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

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(2, 2), &wsaData) != 0)
    {
        return -1;
    }

    //创建套接字
    if ((*sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == INVALID_SOCKET)
    {
        WSACleanup();
        return -1;
    }

    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 -1;
    }

    return 0;
}

int MySocket::CloseMySocket(SOCKET *sock)
{
    if (closesocket(*sock) == SOCKET_ERROR)
    {
        WSACleanup();
        return -1;
    }
    return 0 ;
}

int MySocket::RecvData(SOCKET sock, string &data)
{
    int bufLen = 255;
    char buf[256];
    int recvLen= 0;
    int iResult;
    buf[bufLen] = '';
    while (true)
    {
        iResult = recv(sock, buf, bufLen, 0);
        if (iResult < 0)
        {
            data = "";
            return -1;
        }

        recvLen += iResult;

        if (iResult == 0)
        {
            return recvLen;
        }

        if (iResult == bufLen)
        {
            data += buf;
            ZeroMemory(buf, bufLen);
            continue;
        }
        if (iResult > 0 && iResult < bufLen)
        {
            data += buf;
            return recvLen;
        }
    }
}

int MySocket::SendData(SOCKET sock, const string data)
{
    int iResult = send(sock, data.c_str(), data.length(), 0);
    if (iResult == SOCKET_ERROR) {
        MySocket::CloseMySocket(&sock);
        WSACleanup();
        return -1;
    }

    return 0;
}

//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", 80) == -1)//主机IP地址+端口号
    {
        printf("连接失败
");
        return -1;
    }
    string head = "GET / HTTP/1.1
";
    head.append("Host: m.cnblogs.com
");//请求的域名
    head.append("Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
");
    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
");
    head.append("Accept-Language: zh-cn,zh;q=0.8,en-us;q=0.5,en;q=0.3
");
    head.append("Accept-Charset: GB2312,utf-8;q=0.7,*;q=0.7");
    head.append("Accept-Encoding: gzip,deflate
");
    head.append("
");//表明请求头结束了
    iResult = MySocket::SendData(clientSock, head);
    if (iResult == -1)
    {
        printf("发送数据失败
");
        return -1;
    }
    iResult = MySocket::RecvData(clientSock, str);
    
    if (iResult  == -1)
    {
        printf("接受数据失败
");
        return -1;
    }
    printf("----接受数据长度:%d----
", iResult);
    printf(str.c_str());
    MySocket::CloseMySocket(&clientSock);
    return 0;
}

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。