未处理的异常:http://10.5.11.88:7777/socketcluster/#‘的WebSocketException:连接没有升级到websocket

Question

这是我的客户端代码，服务器在c++中。但是当我试图连接这个客户端到服务器时，它抛出了一个websocket没有升级的错误。服务器正在运行，我已经与js客户端检查过了。

客户端代码

import 'package:socketcluster_client/socketcluster_client.dart';
import 'dart:async';

class MyListener extends BasicListener {
@override
void onAuthentication(Socket socket, bool status) {
print('onAuthentication: socket $socket status $status');
}

@override
void onConnectError(Socket socket, e) {
print('onConnectError: socket $socket e $e');
}

@override
void onConnected(Socket socket) {
print('onConnected: socket $socket');
new Timer.periodic(const Duration(seconds: 2), (_) {
print('Attempting to send');
  socket.emit('sampleClientEvent',
      {'message': 'This is an object with a message property'});
});
}

@override
void onDisconnected(Socket socket) {
print('onDisconnected: socket $socket');
}

@override
void onSetAuthToken(String token, Socket socket) {
print('onSetAuthToken: socket $socket token $token');
socket.authToken = token;
}
}

main() async {
var socket = await Socket.connect('ws://10.5.11.88:7777/socketcluster/',
listener: new MyListener());
socket.on('rand', (name, data, ack) {
print('got message $data from event $name');
ack(name, 'No error', 'Hi there buddy');
});
}

我试过https://github.com/flutter/flutter/issues/11444，但它不起作用。

错误日志

Launching lib\main.dart on AOSP on IA Emulator in debug mode...
Running Gradle task 'assembleDebug'...
√ Built build\app\outputs\apk\debug\app-debug.apk.
Installing build\app\outputs\apk\app.apk...
Syncing files to device AOSP on IA Emulator...
E/flutter ( 5399): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled 
Exception: WebSocketException: Connection to 
'http://10.5.11.88:7777/socketcluster/#' was not upgraded to websocket
E/flutter ( 5399): #0      _WebSocketImpl.connect.<anonymous closure>.error 
(dart:_http/websocket_impl.dart:1054:9)
E/flutter ( 5399): #1      _WebSocketImpl.connect.<anonymous closure> 
(dart:_http/websocket_impl.dart:1063:14)
E/flutter ( 5399): #2      _rootRunUnary (dart:async/zone.dart:1134:38)
E/flutter ( 5399): #3      _CustomZone.runUnary 
(dart:async/zone.dart:1031:19)
E/flutter ( 5399): #4      _FutureListener.handleValue 
(dart:async/future_impl.dart:139:18)
E/flutter ( 5399): #5      Future._propagateToListeners.handleValueCallback 
(dart:async/future_impl.dart:680:45)
E/flutter ( 5399): #6      Future._propagateToListeners 
(dart:async/future_impl.dart:709:32)
E/flutter ( 5399): #7      Future._completeWithValue 
(dart:async/future_impl.dart:524:5)
E/flutter ( 5399): #8      Future.wait.<anonymous closure> 
(dart:async/future.dart:400:22)
E/flutter ( 5399): #9      _rootRunUnary (dart:async/zone.dart:1134:38)
E/flutter ( 5399): #10     _CustomZone.runUnary 
(dart:async/zone.dart:1031:19)
E/flutter ( 5399): #11     _FutureListener.handleValue 
(dart:async/future_impl.dart:139:18)
E/flutter ( 5399): #12     Future._propagateToListeners.handleValueCallback 
(dart:async/future_impl.dart:680:45)
E/flutter ( 5399): #13     Future._propagateToListeners 
(dart:async/future_impl.dart:709:32)
E/flutter ( 5399): #14     Future._completeWithValue 
(dart:async/future_impl.dart:524:5)
E/flutter ( 5399): #15     Future._asyncComplete.<anonymous closure> 
(dart:async/future_impl.dart:554:7)
E/flutter ( 5399): #16     _rootRun (dart:async/zone.dart:1126:13)
E/flutter ( 5399): #17     _CustomZone.run (dart:async/zone.dart:1023:19)
E/flutter ( 5399): #18     _CustomZone.runGuarded 
(dart:async/zone.dart:925:7)
E/flutter ( 5399): #19     _CustomZone.bindCallbackGuarded.<anonymous 
closure> (dart:async/zone.dart:965:23)
E/flutter ( 5399): #20     _microtaskLoop 
(dart:async/schedule_microtask.dart:43:21)
E/flutter ( 5399): #21     _startMicrotaskLoop 
(dart:async/schedule_microtask.dart:52:5)
E/flutter ( 5399): 

Answer 1

实际上，在AWS/server上采用了严格的应用负载均衡策略，解决了这一问题。