通过C++ Boost Websockets进行Watson Text-to-Speech -“未知这样的主机”

Question

我一直无法使用Boost Beast库通过C++中的websockets连接到Watson的文本到语音转换服务

我的代码在80端口上成功地与echo.websocket.org接口，但它不能与Watson的url一起工作。我已经尝试使用协议的变体(http(s)、ws(s)和unspecified (适用于echo.websocket.com))，并且为了确保这一点，我已经尝试了端口80和443。

我能够成功地在Javascript中运行代码，并且使用Firefox的内置网络工具，我已经验证了它在端口443上工作。使用完全相同的URL和端口号可以得到以下结果：“不知道这样的主机。”

下面是正确建立连接的相关JS代码

var completeUrl = "wss://stream.watsonplatform.net/text-to-speech/api/v1/synthesize?access_token=" + accessToken + "&voice=en-US_AllisonVoice";
socket = new WebSocket(completeUrl);

下面的C++代码在理论上可以很好地工作，并且可以在端口80上使用echo.websocket.org，但不能与Watson一起使用。

#include <boost/beast/core.hpp>
#include <boost/beast/websocket.hpp>
#include <boost/asio/connect.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <cstdlib>
#include <iostream>
#include <string>

using tcp = boost::asio::ip::tcp;               // from <boost/asio/ip/tcp.hpp>
namespace websocket = boost::beast::websocket;  // from <boost/beast/websocket.hpp>

// Sends a WebSocket message and prints the response
int main(int argc, char** argv)
{
    try
    {
        std::string accessToken = "XXXXX";
        auto const text = "The quick brown fox jumps over the lazy dog.";

        std::string baseURL = "wss://stream.watsonplatform.net/text-to-speech/api/v1/synthesize";
        std::string voiceModel = "en-US_AllisonVoice";
        auto const port = "443";    // port 80 for echo.websocket.org
                                    // port 443 for watson

        std::string const host = baseURL + "?access_token=" + accessToken + "&voice=" + voiceModel;
        //std::string const host = "echo.websocket.org";

        boost::asio::io_context ioc;
        tcp::resolver resolver{ ioc };
        websocket::stream<tcp::socket> ws{ ioc };

        auto const results = resolver.resolve(host, port);      // Problem line - "resolve: No such host is known"
        std::cout << "Host resolved" << std::endl;

        boost::asio::connect(ws.next_layer(), results.begin(), results.end());
        ws.handshake(host, "/");
        std::cout << "Connection established" << std::endl << "------------------------------" << std::endl;

        ws.write(boost::asio::buffer(std::string(text)));
        std::cout << "Client request: " << text << std::endl;
        boost::beast::multi_buffer buffer;
        ws.read(buffer);
        ws.close(websocket::close_code::normal);

        std::cout << "Server response: " << boost::beast::buffers(buffer.data()) << std::endl;
    }
    catch (std::exception const& e)
    {
        std::cerr << "Error: " << e.what() << std::endl;
        return EXIT_FAILURE;
    }
    return EXIT_SUCCESS;
}

如果Watson URL是错误的，它不应该在Javascript中工作。如果C++代码是错误的，那么它就不能与echo.websocket.org一起工作。所以我不知道问题出在哪里。

Answer 1

代码中的baseURL指定"wss“，这意味着安全的Websockets (SSL)。但是您的stream被删除为一个普通的流。如果您想连接到安全的websocket服务器，那么您的代码应该基于websocket-client-ssl示例：https://github.com/boostorg/beast/blob/d43d9421a40c0251614bc45ea6dcf921a3dbaf37/example/websocket/client/sync-ssl/websocket_client_sync_ssl.cpp#L64