not upgraded to websocket

[VishalKumarMauray]

Unhandled Exception: WebSocketException: Connection to 'https://testing.lm25aarogyaindia.com:0/ws#' was not upgraded to websocket

• using java as backend

java code:-
@configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {

@Override
public void configureMessageBroker(MessageBrokerRegistry config) {
    config.enableSimpleBroker("/notifications");
    config.setApplicationDestinationPrefixes("/app");
}

@Override
public void registerStompEndpoints(StompEndpointRegistry registry) {
    registry.addEndpoint("/ws");
    registry.addEndpoint("/ws").withSockJS();
}

}

flutter code:-
import 'package:flutter/material.dart';
import 'package:web_socket_channel/web_socket_channel.dart';

void main() => runApp(const MyApp());

class MyApp extends StatelessWidget {
const MyApp({super.key});

@OverRide
Widget build(BuildContext context) {
const title = 'WebSocket Demo';
return const MaterialApp(
title: title,
home: MyHomePage(
title: title,
),
);
}
}

class MyHomePage extends StatefulWidget {
const MyHomePage({
super.key,
required this.title,
});

final String title;

@OverRide
State createState() => _MyHomePageState();
}

class _MyHomePageState extends State {
final TextEditingController _controller = TextEditingController();
final _channel = WebSocketChannel.connect(
Uri.parse('wss://echo.websocket.events'),
);

@OverRide
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Padding(
padding: const EdgeInsets.all(20),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Form(
child: TextFormField(
controller: _controller,
decoration: const InputDecoration(labelText: 'Send a message'),
),
),
const SizedBox(height: 24),
StreamBuilder(
stream: _channel.stream,
builder: (context, snapshot) {
return Text(snapshot.hasData ? '${snapshot.data}' : '');
},
)
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _sendMessage,
tooltip: 'Send message',
child: const Icon(Icons.send),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}

void _sendMessage() {
if (_controller.text.isNotEmpty) {
_channel.sink.add(_controller.text);
}
}

@OverRide
void dispose() {
_channel.sink.close();
_controller.dispose();
super.dispose();
}
}

it is connecting to echo server without any error but when i change the url to the desired one it shows the error

[ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: WebSocketException: Connection to 'https://testing.lm25aarogyaindia.com:0/ws#' was not upgraded to websocket

[VishalKumarMauray]

web_socket_channel: ^2.4.0

i am using this version of the package

[Mae623]

I meet this question, too. Then I find there is a bug in my server. Hoping my experience will help you.

[VishalKumarMauray]

which type of bug you find in your server will you please guide for my project.