socket编程实现HTTP请求

利用c++语言+socket实现HTTP请求，请求获得的数据效果图如下：

HTTP协议的下一层是TCP，根据HTTP协议只需要利用TCP发送下面的数据到达目标主机，目标主机就会发送相应的数据到客户端。

代码截图：

特别注意每一行末的\r\n

下面是代码实现：

//mySocket.h头文件

#include <Winsock2.h>
#include <Windows.h>
#include <Ws2tcpip.h>
#pragma comment(lib, "ws2_32.lib")
#include <string>
using namespace std;

//只是对Socket中使用TCP协议的一种封装
class MySocket{
public:
    static int InitClient(SOCKET *sock, string ip, int port);
    static int CloseMySocket(SOCKET *Sock);
    static int SendData(SOCKET sock, const string data);
    static int RecvData(SOCKET sock, string &data);
};

//mySocket.c源码文件

 #include "mySocket.h" 

 //只是对Socket中使用TCP协议的封装

 int MySocket::InitClient(SOCKET *sock, string ip, int port)
 {
     WSADATA wsaData;//初始化wsaData
     if (WSAStartup(MAKEWORD(, ), &wsaData) != )
     {
         return -;
     }

     //创建套接字
     if ((*sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == INVALID_SOCKET)
     {
         WSACleanup();
         return -;
     }

     struct sockaddr_in serverAddr;
     serverAddr.sin_family = AF_INET;
     serverAddr.sin_port = htons(port);
     serverAddr.sin_addr.s_addr = inet_addr(ip.c_str());

     if (connect(*sock, (struct sockaddr *)&serverAddr, sizeof(serverAddr)) == SOCKET_ERROR)
     {
         return -;
     }

     return ;
 }

 int MySocket::CloseMySocket(SOCKET *sock)
 {
     if (closesocket(*sock) == SOCKET_ERROR)
     {
         WSACleanup();
         return -;
     }
     return  ;
 }

 int MySocket::RecvData(SOCKET sock, string &data)
 {
     int bufLen = ;
     char buf[];
     int recvLen= ;
     int iResult;
     buf[bufLen] = '\0';
     while (true)
     {
         iResult = recv(sock, buf, bufLen, );
         if (iResult < )
         {
             data = "";
             return -;
         }

         recvLen += iResult;

         if (iResult == )
         {
             return recvLen;
         }

         if (iResult == bufLen)
         {
             data += buf;
             ZeroMemory(buf, bufLen);
             continue;
         }
         if (iResult >  && iResult < bufLen)
         {
             data += buf;
             return recvLen;
         }
     }
 }

 int MySocket::SendData(SOCKET sock, const string data)
 {
     int iResult = send(sock, data.c_str(), data.length(), );
     if (iResult == SOCKET_ERROR) {
         MySocket::CloseMySocket(&sock);
         WSACleanup();
         return -;
     }

     return ;
 }

//main函数

#include <stdio.h>
#include <iostream>
#include<time.h>
#include "mySocket.h"
using namespace std;
int main()
{
    SOCKET clientSock;
    string str;
    int iResult;
    if (MySocket::InitClient(&clientSock, "42.121.254.229", ) == -)//主机IP地址+端口号
    {
        printf("连接失败\n");
        return -;
    }
    string head = "GET / HTTP/1.1\r\n";
    head.append("Host: m.cnblogs.com\r\n");//请求的域名
    head.append("Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8\r\n");
    head.append("User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/37.0.2062.120 Safari/537.36\r\n");
    head.append("Accept-Language: zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3\r\n");
    head.append("Accept-Charset: GB2312,utf-8;q=0.7,*;q=0.7");
    head.append("Accept-Encoding: gzip,deflate\r\n");
    head.append("\r\n");//表明请求头结束了
    iResult = MySocket::SendData(clientSock, head);
    if (iResult == -)
    {
        printf("发送数据失败\n");
        return -;
    }
    iResult = MySocket::RecvData(clientSock, str);

    if (iResult  == -)
    {
        printf("接受数据失败\n");
        return -;
    }
    printf("----接受数据长度:%d----\n", iResult);
    printf(str.c_str());
    MySocket::CloseMySocket(&clientSock);
    return ;
}

如果请求别的网站，有可能连返回的数据全部是乱码，那就是网站启用了gzip压缩了。

图中截图中文乱码，是因为返回的是UTF-8编码的字符，控制台默认是已GBK编码显示的。