L'envoi de requête http GET à l'aide de boost::asio, semblable à friser

Je me suis retrouvé aussi travailler avec boost afin d'envoyer des "sur-mesure" requête HTTP GET - j'ai couru le serveur en local sur ma machine Ubuntu (16.04).

Dans mon cas, la demande a été d'une API propriétaire de mon serveur de mise en œuvre (liées à des mots il gardait dans sa base de données), mais vous pouvez modifier le queryStr variable quelle que soit la chaîne de requête que vous souhaitez.

Également, de modifier le argv[1] et argv[2] lorsque vous avez exécuté le programme pour tenir vos valeurs requises (adresse IP, les requêtes, et le port si nécessaire - par défaut est 80).

#include <iostream>
#include <istream>
#include <ostream>
#include <string>
#include <boost/asio.hpp>
using boost::asio::ip::tcp;
using namespace std;
int main(int argc, char* argv[])
{
cout << "main -start" << endl;
try
{
boost::asio::io_service io_service;
string ipAddress = argv[1]; //"localhost" for loop back or ip address otherwise, i.e.- www.boost.org;       
string portNum = argv[2]; //"8000" for instance;
string hostAddress;
if (portNum.compare("80") != 0) //add the ":" only if the port number is not 80 (proprietary port number).
{
hostAddress = ipAddress + ":" + portNum;
}
else 
{ 
hostAddress = ipAddress;
}
string wordToQuery = "aha";
string queryStr = argv[3]; //"/api/v1/similar?word=" + wordToQuery;
//Get a list of endpoints corresponding to the server name.
tcp::resolver resolver(io_service);
tcp::resolver::query query(ipAddress, portNum);
tcp::resolver::iterator endpoint_iterator = resolver.resolve(query);
//Try each endpoint until we successfully establish a connection.
tcp::socket socket(io_service);
boost::asio::connect(socket, endpoint_iterator);
//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 << "GET " << queryStr << " HTTP/1.1\r\n";  //note that you can change it if you wish to HTTP/1.0
request_stream << "Host: " << hostAddress << "\r\n";
request_stream << "Accept: */*\r\n";
request_stream << "Connection: close\r\n\r\n";
//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, "\r\n");
//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/")
{
std::cout << "Invalid response\n";
return 1;
}
if (status_code != 200)
{
std::cout << "Response returned with status code " << status_code << "\n";
return 1;
}
//Read the response headers, which are terminated by a blank line.
boost::asio::read_until(socket, response, "\r\n\r\n");
//Process the response headers.
std::string header;
while (std::getline(response_stream, header) && header != "\r")
{
std::cout << header << "\n";
}
std::cout << "\n";
//Write whatever content we already have to output.
if (response.size() > 0)
{
std::cout << &response;
}
//Read until EOF, writing data to output as we go.
boost::system::error_code error;
while (boost::asio::read(socket, response,boost::asio::transfer_at_least(1), error))
{
std::cout << &response;
}
if (error != boost::asio::error::eof)
{
throw boost::system::system_error(error);
}
}
catch (std::exception& e)
{
std::cout << "Exception: " << e.what() << "\n";
}
return 0;
}

L'exemple d'origine, j'ai suivi est ici: Boost-simple-http-get-request-sync-client

Espère que c'est utile !

Acclamations,

Gars.