java网络编程之socket

基于tcp双向传输，socket编程共用信息流来接收和发送数据。

重点在于理解对不同端来说，输入与输出流的关系。对客户端来说，服务端的输出是客户端的输入。

对服务端来说，客户端的输出是服务端的输入。

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

public class Client {
 
   public static void main(String args[]) throws Exception {
    
      
       //为了简单起见，所有的异常都直接往外抛
       String host = "127.0.0.1";  //要连接的服务端IP地址
       int port = 8899;   //要连接的服务端对应的监听端口
       //与服务端建立连接
       Socket client = new Socket(host, port);
       //建立连接后就可以往服务端写数据了
       BufferedReader is = new BufferedReader(new InputStreamReader(client.getInputStream()));
       
       BufferedReader sin = new BufferedReader(new InputStreamReader(System.in));
       
       
       PrintWriter os = new PrintWriter(client.getOutputStream());
       
       String s;
       s = sin.readLine();
       os.println(s);
       os.flush();
       System.out.println("Server:"+is.readLine());
       
       
       
       os.close();
       is.close();
       client.close();
   }
   
}

 1 import java.io.*;
 2 import java.net.*;
 3 
 4 public class Server {
 5  
 6    public static void main(String args[]) throws IOException {
 7        //端口
 8        int port = 8899;
 9        //建立服务端socket
10        ServerSocket server = new ServerSocket(port);
11        Socket socket = server.accept();
12        
13        BufferedReader is = new BufferedReader(new InputStreamReader(socket.getInputStream()));
14        
15        PrintWriter os = new PrintWriter(socket.getOutputStream());
16        
17        BufferedReader sin = new BufferedReader(new InputStreamReader(System.in));
18        
19        String s = is.readLine();
20        //获取客户端的输入流
21        System.out.println("client:"+s);
22        if(s.equals("hello")){
23            os.println("你好");
24            os.flush();
25        }else{
26            System.out.println("bye");
27        }
28        
29 
30        is.close();
31        os.close();
32        socket.close();
33        server.close();
34    }
35    
36 }