[Other notes] C ++ under Windows network requests

Work using C ++ access a hardware platform on Window System communication library, can only use C ++ to call them to the dll function, and the communication but also to report the data to the backend server, so tidied C ++ under Windows system The method of network request.

 

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The first part: knowledge

Used C ++ basics of points

1.C ++ related

• Class definition
• Function definition
• The constructor and destructor
• #ifdef macros use

2.HTTP related

• http header
• Message format of the difference between GET and POST

 

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Part II: Code

Paste C ++ implementation of a network request code, in fact, the essence is to use Http format messages Socket occur.

1. function claims

• 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. The functions implemented

• HttpConnect.cpp

• WIN32 #ifdef 
  #pragma the Comment (lib, "ws2_32.lib") 
  #endif 
  #include 
  #include 
  #include 
  
  #include "HttpConnect.h" 
  
  HttpConnect :: HttpConnect () 
  { 
  #ifdef WIN32 
      // here you must initialize it, or else gethostbyname been returned empty 
      WSADATA WSA = {0}; 
      WSAStartup (MAKEWORD (2, 2), & WSA); 
  #endif 
  } 
  
  HttpConnect :: ~ HttpConnect () 
  { 
  
  } 
  void HttpConnect :: socketHttp (STD :: String Host, STD: : Request String) 
  { 
      int sockfd; 
      struct the sockaddr_in address; 
      struct the hostent * Server; 
  
      sockfd = Socket (AF_INET, SOCK_STREAM, 0);  
      address.sin_family = AF_INET;
      address.sin_port = the 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());
  }