httpjmsserverstub.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 2001,2003 (C) Exoffice Technologies Inc. All Rights Reserved.
 *
 * $Id: HttpJmsServerStub.java,v 1.8 2003/08/07 13:32:51 tanderson Exp $
 *
 * Date             Author      Changes
 * 12 Oct 2001	    mourikis    Created
 */


package org.exolab.jms.client.http;

import java.io.IOException;
import java.util.Hashtable;
import java.util.Vector;

import javax.jms.ExceptionListener;
import javax.jms.JMSException;

import org.exolab.core.http.HttpClient;
import org.exolab.jms.client.JmsConnectionStubIfc;
import org.exolab.jms.client.JmsServerStubIfc;


/**
 * This class is repsonsible for opening an http connection to the server
 * and creating HttpJmsConnections.
 *
 * @version     $Revision: 1.8 $ $Date: 2003/08/07 13:32:51 $
 * @author      <a href="mailto:[e-mail]">Jim Mourikis</a>
 * @see         org.exolab.core.http.HttpClient
 */
public class HttpJmsServerStub implements JmsServerStubIfc {

    /**
     * The server URL
     */
    private String _url;

    /**
     * The connection label. @todo - HttpClient doesn't appear to use this
     */
    private String _label = "HttpJmsServerStub";

    /**
     * The exception listener is used to communicate server connection
     * problems
     */
    private ExceptionListener _listener = null;


    /**
     * Default constructor
     */
    public HttpJmsServerStub() {
    }

    /**
     * The constructor has a collection of environment variables
     * which it uses to construct a connection to the remote
     * server
     *
     * @param env the connection properties
     * @throws JMSException if required connection properties aren't specified
     */
    public HttpJmsServerStub(Hashtable env) throws JMSException {
        _url = (String) env.get(HttpJmsConstants.HTTP_SERVER_URL);
        if (_url == null) {
            throw new JMSException("Required property not specified: " +
                HttpJmsConstants.HTTP_SERVER_URL);
        }
    }

    /**
     * Instantiate an instance of this stub with the specified URL
     *
     * @param  url  url of the server hosting the servlet.
     */
    public HttpJmsServerStub(String url) {
        _url = url;
    }

    /**
     * Create a connection to the JMS Server.
     *
     * @param clientId the identity of client
     * @param username the client username
     * @param password the client password
     * @throws JMSException if the connection cannot be created
     */
    public JmsConnectionStubIfc createConnection(
        String clientId, String username, String password)
        throws JMSException {
        JmsConnectionStubIfc stub = null;

        try {
            Vector v = pack("createConnection", clientId, username, password);
            HttpClient connection = new HttpClient(_url, _label);

            connection.send(v);
            String connectionId = (String) checkReply(connection,
                "createConnection");
            stub = new HttpJmsConnectionStub(
                connection, clientId, connectionId);
        } catch (IOException exception) {
            throw new JMSException("Failed to create connection, URL=" +
                _url + ": " + exception);
        }
        return stub;
    }

    // implementation of JmsServerStubIfc.setExceptionListener
    public void setExceptionListener(ExceptionListener listener) {
        _listener = listener;
    }

    /**
     * Set the URL
     *
     * @param URL the webserver URL
     */
    protected void setURL(String URL) {
        _url = URL;
    }

    /**
     * The the connection label
     */
    protected void setLabel(String label) {
        _label = label;
    }

    /**
     * A convenience method to check the success of operations which return
     * a true on sucess.
     *
     * @param connection the connection
     * @param method The requested server function.
     * @return the result of the call, or <code>null</code> if the call
     * didn't return a result
     * @throws JMSException for any failure.
     */
    protected Object checkReply(HttpClient connection, String method)
        throws JMSException {
        Object result = null;
        Vector v = null;
        try {
            v = (Vector) connection.receive();
        } catch (Exception err) {
            // rethrow as a JMSException
            throw new JMSException("Operation " + method + " failed: " + err);
        }

        if (v != null) {
            Boolean b = (Boolean) v.get(0);
            if (!b.booleanValue()) {
                if (v.get(1) instanceof JMSException) {
                    throw (JMSException) v.get(1);
                } else {
                    throw new JMSException("Operation " + method +
                        " failed:\n" + v.get(1));
                }
            }
            result = v.get(1);
        } else {
            throw new JMSException("Unknown connection error for " + method);
        }

        return result;
    }

    /**
     * Pack all the data that is required by the server in a vector.
     * Set the size of the vector to be exactly the right size for efficiency.
     *
     * @param method The function to activate on the server.
     * @param id The unique client id.
     * @param username
     * @param password
     * @return Vector The vector containing all the data.
     */
    protected Vector pack(String method, String id, String username,
                          String password) {
        Vector v = new Vector(5);
        v.add("org.exolab.jms.server.mipc.IpcJmsServerConnection");
        v.add(method);
        v.add(id);
        v.add(username);
        v.add(password);
        return v;
    }

} //-- HttpJmsServerStub