我发布了一个question早些时候问为什么我的服务器(用 C++ 和 boost::asio
编写)无法连接到客户端(用 Javascript 编写)。问题是 Javascript Websockets 与 boost::asio
套接字不同吗? boost::asio
不支持 websockets 吗?解决这个问题的最简单方法是什么?
最佳答案
Boost.Beast,现在是 Boost 的一部分,建立在 Boost.Asio 之上,并以您期望的方式工作。它带有示例代码和文档。在这里查看:www.boost.org/libs/beast
这是一个向回显服务器发送消息的完整程序:
#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>
namespace beast = boost::beast; // from <boost/beast.hpp>
namespace http = beast::http; // from <boost/beast/http.hpp>
namespace websocket = beast::websocket; // from <boost/beast/websocket.hpp>
namespace net = boost::asio; // from <boost/asio.hpp>
using tcp = boost::asio::ip::tcp; // from <boost/asio/ip/tcp.hpp>
// Sends a WebSocket message and prints the response
int main(int argc, char** argv)
{
try
{
// Check command line arguments.
if(argc != 4)
{
std::cerr <<
"Usage: websocket-client-sync <host> <port> <text>\n" <<
"Example:\n" <<
" websocket-client-sync echo.websocket.org 80 \"Hello, world!\"\n";
return EXIT_FAILURE;
}
std::string host = argv[1];
auto const port = argv[2];
auto const text = argv[3];
// The io_context is required for all I/O
net::io_context ioc;
// These objects perform our I/O
tcp::resolver resolver{ioc};
websocket::stream<tcp::socket> ws{ioc};
// Look up the domain name
auto const results = resolver.resolve(host, port);
// Make the connection on the IP address we get from a lookup
auto ep = net::connect(ws.next_layer(), results);
// Update the host_ string. This will provide the value of the
// Host HTTP header during the WebSocket handshake.
// See https://tools.ietf.org/html/rfc7230#section-5.4
host += ':' + std::to_string(ep.port());
// Set a decorator to change the User-Agent of the handshake
ws.set_option(websocket::stream_base::decorator(
[](websocket::request_type& req)
{
req.set(http::field::user_agent,
std::string(BOOST_BEAST_VERSION_STRING) +
" websocket-client-coro");
}));
// Perform the websocket handshake
ws.handshake(host, "/");
// Send the message
ws.write(net::buffer(std::string(text)));
// This buffer will hold the incoming message
beast::flat_buffer buffer;
// Read a message into our buffer
ws.read(buffer);
// Close the WebSocket connection
ws.close(websocket::close_code::normal);
// If we get here then the connection is closed gracefully
// The make_printable() function helps print a ConstBufferSequence
std::cout << beast::make_printable(buffer.data()) << std::endl;
}
catch(std::exception const& e)
{
std::cerr << "Error: " << e.what() << std::endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
关于javascript - boost::asio 是否支持 websockets?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/36561179/