Java study 2:The note of studying Socket which based TCP

1. TCP concept:

　　　　　　传输控制协议（Transmission Control Protocol, TCP）是一种面向连接（连接导向）的、可靠的、基于字节流的运输层（Transport layer）通信协议，由IETF的RFC 793说明（specified）。(from bing)

　　2、TCP program:
　　　　　　(1)、有明确的C/S之分，Server端用ServerSocket,Client端用Socke;

　　　　　　(2)、Server端用accept()做監聽等待接收，一旦有鏈接連上的話，返回一個Socket對象作爲Client

　　　　　　(3)、C/S都是用getInputStream/getOutputStream來讀取/寫入message

下面上代碼：

 1 import java.io.BufferedReader;
 2 import java.io.IOException;
 3 import java.io.InputStreamReader;
 4 import java.io.PrintWriter;
 5 import java.net.ServerSocket;
 6 import java.net.Socket;
 7
 8 public class ServerCode {
 9     private static int port =4444;
10     static Socket cs;
11     public static void main(String[] args) throws IOException {
12         ServerSocket ss=new ServerSocket(port);
13         cs=ss.accept();
14         System.out.println("Accept :"+cs);
15         try{
16             BufferedReader br=new BufferedReader(new InputStreamReader(cs.getInputStream()));
17             PrintWriter pr=new PrintWriter(cs.getOutputStream(),true);
18             while(true){
19                 String str=br.readLine();
20                 if(str.equals("bye")){
21                     break;
22                 }
23                 System.out.println("Client->Server:"+str);
24                 pr.println("send back to client:"+str);
25             }
26             br.close();
27             pr.close();
28         }catch(Exception e){
29             System.out.println("error:"+e);
30         }finally{
31             System.out.println("close the Server socket and the io.");
32             cs.close();
33             ss.close();
34         }
35
36     }
37
38 }

ServerCode

 1 import java.io.BufferedReader;
 2 import java.io.IOException;
 3 import java.io.InputStreamReader;
 4 import java.io.PrintWriter;
 5 import java.net.InetAddress;
 6 import java.net.Socket;
 7
 8 public class ClientCode {
 9     public static void main(String[] args) throws IOException {
10         InetAddress add=InetAddress.getByName("localhost");
11         Socket cs=new Socket(add,4444);
12         System.out.println("socket = " + cs);
13         try{
14             BufferedReader br=new BufferedReader(new InputStreamReader(cs.getInputStream()));
15             PrintWriter pw=new PrintWriter(cs.getOutputStream(),true);
16             pw.println("Hello I‘m qixi");
17             String str=br.readLine();
18             System.out.println(str);
19             pw.println("bye");
20         }catch(Exception e){
21             System.out.println(e);
22         }finally{
23             System.out.println("close the Client socket and the io.");
24             cs.close();
25         }
26     }
27 }

ClientCode