httprelayservlet.java

jxme的一些相关程序,主要是手机上程序开发以及手机和计算机通信的一些程序资料,程序编译需要Ant支持

/*
 *  $Id: HttpRelayServlet.java,v 1.24 2002/06/28 00:07:32 kuldeep Exp $ Copyright
 *  (c) 2001 Sun Microsystems, Inc. All rights reserved. Redistribution and use
 *  in source and binary forms, with or without modification, are permitted
 *  provided that the following conditions are met: 1. Redistributions of source
 *  code must retain the above copyright notice, this list of conditions and the
 *  following disclaimer. 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 end-user documentation included with the redistribution, if any, must
 *  include the following acknowledgment: "This product includes software
 *  developed by the Sun Microsystems, Inc. for Project JXTA." Alternately, this
 *  acknowledgment may appear in the software itself, if and wherever such
 *  third-party acknowledgments normally appear. 4. The names "Sun", "Sun
 *  Microsystems, Inc.", "JXTA" and "Project JXTA" must not be used to endorse
 *  or promote products derived from this software without prior written
 *  permission. For written permission, please contact Project JXTA at
 *  http://www.jxta.org. 5. Products derived from this software may not be
 *  called "JXTA", nor may "JXTA" appear in their name, without prior written
 *  permission of Sun. THIS SOFTWARE IS PROVIDED ``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 SUN MICROSYSTEMS 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.
 *  ==================================================================== This
 *  software consists of voluntary contributions made by many individuals on
 *  behalf of Project JXTA. For more information on Project JXTA, please see
 *  <http://www.jxta.org/>. This license is based on the BSD license adopted by
 *  the Apache Foundation.
 */

package net.jxta.impl.endpoint.servlethttp;

import java.io.*;

import java.util.HashMap;
import javax.servlet.*;


import javax.servlet.http.*;
import net.jxta.id.IDFactory;
import net.jxta.peer.PeerID;
import net.jxta.peergroup.PeerGroupID;
import net.jxta.document.MimeMediaType;
import net.jxta.impl.endpoint.*;
import net.jxta.impl.relay.RelayLease;
import net.jxta.impl.relay.RelayLeaseException;
import net.jxta.impl.relay.RelayServer;
import net.jxta.impl.util.BoundedQueue;
import net.jxta.endpoint.EndpointService;
import net.jxta.endpoint.Message;
import javax.servlet.SingleThreadModel;
import org.apache.log4j.Category; 
import org.apache.log4j.Priority;

/**
 *  Http Servlet implementation of the the HTTP Relay Server
 */
public class HttpRelayServlet extends HttpServlet {
    
    /**
     *  we allow clients to stay blocked before we send a "no msg" response
     *
     */
    private final static int BLOCK_WAIT_TIMEOUT = 60 * 1000;
    private static final MimeMediaType msgType = new MimeMediaType( "application/x-jxta-msg" );
    private final static Category LOG = Category.getInstance( HttpRelayServlet.class.getName() );
    
    /** The endpoint that the servlet is receiving messages for **/
    private EndpointService endpoint = null;
    
    /** Clients cannot POST more than 10MB **/
    private static final int MAX_POST_CONTENT_LEN = 10 * 1024 * 1024;
    
    /**
     *  the relay server that this http relay is using *
     */
    RelayServer relay = null;
    
    /**
     *  Stores the endpoint from the ServletContext in to the data member
     *  for easy access.
     */
    public void init( ServletConfig config )
    throws ServletException {
        super.init( config );
        
        try {
            relay = (RelayServer) getServletContext().getAttribute( "relayServer" );
            if ( relay == null ) {
                throw new ServletException("Servlet Context did not contain " +
                "'relayServer'" );
            }
            endpoint = (EndpointService) getServletContext().getAttribute("endpoint");
            if ( endpoint == null ){
                throw new ServletException( "Servlet Context did not contain "+
                "'endpoint'");
            }
            
        } catch ( ClassCastException e ) {
            throw new ServletException( "'relayServer' attribute was not of " +
            "the proper type in the Servlet " +
            "Context" );
        }
    }
    
    /**
     *  handles all relay get commands, in addition, it checks to see if the
     *  content-length of the GET request is not zero.  In that case, this
     *  method will validate the message content length and process it.
     *
     *  possible headers in the request
     *      x-jxta-command=[ obtainLease | releaseLease | poll ]
     *      x-jxta-client=[ peerId ]
     *      x-jxta-timeout=[ -1 (do not block) | 0 (block forever) | 1 to MAX_POSITIVE_LONG ]
     *
     *  possible headers in the response
     *      x-jxta-relay=[ peerId ]
     *      x-jxta-client=[ peerId ]
     *      x-jxta-lease=[ 1 to MAX_POSITIVE_LONG ]
     *
     */
    public void doGet( HttpServletRequest req, HttpServletResponse res )
    throws ServletException, IOException {
        
        String command = req.getHeader(HttpUtil.HEADER_PARAM_COMMAND);
        if (command == null) {
             //DoJa will send parameters as QueryString
             command = req.getParameter(HttpUtil.HEADER_PARAM_COMMAND);
        }

        String clientPeerId = req.getHeader(HttpUtil.HEADER_PARAM_CLIENT);
        if (clientPeerId == null) {
             // DoJa will send parameters as QueryString
             clientPeerId = req.getParameter(HttpUtil.HEADER_PARAM_CLIENT);
        }        

        if (LOG.isEnabledFor(Priority.DEBUG)) {
            LOG.debug( "GET received from " + req.getRemoteAddr() + " command = " + command );
            LOG.debug( "  clientPeerId = " + clientPeerId );
            LOG.debug( "  request length = " + req.getContentLength() );
        }

        // Check if the input stream has any incoming messages
        // passsed in the current req content
        // Read such messages and queue them for processing
        if (req.getContentLength() > 0) {
            int numberofMessages = 1;
            
            String numStr = req.getHeader("x-jxta-num-msg");
            if (numStr != null) {
                try {
                    numberofMessages = Integer.parseInt(numStr);
                } catch (NumberFormatException e) {
                    LOG.warn( "Could not parse x-jxta-num-msg header", e );
                }
            }
            
            LOG.debug( "  request numberofMessages = " + numberofMessages );
            
            int count = 0;
            BufferedInputStream in = new BufferedInputStream(req.getInputStream());
            try {
                for (count = 0; count < numberofMessages; count++) {
                    readMessage(in);
                }
            } catch (IOException e) {
                // done reading messages or queue is full
		if (LOG.isEnabledFor(Priority.DEBUG)) {
		     LOG.debug( "IOException during read ", e);
		}
		
            }
            in.close();
            
            LOG.debug( "  numberofMessages read = " + count );
            
            res.setHeader("x-jxta-num-msg", Integer.toString(count));
        }
        
        if (HttpUtil.COMMAND_VALUE_OBTAIN_LEASE.equals(command)) {
            // check if the client has a peerId
            if (clientPeerId == null) {
                // generate a peerId
                PeerID peerId = IDFactory.newPeerID(PeerGroupID.worldPeerGroupID);
                clientPeerId = peerId.getUniqueValue().toString();
            }
            
            res.setHeader(HttpUtil.HEADER_PARAM_RELAY,
            relay.getPeerID().getUniqueValue().toString());
            res.setHeader(HttpUtil.HEADER_PARAM_CLIENT, clientPeerId);
            
            // check if the client has a lease
            String leaseId = relay.getLeaseId(clientPeerId);
            RelayLease lease = null;
            if (leaseId == null) {
                lease = relay.issueNewLease(clientPeerId);
            } else {
                try {
                    lease = relay.renewLease(leaseId);
                } catch (RelayLeaseException e) {
                    if (LOG.isEnabledFor(Priority.DEBUG)) {
                        LOG.debug( "Lease not renewed; lease exception: " + e );
                    }
                }
            }
            
            if (lease != null) {
                res.setHeader(HttpUtil.HEADER_PARAM_LEASE,
                Long.toString(lease.getLeaseLength()));
            }
            
            res.setStatus(HttpServletResponse.SC_OK);
            res.setContentLength(0);
            
        } else if (HttpUtil.COMMAND_VALUE_RELEASE_LEASE.equals(command)) {
            // check if the client gave a peerId
            if (clientPeerId == null) {
                // check if the client has a lease
                String leaseId = relay.getLeaseId(clientPeerId);
                if (leaseId == null) {
                    relay.removeLease(leaseId);
                }
            }
            
            res.setStatus(HttpServletResponse.SC_OK);
            res.setContentLength(0);
            
        } else if (HttpUtil.COMMAND_VALUE_POLL.equals(command)) {
            // since getDateHeader() returns -1 if the header does not exist,
            // the default value is treated as do not block
            long timeout = -1;
            String timeoutString = req.getHeader(HttpUtil.HEADER_PARAM_TIMEOUT);
            if (timeoutString == null){
                // DoJa will send parameters as QueryString
                timeoutString = req.getParameter(HttpUtil.HEADER_PARAM_TIMEOUT);
            }
 
            try {
                timeout = Long.parseLong(timeoutString);
            } catch (NumberFormatException e) {
                LOG.warn( "Could not parse timeout header", e );
            }
            LOG.debug( "  timeout = " + timeout );
            
            // check if the client has a peerId
            if (clientPeerId == null) {
                // generate a peerId
                PeerID peerId = IDFactory.newPeerID(PeerGroupID.worldPeerGroupID);
                clientPeerId = peerId.getUniqueValue().toString();
            }
            
            res.setHeader(HttpUtil.HEADER_PARAM_RELAY,
            relay.getPeerID().getUniqueValue().toString());
            res.setHeader(HttpUtil.HEADER_PARAM_CLIENT, clientPeerId);
            
            // check if the client has a lease
            String leaseId = relay.getLeaseId(clientPeerId);
            RelayLease lease = null;
            if (leaseId == null) {
                lease = relay.issueNewLease(clientPeerId);
            } else {
                try {
                    lease = relay.renewLease(leaseId);
                } catch (RelayLeaseException e) {
                    if (LOG.isEnabledFor(Priority.DEBUG)) {
                        LOG.debug( "Lease not renewed; lease exception: " + e );
                    }
                }
            }
            
            if (lease != null) {
                res.setHeader(HttpUtil.HEADER_PARAM_LEASE,
                Long.toString(lease.getLeaseLength()));
            }
            
            BoundedQueue queue = relay.getOutboundMessageQueueByPeerId( clientPeerId );
            if ( queue != null ) {
                MessageImpl msg = null;
                
                try {
                    if (LOG.isEnabledFor(Priority.DEBUG)) {
                        LOG.debug( "trying to dequeue message for client " + clientPeerId );
                    }
                    
                    msg = (MessageImpl) queue.dequeue(timeout);
                } catch ( InterruptedException e ) {
                    // send back empty response
                    if (LOG.isEnabledFor(Priority.DEBUG)) {
                        LOG.debug( "No message dequeued; sending blank 200" );
                    }
                }
                
                // if there is a message, send it. Otherwise, respond with
                // okay with a 0 content-len
                if ( msg == null ) {
                    res.setStatus(HttpServletResponse.SC_OK);
                    res.setContentLength(0);
                    return;
                }
                
                if (LOG.isEnabledFor(Priority.DEBUG)) {
                    LOG.debug( "Relay sending message back for lease " + leaseId );
                }
                sendMessage( res, msg );
                
            } else {
                if (LOG.isEnabledFor(Priority.DEBUG)) {
                    LOG.debug( "No queue associate with lease (probably an " +
                    "invalid lease for client): " + clientPeerId );
                }
                res.sendError(HttpServletResponse.SC_BAD_REQUEST,
                "Invalid lease specified");
            }
        } else {
            res.sendError(HttpServletResponse.SC_BAD_REQUEST,
            "Invalid command specified");
        }
    }
    
    /**
     *  handles all relay commands
     *
     */
    public void doPost( HttpServletRequest req, HttpServletResponse res )
    throws ServletException, IOException {

        if (LOG.isEnabledFor(Priority.DEBUG)) {
            LOG.debug( "POST received from " + req.getRemoteAddr() );
            LOG.debug( "  request length = " + req.getContentLength() );
        }
        
        // When using Java HttpURLConnection, if getOutputStream() is called on the client,
        // the request type is set to POST and is out of control of the programmer
        // Check if this is a GET with data and needs to be processed by the doGet() method
	
        if (req.getHeader(HttpUtil.HEADER_PARAM_COMMAND) != null ||
            // DoJa will send parameters as QueryString
            req.getQueryString() != null) {
            doGet(req, res);
            return;
        }