/*源程序清單8-20*/

import java.io.*;
import java.net.*;

public class ServerClient
{

  public ServerClient(int port)
  {
    Server server=new Server(port);
    server.start();
    Client client=new Client(port);
    client.start();
  }

  public static void main(String[] args)
  {
    new ServerClient(7777);
  }
}

//服務器線程
class Server extends Thread
{
  //使用端口號
  int port;
  ServerSocket server;
  Socket socket;
  //服務器輸出流
  DataOutputStream outStream=null;
  //服務器輸入流
  DataInputStream inStream=null;

  public Server(int port)
  {
    try
    {
      this.port=port;
      server=new ServerSocket(port);
    }
    catch(Exception e)
    {
      System.out.println(e.toString());
    }
  }

  public void run()
  {
    try
    {
      //監聽用戶連接
      socket=server.accept();
      outStream=new DataOutputStream(socket.getOutputStream());
      inStream=new DataInputStream(socket.getInputStream());
      //服務器準備好，可以進行通訊
      System.out.println("server is ok,please continue!");
      while(true)
      {
        //讀取從客戶端發送的信息
        String str=inStream.readUTF();
        System.out.println("The server receive String:"+str);
        //將信息重新向客戶端發送
        outStream.writeUTF(str);
      }
    }
    catch(Exception e)
    {
      System.out.println(e.toString());
    }
  }
}

class Client extends Thread
{
  //指定通訊端口 
  int port;
  Socket socket;
  DataInputStream inStream=null;
  DataOutputStream outStream=null;

  public Client(int port)
  {
    try
    {
      this.port=port;
      //建立同本地機子的socket連接
      socket=new Socket(InetAddress.getLocalHost(),port);
      inStream=new DataInputStream(socket.getInputStream());
      outStream=new DataOutputStream(socket.getOutputStream());
      //客戶端準備好，可以進行通訊
      System.out.println("client is ok,please continue!");
    }
    catch(Exception e)
    {
      System.out.println(e.toString());
    }
  }
  public void run()
  {
    try
    {
      while(true)
      {
        byte[] b=new byte[1024];
        String str="";
        //從鍵盤讀取字符串
        int m=System.in.read(b);
        str=new String(b,0,0,m-1);
        //向服務器發送信息
        outStream.writeUTF(str);
        //從服務器讀取信息
        str=inStream.readUTF();
        System.out.println("The client receive String:"+str);
      }
    }
    catch(Exception e)
    {
      System.out.println(e.toString());
    }
  }
}