talk.java

有关java 的p2p应用,是一般很好的教程,有兴趣的朋友应该好好阅读一下

/*
 * 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.
 *
 * $Id: talk.java,v 1.65 2005/06/10 01:46:41 hamada Exp $
 */


package net.jxta.impl.shell.bin.talk;

import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ComponentEvent;
import java.awt.event.WindowEvent;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import net.jxta.discovery.DiscoveryEvent;
import net.jxta.discovery.DiscoveryListener;
import net.jxta.discovery.DiscoveryService;
import net.jxta.document.Advertisement;
import net.jxta.document.AdvertisementFactory;
import net.jxta.document.MimeMediaType;
import net.jxta.endpoint.InputStreamMessageElement;
import net.jxta.endpoint.Message;
import net.jxta.endpoint.Message.ElementIterator;
import net.jxta.endpoint.MessageElement;
import net.jxta.endpoint.StringMessageElement;
import net.jxta.id.IDFactory;
import net.jxta.impl.shell.*;
import net.jxta.peergroup.PeerGroup;
import net.jxta.peergroup.PeerGroupID;
import net.jxta.pipe.InputPipe;
import net.jxta.pipe.OutputPipe;
import net.jxta.pipe.PipeID;
import net.jxta.pipe.PipeService;
import net.jxta.protocol.DiscoveryResponseMsg;
import net.jxta.protocol.PipeAdvertisement;

/**
 * talk Shell command: send and receive message from other users.
 *
 */

public class talk extends ShellApp implements Runnable, DiscoveryListener {

    static class ImageWindow extends Frame {

        static ImageWindow currentWin = null;

        Image currentImage = null;
        boolean sizeDone = false;
        public ImageWindow() {
            super();
            enableEvents(WindowEvent.WINDOW_CLOSING |
                         WindowEvent.WINDOW_CLOSED |
                         ComponentEvent.COMPONENT_RESIZED);
        }

        private void initSize(int width, int height) {

            if (sizeDone) {
                return;
            }

            if (width > 640) {
                width = 640;
            } else
                if (width < 100) {
                    width = 100;
                }
            if (height > 480) {
                height = 480;
            } else
                if (height < 100) {
                    height = 100;
                }
            setSize(width, height);
            sizeDone = true;
        }

        public boolean imageUpdate(Image img,
                                   int infoflags,
                                   int x,
                                   int y,
                                   int width,
                                   int height) {


            if ((infoflags & (WIDTH|HEIGHT)) == (WIDTH|HEIGHT)) {
                initSize(width, height);
            }

            // Make sure events keep comming until we have the size done.
            return super.imageUpdate(img, infoflags, x, y, width, height) || !sizeDone;
        }

        private void setImageData(byte[] data) {
            sizeDone = false;
            currentImage = getToolkit().createImage(data);
            // Get the image size.
            int width = currentImage.getWidth(this);
            int height = currentImage.getHeight(this);
            if ((width != -1) && (height != -1)) {
                initSize(width, height);
            }
        }

        // For some reason resizing a frame does not repaint it
        // unless the new size is bigger in both dimensions !
        protected void processComponentEvent(ComponentEvent e) {
            if (e.getID() == ComponentEvent.COMPONENT_RESIZED) {
                repaint();
            }
            super.processComponentEvent(e);
        }

        protected void processWindowEvent(WindowEvent e) {
            if (e.getID() == WindowEvent.WINDOW_CLOSING) {
                dispose();
            } else
                if (e.getID() == WindowEvent.WINDOW_CLOSED) {
                    currentWin = null;
                }
            super.processWindowEvent(e);
        }

        public void paint(Graphics g) {
            if (currentImage != null) {
                if (sizeDone) {
                    g.drawImage(currentImage, 0, 0, getSize().width, getSize().height, this);
                }
            }
        }

        static void showImageFromData(String title, byte[] data) {

            if (currentWin == null) {
                currentWin = new ImageWindow();
                currentWin.pack();
                currentWin.show();
            }
            currentWin.setTitle(title);
            currentWin.setImageData(data);
        }
    }

    private boolean doImages = true;


    private String handleImageFromMsg(String sender, Message msg) {

        String textVersion = "";

        try {

            MessageElement imageElem = msg.getMessageElement("talkx", "image");

            if (imageElem != null) {

                textVersion = "<image>";
                String title = "from " + sender;

                MessageElement captionElem =
                    msg.getMessageElement("talkx", "image_caption");

                if (captionElem != null) {
                    String caption = captionElem.toString();
                    title = title + " : " + caption;
                    textVersion = "<image caption=" + caption + ">";
                }

                if (doImages) {
                    byte[] data = imageElem.getBytes(false);
                    ImageWindow.showImageFromData(title, data);
                    textVersion = "";
                }
            }

        } catch (Exception e) {
            printStackTrace( "failure getting image from message", e );
            doImages = false;
        }

        return textVersion;
    }

    private static final int WaitingTime = 500; // 1/2 second
    private static final int  MAXRETRIES = 20; // 20 times WaitingTime = 10 seconds
    public static final String TalkNameTag = "JxtaTalkUserName";
    public static final String TalkIDTag = "JxtaTalkPipeID";
    private static final String EnvName = "talkd";
    private static final String SenderName = "JxtaTalkSenderName";
    private static final String SenderMessage = "JxtaTalkSenderMessage";
    private static final String SENDERGROUPNAME = "GrpName";

    private DiscoveryService discovery=null;

    private ShellEnv env = null;
    private PipeAdvertisement userAdv = null;
    private String userName = null;
    private Thread thread = null;
    private InputPipe pipeIn = null;

    private List results;

    /**
     *  {@inheritDoc}
     **/
    public int startApp(String[] args) {

        if ((args == null) || (args.length == 0)) {
            return syntaxError();
        }

        env = getEnv();
        discovery= getGroup().getDiscoveryService();

        if (args[0].equals("-register") || args[0].equals("-r")) {
            return registerNewUser(args);
        }

        if (args[0].equals("-login") || args[0].equals("-l")) {
            return login(args);
        }

        if (args[0].equals("-logout") || args[0].equals("-lo")) {
            return logout(args);
        }
        if (args[0].equals("-search") || args[0].equals("-f")) {
            return findUsers();
        }

        return sendMessage(args);
    }


    private boolean deamonRunning(String name) {

        ShellObject obj = env.get(EnvName + "." + name +"@"+(getGroup().getPeerGroupAdvertisement()).getName());
        if (obj == null) {
            return false;
        } else {
            return true;
        }
    }

    private int login(String[] args) {

        if (args.length != 2) {
            return syntaxError();
        }

        String name = args[1];
        if (deamonRunning(name)) {
            consoleMessage( "user " + name + " is already listening");
            return ShellApp.appMiscError;
        }

        PipeAdvertisement adv = findUserAdv(name);

        if (adv == null) {
            consoleMessage( name + " is not a registered user");
            return ShellApp.appMiscError;
        }

        runDeamon(name, adv);

        return ShellApp.appNoError;
    }



    private int findUsers() {