HTTP工作原理及HTTP请求、响应报文解读

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我是靠谱客的博主认真爆米花，最近开发中收集的这篇文章主要介绍HTTP工作原理及HTTP请求、响应报文解读，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

一、HTTP原理

1.HTTP工作原理（实例分析）：

<1> http客户端与http服务器建立TCP连接；

<2> http客户端通过浏览器向http服务器80端口发送HTTP连接请求；

<3>如果http服务器允许访问，则返回连接确认，双方建立HTTP连接；

<4>. http客户端发送HTTP页面请求（Http Analyzer V5分析结果）

<5>. http服务器寻找该HTTP文件，如果找到则返回该文件的超文本。http客户端的浏览器对接收到的超文本进行解析，翻译成格式化的页面，显示给用户；

（Http服务器模拟返回）

<6>. http服务器发送完HTTP内容后，断开HTTP连接；

<7>. 双方断开TCP连接；

/*-----------------------------------------------
-------------HTTPServer---------------------
------------------------------------------------*/
#include <winsock2.h>
#include <stdio.h>

int main(void) 
{
	//----------------------
	// Initialize ......
    int len = 0;
    char buff[4096];
    char msgret[4096];
    memset( msgret, 0x00, sizeof(msgret) );

	
	//----------------------
	// Initialize Winsock.
	WSADATA wsaData;
	int iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
	if (iResult != NO_ERROR) {
		printf("Error at WSAStartup()n");
		return 1;
	}

	//----------------------
	// Create a SOCKET for listening for
	// incoming connection requests.
	SOCKET ListenSocket;
	ListenSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (ListenSocket == INVALID_SOCKET) {
		printf("Error at socket(): %ldn", WSAGetLastError());
		WSACleanup();
		return 1;
	}
	
	//----------------------
	// The sockaddr_in structure specifies the address family,
	// IP address, and port for the socket that is being bound.
	sockaddr_in service;
	service.sin_family = AF_INET;
	service.sin_addr.s_addr = inet_addr("10.166.178.225");
	service.sin_port = htons(80);
	
	if (bind( ListenSocket, 
		(SOCKADDR*) &service, 
		sizeof(service)) == SOCKET_ERROR) {
		printf("bind() failed.n");
		closesocket(ListenSocket);
		WSACleanup();
		return 1;
	}
	
	//----------------------
	// Listen for incoming connection requests.
	// on the created socket
	if (listen( ListenSocket, 1 ) == SOCKET_ERROR) 
	{
		printf("Error listening on socket.n");
		closesocket(ListenSocket);
		WSACleanup();
		return 1;
	}

	//----------------------
	// Accept the connection.
	SOCKET AcceptSocket;
	printf("Waiting for client to connect...n");

	while(1)
    {
		AcceptSocket = accept( ListenSocket, NULL, NULL );		
		if (AcceptSocket == INVALID_SOCKET)
		{
			printf("accept failed: %dn", WSAGetLastError());
			closesocket(ListenSocket);
			WSACleanup();
			return 1;
		} 
		else 
		{
			printf("Client connected.n");
			memset( buff, 0x00, sizeof(buff) );
            len = recv(AcceptSocket, buff, 4096, 0);
            printf( "msg recv:n%sn", buff );

            sprintf( msgret, "HTTP/1.1 200 OKn"
				"Date: Fri, 02 Mar 2012 01:59:03 GMTn"
				"Server: Apache"
				"Location: http://www.sina.com.cn/n"
				"Cache-Control: max-age=60n"
				"Expires: Fri, 02 Mar 2012 02:00:03 GMTn"
				"Vary: Accept-Encodingn"
				"Content-Length: 231n"
				"Content-Type: text/html; charset=iso-8859-1n"
				"X-Cache: MISS from xd33-82.HP08040021.sina.com.cnn"
				"Connection: closenn"
				"<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">n"
				"<html><head>n"
				"<title>title test</title>n"
				"</head><body>n"
				"<h1>test body</h1>n"
				"<h2>test sub body</h2>n"
				"<p>My First Test!</p>n"
				"</body></html>" );
				len = send( AcceptSocket, msgret, sizeof(msgret), 0 );
				if( len <= 0 )
				{
					printf( "send failedn" );
				}
		}//end else
    }//end while

	
	// No longer need server socket
	closesocket(ListenSocket);	
	WSACleanup();
	return 0;
}

服务器端的显示结果…

2.HTTP请求(request)&响应(response)报文解读（Http Analyzer V5分析结果）

2.1 HTTP请求报文(Header部分)

GET请求：是以实体的方式得到由请求URL所指定资源的信息，如果请求URL只是一个数据产生过程，那么最终要在响应实体中的是处理过程的结果所指向的资源，而不是处理过程的描述。GET是向服务器发索取数据的一种请求。

[1]GET /HTTP/1.1

[2]Accept:image/gif, Image/x-xbitmap, image/jpeg, Image/pjpeg, application/x-shockwave

-flash, application/x-silverlight,application/vnd.ms-excel, application/vnd.ms-powerpoint,application/msword, */* //客户端可识别的内容类型列表。

[3]Accept-Language:zh-cn 客户端所能解释的语言：简体中文

[4]UA-CPU: x86(上面未体现出来)

[5]Accept-Encoding:gzip, deflate //客户端可以解释的类型

[6]User-Agent:Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; InfoPath.3; .NET CLR2.0.50727; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022; .NET 4.0C; .NET4.0E)

//客户端浏览器型号(同下)