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。
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
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/1.0rn"; stream << "Host: "<< host << "rn"; stream << "User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3rn"; stream << "Content-Type:application/x-www-form-urlencodedrn"; stream << "Content-Length:" << post_content.length()<<"rn"; stream << "Connection:closernrn"; 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/1.0rn"; stream << "Host: " << host << "rn"; stream <<"User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.9.2.3) Gecko/20100401 Firefox/3.6.3rn"; stream <<"Connection:closernrn"; socketHttp(host, stream.str()); }