.exolab.jms.jndi.JndiConstants;


/**
 * Servlet for handling OpenJMS JNDI requests.
 *
 * @version     $Revision: 1.8 $ $Date: 2003/08/17 01:32:23 $
 * @author      <a href="mailto:[e-mail]">Jim Mourikis</a>
 */
public class HttpJmsJndiServlet extends HttpServlet {

    // This is a reference to the server connection.
    private static Client connection_ = null;

    // The server host address
    private static String serverAddress_ = TcpConstants.LOCAL_HOST;

    // The port number the server is listening to
    private static int port_ = TcpConstants.DEFAULT_PORT + 5;

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


    // Is there a valid connection to OpenJMS server.
    private static boolean connected_ = false;

    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) {
                serverAddress_ = host;
            }
            if (port != null) {
                port_ = Integer.parseInt(port);
            }
        }
        connect();
    }


    /**Process the HTTP Post request*/
    public void doPost(HttpServletRequest request,
                       HttpServletResponse response)
        throws ServletException, IOException {

        // handle request
        ObjectInputStream inputStream = new ObjectInputStream(
            new BufferedInputStream(request.getInputStream()));

        // prepare response
        ObjectOutputStream oos = new ObjectOutputStream
            (new BufferedOutputStream(response.getOutputStream()));
        response.setContentType(CONTENT_TYPE);
        try {
            if (!connected_) {
                connect();
            }
            Object o = null;
            o = inputStream.readObject();
            if (o != null && (o instanceof Vector)) {
                synchronized (connection_) {
                    try {
                        connection_.send((Vector) o);
                    } catch (Exception err) {
                        // might have disconnected. Try and re-connect.
                        // if connection fails again, then exception is just
                        // re-thrown.
                        connected_ = false;
                        connect();
                        connection_.send((Vector) o);
                    }

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


    /**
     * Connect to the openjms server.
     *
     */
    protected void connect() throws ServletException {

        try {
            connection_ = new Client(serverAddress_, port_);
        } catch (Exception err) {
            String message =
                "HttpJmsJndiServlet: Failed to connect\nReason: " +
                err.getMessage();
            System.err.println(message);
            throw new ServletException(message);
        }

        System.out.println("JMS JNDI Servlet connected.");
        connected_ = true;
    }

    /**Clean up resources*/
    public void destroy() {

        if (connection_ != null) {
            try {
                connection_.close();
            } catch (Exception ignored) {
            } finally {
                connection_ = null;
                connected_ = false;
            }
        }
    }

    public String getServletInfo() {
        return "Not implemented yet";
    }

} // End HttpJmsJndiServlet