【其他笔记】Windows下的C++网络请求

工作使用了C++在Window系统上接入一个硬件平台的通信库，只能使用C++去调用他们给的dll函数，而且通信后还要把数据上报到后台服务器，所以整理了一下C++在Windows系统下网络请求方法。

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第一部分 ： 知识点

用到的C++基础知识点

1.C++相关

• 类定义
• 函数定义
• 构造函数与析构函数
• #ifdef宏的使用

2.HTTP相关

• http报文头
• GET与POST的报文格式区别

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第二部分 ： 代码

贴上C++实现的网络请求代码，其实本质就是利用Socket发生Http格式报文。

1.功能声明

• HttpConnect.h

• class HttpConnect {
      public:
          void socketHttp(std::string host, std::string request);
          
          void postData(std::string host, std::string path, std::string post_content);
          
          void getData(std::string host, std::string path, std::string get_content);
          
          HttpConnect();
          
          ~HttpConnect();
  };
              

2.功能实现

• HttpConnect.cpp

• #ifdef WIN32
  #pragma comment(lib,"ws2_32.lib")
  #endif
  #include 
  #include 
  #include 
  
  #include "HttpConnect.h"
  
  HttpConnect::HttpConnect()
  {
  #ifdef WIN32
      // 此处一定要初始化一下，否则gethostbyname返回一直为空
      WSADATA wsa = { 0 };
      WSAStartup(MAKEWORD(2, 2), &wsa);
  #endif
  }
  
  HttpConnect::~HttpConnect()
  {
  
  }
  void HttpConnect::socketHttp(std::string host, std::string request)
  {
      int sockfd;
      struct sockaddr_in address;
      struct hostent *server;
  
      sockfd = socket(AF_INET,SOCK_STREAM,0);
      address.sin_family = AF_INET;
      address.sin_port = htons(8091);
      server = gethostbyname(host.c_str());
      memcpy((char *)&address.sin_addr.s_addr,(char*)server->h_addr, server->h_length);
  
      if(-1 == connect(sockfd,(struct sockaddr *)&address,sizeof(address))){
          std::cout <<"connection error!"<<std::endl;
          return;
      }
  
      std::cout << request << std::endl;
  #ifdef WIN32
      send(sockfd, request.c_str(),request.size(),0);
  #else
      write(sockfd,request.c_str(),request.size());
  #endif
      char buf[1024*1024] = {0};
  
  
      int offset = 0;
      int rc;
  
  #ifdef WIN32
      while(rc = recv(sockfd, buf+offset, 1024,0))
  #else
      while(rc = read(sockfd, buf+offset, 1024))
  #endif
      {
          offset += rc;
      }
  
  #ifdef WIN32
      closesocket(sockfd);
  #else
      close(sockfd);
  #endif
      buf[offset] = 0;
      std::cout << buf << std::endl;
  }
  
  void HttpConnect::postData(std::string host, std::string path, std::string post_content)
  {
      // POST请求方式
      std::stringstream stream;
      stream << "POST " << path;
      stream << " HTTP/1.0\r\n";
      stream << "Host: "<< host << "\r\n";
      stream << "User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3\r\n";
      stream << "Content-Type:application/x-www-form-urlencoded\r\n";
      stream << "Content-Length:" << post_content.length()<<"\r\n";
      stream << "Connection:close\r\n\r\n";
      stream << post_content.c_str();
      
      socketHttp(host, stream.str());
  }
  
  void HttpConnect::getData(std::string host, std::string path, std::string get_content)
  {
      // GET请求方式
      std::stringstream stream;
      stream << "GET " << path << "?" << get_content;
      stream << " HTTP/1.0\r\n";
      stream << "Host: " << host << "\r\n";
      stream <<"User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3\r\n";
      stream <<"Connection:close\r\n\r\n";
  
      socketHttp(host, stream.str());
  }