用java实现简单TCP服务器监听

---------------------------------------------服务端-----------------------------------------------

 1 package C;
import java.io.*;
import java.net.*;

public class Server extends ServerSocket            
{
    public Server(int serverPort) throws IOException
    {
        super(serverPort);
        try
        {
            while (true)
            {
                Socket socket = accept();
                new ServerThread(socket);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        finally {
            close();
        }
    }
    class ServerThread extends Thread       /*建立服务端线程*/
    {
        private Socket socket;
        private BufferedReader in;
        private PrintWriter out;
        public ServerThread(Socket s) throws IOException
        {
            this.socket = s;
            in = new BufferedReader(new InputStreamReader(
                    socket.getInputStream(), "GB2312"));        /*国标码*/
            out = new PrintWriter(socket.getOutputStream(),true);
            start();                /*开始线程*/
        }

        public void run()
        {
                    try {
                while (true)
                {
                    String line = in.readLine();
                    if ("finish".equals(line))
                    {
                        System.out.println("服务器已停止监听");
                        break;
                    }
                    System.out.println("接收到的数据：" + line);
                    String msg = "'" + line + "'已传输到服务器端.";
                    out.println(msg);
                    out.flush();
                }
                out.close();
                in.close();
                socket.close();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
        }
    }
        public static void main(String[] args) throws IOException
        {
            System.out.println("服务器开始运行......");
            new Server(2333);       /*绑定端口号*/
        }

}

---------------------------------------------客户端-----------------------------------------------

 1 package C;
import java.io.*;
import java.net.*;

    public class Client
    {
        private Socket socket;                  /*定义socket连接*/
        private BufferedReader reader;          /*从字符输入流读取文本*/
        private PrintWriter writer;             /*打印到文本输出流*/

        public Client(int serverPort) {                 /*定义客户端端口号*/
            try {                                                       /*抛异常*/
                socket = new Socket("123.206.78.55", serverPort);
                reader = new BufferedReader(
                        new InputStreamReader(socket.getInputStream()));        /*标准输入输出流*/
                writer = new PrintWriter(socket.getOutputStream());

                while (true)
                {

                    BufferedReader in = new BufferedReader(
                            new InputStreamReader(System.in));
                    String message = in.readLine();
                    writer.println(message);
                    writer.flush();                             /*不关闭流，清空输入缓存区*/

                    if ("finish".equals(message))
                    {
                        System.out.println("服务器已停止监听");
                        break;
                    }
                    String received = reader.readLine();
                    System.out.println(received);
                }

                writer.close();
                reader.close();            /*关闭流*/
                socket.close();

            }
            catch (UnknownHostException ex)
            {
                ex.printStackTrace();
            }
            catch (IOException ex)
            {
                ex.printStackTrace();       /*在命令行打印异常信息在程序中出错的位置及原因*/
            }
        }



        public static void main(String[] args)
        {
             new Client(2333);      /*绑定端口号*/
        }
    }

服务端是通过客户端的流式输入来实现监听和停止监听的。