关于java:一对多聊天室

/**
* 实现一对多聊天室的服务端
* 
*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

/**
 * 承受客户端发送音讯的线程类
 */
class ChatReceive extends Thread{
    private Socket socket;

    public ChatReceive(Socket socket){this.socket = socket;}

    @Override
    public void run() {this.receiveMsg();
    }

    /**
     * 实现接管客户端发来的音讯
     */
    private void receiveMsg(){
        BufferedReader br = null;

        try{br = new BufferedReader(new InputStreamReader(socket.getInputStream()));

            while(true){String msg = br.readLine();

                synchronized ("abc"){
                    // 把读取到的数据写入公共数据区
                    ChatRoomServer.buf = "[" + socket.getInetAddress()+ "]" + msg;

                    // 唤醒发送音讯的线程
                    "abc".notifyAll();}
            }
        }catch (Exception e){e.printStackTrace();
        }finally {if(br != null){
                try {br.close();
                } catch (IOException e) {e.printStackTrace();
                }
            }

            if(socket != null){
                try {socket.close();
                } catch (IOException e) {e.printStackTrace();
                }
            }
        }

    }
}

/**
 * 向客户端发送音讯的线程类
 */
class ChatSend extends Thread{
    private Socket socket;

    public ChatSend(Socket socket){this.socket = socket;}
    @Override
    public void run() {this.sendMsg();
    }

    /**
     * 将公共数据区的音讯发送给客户端
     */
    private void sendMsg(){
        PrintWriter pw = null;

        try{pw = new PrintWriter(socket.getOutputStream());

            while(true){synchronized ("abc"){
                    // 让发送音讯的线程处于期待状态
                    "abc".wait();

                    pw.println(ChatRoomServer.buf);
                    pw.flush();}
            }
        }catch (Exception e){e.printStackTrace();
        }finally {if(pw != null){pw.close();
            }
            if(socket != null){
                try {socket.close();
                } catch (IOException e) {e.printStackTrace();
                }
            }
        }
    }
}
public class ChatRoomServer {
    // 定义公共数据区
    public static String buf;

    public static void main(String[] args) {System.out.println("Chat Server Version 1.0");
        System.out.println("Listen at 8888....");

        ServerSocket serverSocket = null;

        try{serverSocket = new ServerSocket(8888);
            while(true){Socket socket = serverSocket.accept();
                System.out.println("连贯到：" + socket.getInetAddress());

                new ChatReceive(socket).start();
                new ChatSend(socket).start();}
        }catch (Exception e){e.printStackTrace();
        }finally {if(serverSocket != null){
                try {serverSocket.close();
                } catch (IOException e) {e.printStackTrace();
                }
            }
        }
    }
}

/**
* 实现一对多聊天室的客户端
* 
*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

/**
 * 发送音讯线程
 */
class Send extends Thread{
    private Socket socket;
    private Scanner scanner;
    private String name;

    public Send(Socket socket,Scanner scanner,String name){super(name);
        this.socket = socket;
        this.scanner = scanner;
    }

    /**
     * 发送音讯办法
     */
    private void sendMsg(){
        PrintWriter pw = null;

        try{pw = new PrintWriter(socket.getOutputStream());

            while(true){System.out.print("\n 请"+this.getName()+"输出音讯：");

                String msg = scanner.nextLine();

                pw.println(msg);
                pw.flush();}
        }catch (Exception e){e.printStackTrace();
        }finally {if(pw != null){pw.close();
            }
            if(scanner != null){scanner.close();
            }
            if(socket != null){
                try {socket.close();
                } catch (IOException e) {e.printStackTrace();
                }
            }
        }
    }

    @Override
    public void run() {this.sendMsg();
    }
}

/**
 * 承受音讯线程
 */
class Receive extends Thread{
    private Socket socket;
    private String name;

    public Receive(Socket socket,String name){super(name);
        this.socket = socket;
    }

    /**
     * 承受音讯办法
     */
    private void receiveMsg(){
        BufferedReader br = null;

        try{br = new BufferedReader(new InputStreamReader(socket.getInputStream()));

            while(true){String msg = br.readLine();

                System.out.println("\n" + this.getName() + "承受信息为：" + msg);
            }
        }catch (Exception e){e.printStackTrace();
        }finally {if(br != null){
                try {br.close();
                } catch (IOException e) {e.printStackTrace();
                }
            }
            if(socket != null){
                try {socket.close();
                } catch (IOException e) {e.printStackTrace();
                }
            }
        }
    }

    @Override
    public void run() {this.receiveMsg();
    }
}
public class ChatRoomClient {public static void main(String[] args) {
        Scanner scanner = null;
        ServerSocket serverSocket = null;
        Socket socket = null;

        try{
            // 创立 Scanner 对象
            scanner = new Scanner(System.in);
            System.out.println("请输出：Server,<port> 或者：<ip>,<port>");

            String str = scanner.nextLine();

            String[] arrStr = str.split(",");

            if("Server".equals(arrStr[0])){
                // 启动服务端
                System.out.println("TCP Server Listen at" + arrStr[1] + "...");

                serverSocket = new ServerSocket(Integer.parseInt(arrStr[1]));

                socket = serverSocket.accept();

                System.out.println("连贯胜利!");


            }else{
                // 启动客户端
                socket = new Socket(arrStr[0],Integer.parseInt(arrStr[1]));
                System.out.println("连贯胜利");
            }

            new Send(socket,scanner,arrStr[0]).start();
            new Receive(socket,arrStr[0]).start();}catch (Exception e){e.printStackTrace();
        }finally {if(serverSocket != null){
                try {serverSocket.close();
                } catch (IOException e) {e.printStackTrace();
                }
            }
        }
    }
}