c/c++语言开发共享使用boost.asio实现网络通讯

#include <boost/asio.hpp>  #define using_ssl   //是否加密  #ifdef using_ssl #include <boost/asio/ssl.hpp>   #endif  using boost::asio::ip::tcp; using std::string;  int post(const string& host, const string& port, const string& page, const string& data, string& reponse_data) {   try   {     boost::asio::io_service io_service;     //如果io_service存在复用的情况    // if(io_service.stopped())    //   io_service.reset();      // 从dns取得域名下的所有ip     tcp::resolver resolver(io_service);     tcp::resolver::query query(host, port);     tcp::resolver::iterator endpoint_iterator = resolver.resolve(query);   	// 尝试连接到其中的某个ip直到成功  #ifdef using_ssl 	boost::asio::ssl::context context(boost::asio::ssl::context::sslv23);  	context.set_default_verify_paths();  	boost::asio::ssl::stream<boost::asio::ip::tcp::socket> socket(io_service, context);  	socket.set_verify_mode(boost::asio::ssl::context::verify_none); 	boost::asio::connect(socket.lowest_layer(), endpoint_iterator); 	socket.handshake(boost::asio::ssl::stream_base::client); #else 	tcp::socket socket(io_service); 	boost::asio::connect(socket, endpoint_iterator); #endif      // form the request. we specify the "connection: close" header so that the     // server will close the socket after transmitting the response. this will     // allow us to treat all data up until the eof as the content.     boost::asio::streambuf request;     std::ostream request_stream(&request);  	request_stream << "post " << page << " http/1.1rn";     request_stream << "host: " << host << "rn";     request_stream << "content-length: " << data.length() << "rn";     // content-type: 视实际情况修改，or“application/octet-stream”     request_stream << "content-type: application/json; charset=utf-8rn"; 	request_stream << "accept: */*rn";     request_stream << "connection: closernrn";     request_stream << data;      // send the request.     boost::asio::write(socket, request);      // read the response status line. the response streambuf will automatically     // grow to accommodate the entire line. the growth may be limited by passing     // a maximum size to the streambuf constructor.     boost::asio::streambuf response;     boost::asio::read_until(socket, response, "rn");      // check that response is ok.     std::istream response_stream(&response);     std::string http_version;     response_stream >> http_version;     unsigned int status_code;     response_stream >> status_code;     std::string status_message;     std::getline(response_stream, status_message);     if (!response_stream || http_version.substr(0, 5) != "http/")     {       reponse_data = "invalid response";       return -2;     }     // 如果服务器返回非200都认为有错,不支持301/302等跳转     if (status_code != 200)     { 		std::stringstream oss; 		oss << "response returned with status code" << " : " << status_code; 		reponse_data = oss.str();         return -3;     }      // 传说中的包头可以读下来了     std::string header;     std::vector<string> headers;         //		string content_length_header("content-length: "); //		size_t content_length = 0;     while (std::getline(response_stream, header) && header != "r") 	{ 		/*	if(string::npos != header.find(content_length_header)) 			{ 				string tmp(header.substr(content_length_header.size())); 				stringstream ss; 				ss << tmp; 				ss >> content_length; 			}*/       headers.push_back(header); 	  //std::cout << header << std::endl; 	}      // 读取所有剩下的数据作为包体     boost::system::error_code error;     while (boost::asio::read(socket, response,         boost::asio::transfer_at_least(1), error))     {                }  	// 返回值为eof,认为是正确的 	if (error != boost::asio::error::eof && error.value() != 0x140000db) 	{ 		std::stringstream oss; 		oss << error.value() << " : " <<  error.message(); 		reponse_data = oss.str(); 		return -4; 	}      //响应有数据     if (response.size())     {       std::istream response_stream(&response);       std::istreambuf_iterator<char> eos;       reponse_data = string(std::istreambuf_iterator<char>(response_stream), eos);                             }   }   catch(std::exception& e)   {     reponse_data = e.what();       return -1;     }   return 0; }