import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.io.PrintStream;

import java.net.ServerSocket;

import java.net.Socket;

public class TcpService {

    public static void main(String[] args) throws Exception {

　　　　　　//建立服务器端ServerSocket对象只需绑定一个端口

          ServerSocket listen = new ServerSocket();

            Socket client  = null;

            Boolean flag = true;

            while(flag){

                System.out.println("Server-->: ");

                client = listen.accept();//通过accept()方法得到连接到次服务器端口对应的客服端Socket

                 new Thread(new ThreadServer(client)).start();

            }

            listen.close();

        }

    }

class ThreadServer implements Runnable{

      private Socket client;  

        public ThreadServer(Socket client){

            this.client = client;

        }  

        @Override

        public void run() {

            BufferedReader buf = null;

            PrintStream out = null;

            try{

                out = new PrintStream(this.client.getOutputStream());

                buf = new BufferedReader(new InputStreamReader(this.client.getInputStream()));  

                boolean flag = true;

                while(flag){

                    String str = buf.readLine();  

                    if(null == str){

                        flag = false;

                    }else{

                        if("bye".equals(str)){

                            flag = false;

                        }else{

                            str = "Respone to client by server:" + str + "\n";out.write(str.getBytes());

                        }

                    }

                }

                this.client.close();

            }catch(Exception e){

                e.printStackTrace();

            }

        }

}

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.PrintStream;

import java.net.Socket;

public class TcpClient {

    public static void main(String[] args)throws IOException{
　　　　　//建立客服端Socket，需写入服务器端主机地址以及服务端口

        Socket client = new Socket("localhost",9999);

        BufferedReader buf = null;

        PrintStream out = null;

        BufferedReader input = null;

        //键盘录入

        input = new BufferedReader(new InputStreamReader(System.in));  
　　　　　//从服务器端得到的输入流

        buf = new BufferedReader(new InputStreamReader(client.getInputStream()));  
　　　　 //输出

        out = new PrintStream(client.getOutputStream());

        //建立标志，用于判断结束会话

        boolean flag = true;

        while(flag){

            System.out.print("Input:");

            String str = input.readLine();

            out.println(str);  

            if("bye".equals(str)){

                flag = false;

            }else{

                String echo = buf.readLine();

                System.out.println(echo);

            }

        }

        buf.close();

        client.close();

    }

}