HTTP1.0工作原理

Posted 2020-09-08 叶莜落

1.HTTP工作原理

《HTTP响应报文与工作原理详解》讲的比较详细了。

2.示例

（1）server端程序如下：

 1 package org.yeyouluo.demo.jsp;
 2 
 3 import java.io.BufferedReader;
 4 import java.io.BufferedWriter;
 5 import java.io.IOException;
 6 import java.io.InputStreamReader;
 7 import java.io.OutputStreamWriter;
 8 import java.io.PrintWriter;
 9 import java.net.ServerSocket;
10 import java.net.Socket;
11 import java.util.concurrent.ExecutorService;
12 import java.util.concurrent.Executors;
13 
14 /**
15  * 实现HTTP 1.0的服务器，对于所有的HTTP请求，会把HTTP请求头响应回去。
16  * @author yeyouluo
17  *
18  */
19 public class MyHTTPServer {
20 
21     public static void main(String[] args) throws IOException {
22         int port = 80;
23         ServerSocket serverSocket = new ServerSocket(port); 
24         System.out.println("启动服务，绑定端口： " + port);
25         
26         ExecutorService fixedThreadPool = Executors.newFixedThreadPool(30);  //5.线程池
27         
28         //6.这个循环不停监听socket连接，使用SocketHandler处理连入的socket，而这个处理是放在线程池中的。
29         while(true){ 
30             Socket clientSocket = serverSocket.accept();
31             System.out.println("新的连接"+clientSocket.getInetAddress() + ":" + clientSocket.getPort());
32             try{
33                 fixedThreadPool.execute(new SocketHandler(clientSocket));
34             }catch(Exception e){
35                 e.printStackTrace();
36             }
37         }
38     }
39 
40 }
41 
42 class SocketHandler implements Runnable{
43     static final String CRLF = "\\r\\n";  //1.换行符
44     private Socket clientSocket;
45     
46     public SocketHandler(Socket clientSocket) {
47         super();
48         this.clientSocket = clientSocket;
49     }
50     
51     public void handleSocket(Socket clientSocket) throws IOException{
52         BufferedReader in = new BufferedReader(
53                             new InputStreamReader(clientSocket.getInputStream())
54                             );
55         
56         PrintWriter out = new PrintWriter(
57                             new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream()))
58                             ,true);
59         
60         String requestHeader = "";
61         String s;
62         while( (s = in.readLine()) != null ){
63             s +=  CRLF;  //2.很重要，默认情况下in.readLine的结果中\'\\r\\n\'被去掉了
64             requestHeader += s;
65             if( CRLF.equals(s) ){  //如果读取的一行数据只有换行符，说明请求头已经结束了
66                 break;
67             }
68         }
69         
70          System.out.println("客户端请求头：\\n" + requestHeader);
71          
72          String responseBody = "客户端的请求头是：\\n"+requestHeader;
73          String responseHeader = "HTTP/1.0 200 OK\\r\\n" +
74                     "Content-Type: text/plain; charset=UTF-8\\r\\n" +
75                     "Content-Length: "+responseBody.getBytes().length+"\\r\\n" +
76                     "\\r\\n";
77          System.out.println("响应头：\\n" + responseHeader);
78          
79          out.write(responseHeader);
80          out.write(responseBody);
81          out.flush();
82          
83          out.close();
84          in.close();
85          clientSocket.close();
86     }
87     
88     @Override
89     public void run() {
90         try {
91             handleSocket(clientSocket);
92         } catch (IOException e) {
93             // TODO Auto-generated catch block
94             e.printStackTrace();
95         }
96     }
97     
98 }

server端

启动server端。

（2）client端直接通过浏览器或curl工具发送http请求即可。比如在浏览器中输入http://127.0.0.1  。

（3）server端控制台打印如下：

3.参考

http://wiki.jikexueyuan.com/project/java-web/00-02.html