C++ 使用boost库实现http client get操作

Posted 2023-01-11 软件工程小施同学

I found myself also working with boost in order to send some "customized" HTTP GET request - I ran the server locally on my Ubuntu machine (16.04).

In my case the request was of some proprietary API my server implemented (related to words it kept in its data base), but you can modify the queryStr variable to hold whatever query string you wish for.

Also, change the argv[1] and argv[2] when you ran the program to hold your required values (IP address, query, and port if needed - default is 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;

c++ - Sending http GET request using boost::asio, similar to cURL - Stack Overflowhttps://stackoverflow.com/questions/28728347/sending-http-get-request-using-boostasio-similar-to-curl