Type 'Example' is not a subtype of type 'Example' of 'example' - flutter

Question

I'm beginning with this language and trying to create an application that can receive messages from a server (via websocket) and display them in a ListView.
I created a class in a dedicated file to transform this messages into entities.
But it seems, from the trace, that the class type I use in several files doesn't seem to be... "the same".
The trace :
E/flutter ( 9655): [ERROR:flutter/lib/ui/ui_dart_state.cc(157)] Unhandled Exception: type 'Example' is not a subtype of type 'Example' of 'example' where
E/flutter ( 9655): Example is from package:exampleProject/components/Example.dart
E/flutter ( 9655): Example is from package:exampleProject/components/example.dart
E/flutter ( 9655):
E/flutter ( 9655): #0 Plugin._onMessageReceived.<anonymous closure> (package:exampleProject/plugin.dart:35:15)
E/flutter ( 9655): #1 Iterable.forEach (dart:core/iterable.dart:279:30)
E/flutter ( 9655): #2 Plugin._onMessageReceived (package:exampleProject/plugin.dart:31:16)
E/flutter ( 9655): #3 WebSocketsNotifications._onReceptionOfMessageFromServer.<anonymous closure> (package:exampleProject/websockets.dart:95:15)
E/flutter ( 9655): #4 Iterable.forEach (dart:core/iterable.dart:279:30)
E/flutter ( 9655): #5 WebSocketsNotifications._onReceptionOfMessageFromServer (package:exampleProject/websockets.dart:94:16)
E/flutter ( 9655): #6 _rootRunUnary (dart:async/zone.dart:1134:38)
E/flutter ( 9655): #7 _CustomZone.runUnary (dart:async/zone.dart:1031:19)
E/flutter ( 9655): #8 _CustomZone.runUnaryGuarded (dart:async/zone.dart:933:7)
E/flutter ( 9655): #9 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:338:11)
E/flutter ( 9655): #10 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:265:7)
E/flutter ( 9655): #11 _ForwardingStreamSubscription._add (dart:async/stream_pipe.dart:134:11)
E/flutter ( 9655): #12 _ForwardingStream._handleData (dart:async/stream_pipe.dart:100:10)
E/flutter ( 9655): #13 _ForwardingStreamSubscription._handleData (dart:async/stream_pipe.dart:166:13)
E/flutter ( 9655): #14 _rootRunUnary (dart:async/zone.dart:1134:38)
E/flutter ( 9655): #15 _CustomZone.runUnary (dart:async/zone.dart:1031:19)
E/flutter ( 9655): #16 _CustomZone.runUnaryGuarded (dart:async/zone.dart:933:7)
E/flutter ( 9655): #17 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:338:11)
E/flutter ( 9655): #18 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:265:7)
E/flutter ( 9655): #19 _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:766:19)
E/flutter ( 9655): #20 _StreamController._add (dart:async/stream_controller.dart:642:7)
E/flutter ( 9655): #21 _rootRunUnary (dart:async/zone.dart:1134:38)
E/flutter ( 9655): #22 _CustomZone.runUnary (dart:async/zone.dart:1031:19)
E/flutter ( 9655): #23 _CustomZone.runUnaryGuarded (dart:async/zone.dart:933:7)
E/flutter ( 9655): #24 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:338:11)
E/flutter ( 9655): #25 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:265:7)
E/flutter ( 9655): #26 _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:766:19)
E/flutter ( 9655): #27 _StreamController._add (dart:async/stream_controller.dart:642:7)
E/flutter ( 9655): #28 _StreamController.add (dart:async/stream_controller.dart:588:5)
E/flutter ( 9655): #29 new _WebSocketImpl._fromSocket.<anonymous closure> (dart:_http/websocket_impl.dart:1143:21)
E/flutter ( 9655): #30 _rootRunUnary (dart:async/zone.dart:1134:38)
E/flutter ( 9655): #31 _CustomZone.runUnary (dart:async/zone.dart:1031:19)
E/flutter ( 9655): #32 _CustomZone.runUnaryGuarded (dart:async/zone.dart:933:7)
E/flutter ( 9655): #33 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:338:11)
E/flutter ( 9655): #34 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:265:7)
E/flutter ( 9655): #35 _SinkTransformerStreamSubscription._add (dart:async/stream_transformers.dart:70:11)
E/flutter ( 9655): #36 _EventSinkWrapper.add (dart:async/stream_transformers.dart:17:11)
E/flutter ( 9655): #37 _WebSocketProtocolTransformer._messageFrameEnd (dart:_http/websocket_impl.dart:336:22)
E/flutter ( 9655): #38 _WebSocketProtocolTransformer.add (dart:_http/websocket_impl.dart:231:46)
E/flutter ( 9655): #39 _SinkTransformerStreamSubscription._handleData (dart:async/stream_transformers.dart:122:24)
E/flutter ( 9655): #40 _rootRunUnary (dart:async/zone.dart:1134:38)
E/flutter ( 9655): #41 _CustomZone.runUnary (dart:async/zone.dart:1031:19)
E/flutter ( 9655): #42 _CustomZone.runUnaryGuarded (dart:async/zone.dart:933:7)
E/flutter ( 9655): #43 _BufferingStreamSubscription._sendData (dart:async/stream_impl.dart:338:11)
E/flutter ( 9655): #44 _BufferingStreamSubscription._add (dart:async/stream_impl.dart:265:7)
E/flutter ( 9655): #45 _SyncStreamControllerDispatch._sendData (dart:async/stream_controller.dart:766:19)
E/flutter ( 9655): #46 _StreamController._add (dart:async/stream_controller.dart:642:7)
E/flutter ( 9655): #47 _StreamController.add (dart:async/stream_controller.dart:588:5)
E/flutter ( 9655): #48 _Socket._onData (dart:io-patch/socket_patch.dart:1831:41)
E/flutter ( 9655): #49 _rootRunUnary (dart:async/zone.dart:1138:13)
E/flutter ( 9655): #50 _CustomZone.runUn
Here's my entity class :
// example.dart
class Example {
String name;
Example.fromJson(Map<String, dynamic> decodedJson) {
name = decodedJson['name'];
}
}
Here's the plugin that communicates with the socket manager and receives messages from it AND transforms the content into an entity :
// plugin.dart
import 'dart:convert';
import 'package:flutter/foundation.dart';
import 'package:exampleProject/websockets.dart';
import 'package:exampleProject/components/Example.dart';
Plugin plugin = new Plugin();
class Plugin {
static final Plugin _plugin = new Plugin._internal();
factory Plugin() => _plugin;
Plugin._internal() {
// Initialize sockets
sockets.initCommunication();
sockets.addListener(_onMessageReceived);
}
_onMessageReceived(message) {
Map<String, dynamic> decodedJson = json.decode(message);
_listeners.forEach((Function callback) {
// --------------------------------------------------------------< Creating the class instance
Example example = Example.fromJson(decodedJson);
// --------------------------------------------------------------< Send it to listeners
callback(example);
});
}
ObserverList<Function> _listeners = new ObserverList<Function>();
addListener(Function callback) {
_listeners.add(callback);
}
removeListener(Function callback) {
_listeners.remove(callback);
}
}
My main :
// main.dart
import 'package:flutter/material.dart';
import 'package:exampleProject/websockets.dart';
import 'package:exampleProject/plugin.dart';
import 'package:exampleProject/components/Example.dart';
void main() => runApp(App());
class App extends StatefulWidget {
#override
_AppState createState() => _AppState();
}
class _AppState extends State<App> {
// --------------------------------------------------------------< List
List<Example> examples = [];
#override
void initState() {
super.initState();
plugin.addListener(_onMessageReceived);
}
#override
void dispose() {
plugin.removeListener(_onMessageReceived);
super.dispose();
}
// --------------------------------------------------------------< List insert
_onMessageReceived(Example example) {
examples.insert(0, example);
// Force render
setState(() {});
}
[...]
}
What did I miss ?
Thank you in advance for your help

Answer 1

This line:
import 'package:exampleProject/components/Example.dart';
should be:
import 'package:exampleProject/components/example.dart';
since that's what it's called. The class name is Example but the file name is not.