问题:
websocket 客户端(POCO 1.5.1，c++)不会连接到 websocket c# 服务器(带有 Fleck 库的命令行应用程序)。达到超时并抛出异常:
Cannot upgrade to WebSocket connection: OK
Exception Code: 1
Poco WebException Documentation
WS_ERR_NO_HANDSHAKE = 1 :
No Connection: Upgrade or Upgrade: websocket header in handshake request.
事实 1:此 websocket 客户端将连接到 Ruby Event Machine websocket 服务器。
事实 2:javascript 客户端将连接到 websocket c# 服务器。
事实 3:相同的 javascript 客户端 也将连接到 websocket ruby 服务器。
事实 4:websocket 客户端 不会连接到附近的 Alchemy Websocket 服务器。 https://github.com/Olivine-Labs/Alchemy-Websockets
使用 Wireshark 更新 POCO正在使用 GET/HTTP/1.0\r\n
Javascript 版本: GET/HTTP/1.1\r\n
所有源代码
c++ 客户端代码
#include "Game.h"
#include <irrlicht.h>
#include "driverChoice.h"
#include <iostream>
#include <assert.h>
#include "Poco/Net/WebSocket.h"
#include "Poco/Net/HTTPClientSession.h"
#include "Poco/Net/HTTPRequest.h"
#include "Poco/Net/HTTPResponse.h"
#include "Poco/Net/ServerSocket.h"
#include "Poco/Net/NetException.h"
#include "Poco/Exception.h"
using Poco::Net::HTTPClientSession;
using Poco::Net::HTTPRequest;
using Poco::Net::HTTPResponse;
using Poco::Net::HTTPServerRequest;
using Poco::Net::HTTPServerResponse;
using Poco::Net::WebSocket;
using Poco::Net::WebSocketException;
using Poco::Exception;
// VS2010
// POCO 1.5.1
// Irrlicht 3D engine
// Windows 7 Enterprise edition
Game::Game(void)
{
}
Game::~Game(void)
{
}
//...
void Game::TestWebSocketClient()
{
char buffer[1024];
int flags;
int n;
std::string payload;
try
{
HTTPClientSession cs("localhost", 8080);
HTTPRequest request(HTTPRequest::HTTP_GET, "/ws");
HTTPResponse response;
std::string cmd;
WebSocket * ws = new WebSocket(cs, request, response); // Causes the timeout
payload = "SGClient: Hello World!";
ws->sendFrame(payload.data(), payload.size(), WebSocket::FRAME_TEXT);
n = ws->receiveFrame(buffer, sizeof(buffer), flags);
while( cmd != "exit")
{
cmd = "";
std::cin >> cmd;
ws->sendFrame(cmd.data(), cmd.size(), WebSocket::FRAME_TEXT);
n = ws->receiveFrame(buffer, sizeof(buffer), flags);
if( n > 0 )
{
std::cout << buffer << std::endl;
}
}
ws->shutdown();
}
catch (Exception ex)
{
return;
}
c# 中的服务器代码
// vs2010
// fleck library
// Windows 7 enterprise edition
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;
using Fleck;
using System.Timers;
namespace TestWebsocket
{
class Program
{
static void Main()
{
FleckLog.Level = LogLevel.Debug;
var allSockets = new List<IWebSocketConnection>();
var server = new WebSocketServer("ws://localhost:8080");
server.Start(socket =>
{
socket.OnOpen = () =>
{
Console.WriteLine("Open!");
allSockets.Add(socket);
};
socket.OnClose = () =>
{
Console.WriteLine("Close!");
allSockets.Remove(socket);
};
socket.OnMessage = message =>
{
Console.WriteLine(message);
allSockets.ToList().ForEach(s => s.Send("Echo: " + message));
};
});
var input = Console.ReadLine();
while (input != "exit")
{
foreach (var socket in allSockets.ToList())
{
socket.Send(input);
}
input = Console.ReadLine();
}
}
}
}
备用 HTML/Javascript 客户端代码，在 Chrome 版本 31.0.1650.57 m 中运行
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>websocket client</title>
<script type="text/javascript">
var start = function () {
var inc = document.getElementById('incomming');
var wsImpl = window.WebSocket || window.MozWebSocket;
var form = document.getElementById('sendForm');
var input = document.getElementById('sendText');
inc.innerHTML += "connecting to server ..<br/>";
// create a new websocket and connect
window.ws = new wsImpl('ws://localhost:8080/');
// when data is comming from the server, this metod is called
ws.onmessage = function (evt) {
inc.innerHTML += evt.data + '<br/>';
};
// when the connection is established, this method is called
ws.onopen = function () {
inc.innerHTML += '.. connection open<br/>';
};
// when the connection is closed, this method is called
ws.onclose = function () {
inc.innerHTML += '.. connection closed<br/>';
}
form.addEventListener('submit', function(e){
e.preventDefault();
var val = input.value;
ws.send(val);
input.value = "";
});
}
window.onload = start;
</script>
</head>
<body>
<form id="sendForm">
<input id="sendText" placeholder="Text to send" />
</form>
<pre id="incomming"></pre>
</body>
</html>
使用在命令行界面上运行的 eventmachine 的备用 ruby 服务器代码
// Ruby 1.9
// gem install em-websocket required.
require 'em-websocket'
EventMachine::WebSocket.start(:host => "localhost", :port => 8080) do |ws|
ws.onopen { ws.send "RS: Hello Client!"}
ws.onmessage {
|msg| ws.send "RS: Pong: #{msg}"
puts msg
}
ws.onclose { puts "WebSocket closed" }
end
最佳答案
问题是 POCO 默认的 HTTP 请求版本是 1.0。
RFC 规范的第 4.1 节指出最小值为 1.1:
https://www.rfc-editor.org/rfc/rfc6455#section-4.1
- The method of the request MUST be GET, and the HTTP version MUST be at least 1.1. For example, if the WebSocket URI is "ws://example.com/chat", the first line sent should be "GET /chat HTTP/1.1".
通过以下方式替换 HTTPRequest 结构解决了问题:
HTTPRequest request(HTTPRequest::HTTP_GET, "/ws", "HTTP/1.1" );
干杯!
关于c# - POCO 1.5.1 Websocket 客户端无法连接到 c# websocket 服务器，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/20181080/