multiplayerserver.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: MultiPlayerServer.java,v 1.1 2003/05/16 00:16:01 zull Exp $
 */
package com.sun.j2me.blueprints.slugs.server;

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

/**
 * This class implements a generic multiplayer
 * server. The name of the class of the actual
 * game engine is passed in as an argument to
 * the constructor. The server listens for
 * incoming connections, and spawns off
 * ServerConnection instances for each new
 * connection.
 */
public class MultiPlayerServer implements Server, Runnable, 
                                          CommunicationDelegate {
    private GameEngine engine;
    private List list;

    /**
     * Construct a new instance of the server. Create
     * a game engine instance matching game 'game'.
     */
    public MultiPlayerServer(String game) {
        try {
            engine = 
                (GameEngine) Class.forName("com.sun.j2me.blueprints.slugs.server." 
                                           + game + "Engine").newInstance();
        } catch (Exception e) {
            e.printStackTrace();
            System.out.println("*** MultiPlayerServer.MultiPlayerServer(): cannot create engine for '" 
                               + game + "': " + e);
        } 

        engine.setDelegate(this);

        Thread t1 = new Thread(engine);

        t1.start();

        list = new Vector();

        Thread t2 = new Thread(this);

        t2.start();
    }

    /**
     * Distribute game state update to all clients
     */
    public synchronized void distributeUpdate(Frame frame, int frame_no) {
        ServerConnection conn;
        Message msg = new Message(frame_no, frame);

        for (int i = 0; i < list.size(); i++) {
            conn = (ServerConnection) list.get(i);

            conn.sendMessage(msg);
        } 
    } 

    /**
     * Remove a client connection
     */
    public synchronized void removeConnection(ServerConnection conn) {
        list.remove(conn);
        System.out.println("removed connection for player " 
                           + conn.getPlayerID());
        System.out.println("connection list size is now " + list.size());
    } 

    /**
     * main loop
     */
    public void run() {
        ServerSocket socket;

        try {
            socket = new ServerSocket(PORT);

            System.out.println("multiplayer server listening @ " + PORT);

            for (; ; ) {
                if (list.size() >= engine.getMaxPlayerCount()) {
                    // System.out.println("max number of players connected, not currently listening for new connections...");
                    try {
                        Thread.sleep(5000);
                    } catch (InterruptedException e) {}
                } else {
                    synchronized (this) {
                        list.add(new ServerConnection(engine, 
                                                      socket.accept(), this));
                    } 
                } 
            } 
        } catch (IOException ioe) {
            System.out.println("*** MultiPlayerServer.run(): " + ioe);
        } 
    } 

}