serverconnection.java

这是我编写的第一个J2ME程序

/*
 * Copyright (c) 2002, 2003 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:
 * - Redistribution of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * - Redistribution 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.
 * Neither the name of Sun Microsystems, Inc., 'Java', 'Java'-based
 * names, or the names of contributors may be used to endorse or promote
 * products derived from this software without specific prior written
 * permission.
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
 * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
 * MIDROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
 * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
 * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
 * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
 * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
 * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * You acknowledge that this software is not designed, licensed or
 * intended for use in the design, construction, operation or maintenance
 * of any nuclear facility. $Id: ServerConnection.java,v 1.2 2003/05/29 22:39:15 wildcard Exp $
 */
package com.sun.j2me.blueprints.slugs.server;

import com.sun.j2me.blueprints.slugs.shared.*;
import java.io.*;
import java.net.*;

/**
 * Instances of this class track client
 * connections for the server.
 */
public class ServerConnection implements Runnable {
    private MultiPlayerServer server;
    private Socket socket;
    private DataInputStream in;
    private DataOutputStream out;
    private GameEngine engine;
    private int player_id;
    private Message err;
    private boolean done;

    /**
     * Create a new instance for use with game engine 'engine',
     * socket 'socket', and server 'server'.
     */
    public ServerConnection(GameEngine engine, Socket socket, 
                            MultiPlayerServer server) {
        this.server = server;
        this.socket = socket;
        this.engine = engine;
        done = false;
        err = new Message(Message.ALL_FRAMES, Message.ERROR, 0);

        Thread thread = new Thread(this);

        thread.start();
    }

    private synchronized void handleSignup() {
        player_id = engine.addPlayer();

        if (player_id < 0) {
            System.out.println("ServerConnection.handleSignup(): engine refused player sign-up");
            handleError();

            return;
        } 

        System.out.println("signed up player " + player_id);

        Message msg = new Message(Message.ALL_FRAMES, Message.SIGNUP_ACK, 
                                  player_id);

        try {
            msg.archive(out);
        } catch (IOException e) {
            System.out.println("***: could not send msg " + err);
        } 
    } 

    private void handleClientStatus(Message msg) {
        engine.updatePlayer(msg.getFrameNumber(), player_id, 
                            msg.getBody()[0]);
    } 

    public int getPlayerID() {
        return player_id;
    } 

    private void handleSignoff() {
        engine.removePlayer(player_id);

        done = true;
    } 

    private void handleError() {
        try {
            err.archive(out);
        } catch (IOException e) {
            System.out.println("***: could not send msg " + err);
        } 

        done = true;
    } 

    /**
     * Send a message to the client connected to this instance
     */
    public synchronized void sendMessage(Message msg) {
        try {
            msg.archive(out);
        } catch (IOException e) {
            System.out.println("***: could not send msg " + msg);
        } 
    } 

    /**
     * main loop
     */
    public void run() {
        Message msg;

        try {
            in = new DataInputStream(socket.getInputStream());
            out = new DataOutputStream(socket.getOutputStream());

            while (!done) {
                msg = Message.createFromStream(in);

                switch (msg.getType()) {

                case Message.SIGNUP:
                    handleSignup();

                    break;

                case Message.CLIENT_STATUS:
                    handleClientStatus(msg);

                    break;

                case Message.SIGNOFF:
                    handleSignoff();

                    break;

                default:
                    handleError();

                    break;
                }
            } 

            in.close();
            out.close();
            socket.close();
        } catch (Exception ioe) {
            System.out.println("*** ServerConnection.run(): " + ioe);
            server.removeConnection(this);
        } 

        handleSignoff();
        server.removeConnection(this);
        System.out.println("player " + player_id + " disconnected.");
    } 

}