boost执行http的GET请求

boost执行http的GET请求。

//////////////////////////////////////////////////////////////////////////
//#include <libs/asio/example/cpp03/http/client/sync_client.cpp>
//此代码以"boost_1_58_0_7z/libs/asio/example/cpp03/http/client/sync_client.cpp"为蓝本,略作修改.
//////////////////////////////////////////////////////////////////////////

//
// sync_client.cpp
// ~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2015 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) //

#include <iostream>
#include <istream>
#include <ostream>
#include <string>
#include <boost/asio.hpp>

using boost::asio::ip::tcp;

inline int boost_http_sync_client(const std::string& server, const std::string& port, const std::string& path,
std::string& out_response_status_line, std::string& out_response_header, std::string& out_response_data)
{
try
{
boost::asio::io_service io_service;

// Get a list of endpoints corresponding to the server name.
tcp::resolver resolver(io_service);
tcp::resolver::query query(server, port/*"http"*/);
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 " << path/*argv[2]*/ << " HTTP/1.0\r\n";
request_stream << "Host: " << server/*argv[1]*/ << "\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");

if (true)
{
boost::asio::streambuf::const_buffers_type cbt = response.data();
std::string temp_data(boost::asio::buffers_begin(cbt), boost::asio::buffers_end(cbt));
std::size_t idx = temp_data.find('\n');
idx == std::string::npos ? temp_data.size() : idx;
out_response_status_line = temp_data.substr(0, idx + 1);
}

// 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");
if (true)
{
boost::asio::streambuf::const_buffers_type cbt = response.data();
std::string temp_data(boost::asio::buffers_begin(cbt), boost::asio::buffers_end(cbt));
std::size_t idx = temp_data.find("\r\n\r\n");
idx == std::string::npos ? temp_data.length() : idx;
out_response_header = temp_data.substr(0, idx + 2);
}

// 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;
if (true)
{
boost::asio::streambuf::const_buffers_type cbt = response.data();
out_response_data = std::string(boost::asio::buffers_begin(cbt), boost::asio::buffers_end(cbt));
}

// 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;
{
boost::asio::streambuf::const_buffers_type cbt = response.data();
out_response_data += std::string(boost::asio::buffers_begin(cbt), boost::asio::buffers_end(cbt));
}
if (error != boost::asio::error::eof)
throw boost::system::system_error(error);
}
catch (std::exception& e)
{
std::cout << "Exception: " << e.what() << "\n";
return -1;
}

return 0;
}
//////////////////////////////////////////////////////////////////////////
//可以解析下列三种类型的URL:
//http://yunhq.sse.com.cn:32041/v1/sh1/snap/204001?callback=jQuery_test&select=name%2Clast%2Cchg_rate%2Cchange%2Camount%2Cvolume%2Copen%2Cprev_close%2Cask%2Cbid%2Chigh%2Clow%2Ctradephase
//http://hq.sinajs.cn/list=sh204001
//https://www.baidu.com
//////////////////////////////////////////////////////////////////////////
inline int parse_url(const std::string& url, std::string& out_server, std::string& out_port, std::string& out_path)
{
const std::string http___ = "http://";
const std::string https___ = "https://";
std::string temp_data = url;

if (temp_data.find(http___) == 0)
temp_data = temp_data.substr(http___.length());
else if (temp_data.find(https___) == 0)
temp_data = temp_data.substr(https___.length());
else
return -1;

std::size_t idx = temp_data.find('/');
if (std::string::npos == idx)
{
out_path = "/";
idx = temp_data.size();
}
else
{
out_path = temp_data.substr(idx);
}

out_server = temp_data.substr(0, idx);
idx = out_server.find(':');
if (std::string::npos == idx)
{
out_port = "http";
out_port = "80";
}
else
{
out_port = out_server.substr(idx + 1);
out_server = out_server.substr(0, idx);
}

return 0;
}
//
inline int get_url_response(const std::string& url, std::string& out_response_data)
{
int rv = 0;
do
{
std::string server;
std::string port;
std::string path;
rv = parse_url(url, server, port, path);
if (rv) break;
std::string out_response_status_line;
std::string out_response_header;
rv = boost_http_sync_client(server, port, path, out_response_status_line, out_response_header, out_response_data);
if (rv) break;
} while (false);
return rv;
}
//
int parse_hq_sinajs_cn_and_get_last_price(const std::string& market_data, double& last_price)
{
std::string temp_data = market_data;
std::size_t idx;

idx = temp_data.find('"');
if (std::string::npos == idx)
return -1;
temp_data = temp_data.substr(idx + 1);

idx = temp_data.find('"');
if (std::string::npos == idx)
return -1;
temp_data = temp_data.substr(0, idx);

std::vector<std::string> fields;
std::size_t beg_idx, end_idx;
for (beg_idx = end_idx = 0; (end_idx = temp_data.find(',', beg_idx)) != std::string::npos; beg_idx = end_idx + 1)
fields.push_back(temp_data.substr(beg_idx, end_idx - beg_idx));
fields.push_back(temp_data.substr(beg_idx));

if (fields.size() != 33)
return -1;

last_price = atof(fields[3].c_str());

return 0;
}
//
int main()
{
int rv = 0;
std::string url = "http://hq.sinajs.cn/list=sh204001";
std::string response_data;
rv = get_url_response(url, response_data);
if (rv) return -1;
std::cout << response_data << std::endl;

double last_price = 0;
rv = parse_hq_sinajs_cn_and_get_last_price(response_data, last_price);
if (rv) return -1;
std::cout << last_price << std::endl;

return 0;
}
完。

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