I just started learning Rest Api and Retrofit package. I am creating HotelApp for practice and i need to get data models list from Api.

我刚开始学习Rest Api和Retrofit包。我创建的实践HotelApp，我需要从API获取数据模型列表。

I think i did everything as needed, but terminal throws an exception "Error has occured", it means no data has recieved from API Model. I guess i did something wrong when i was creating a models.

我想我已经按要求做了所有的事情，但是终端抛出了一个异常：Error Have Are Are，这意味着没有从API Model接收到数据。我想我在做模特的时候做错了什么。

At first i made an ApiService to get data from my API.

首先，我创建了一个ApiService来从我的API获取数据。

part 'api_service.g.dart';

// API URL
@RestApi(baseUrl: 'https://run.mocky.io/v3/35e0d18e-2521-4f1b-a575-f0fe366f66e3/')

abstract class ApiService {
  factory ApiService(Dio dio) = _ApiService;

  @GET('/hotels')
  Future<List<HotelModel>> getHotels();
}

Api Data Model. I used quicktype.io, so maybe it made a mistake when it was converting api into dart code.

API数据模型。我使用的是icktype.io，所以在将API转换为DART代码时可能会出错。

@JsonSerializable()
class HotelModel {
  int id;
  String name;
  String adress;
  int minimalPrice;
  String priceForIt;
  int rating;
  String ratingName;
  List<String> imageUrls;
  AboutTheHotel aboutTheHotel;

  HotelModel({
    required this.id,
    required this.name,
    required this.adress,
    required this.minimalPrice,
    required this.priceForIt,
    required this.rating,
    required this.ratingName,
    required this.imageUrls,
    required this.aboutTheHotel,
  });

  factory HotelModel.fromJson(Map<String, dynamic> json) => _$HotelModelFromJson(json);
  Map<String, dynamic> toJson() => _$HotelModelToJson(this);
}

@JsonSerializable()
class AboutTheHotel {
  String description;
  List<String> peculiarities;

  AboutTheHotel({
    required this.description,
    required this.peculiarities,
  });

  factory AboutTheHotel.fromJson(Map<String, dynamic> json) => _$AboutTheHotelFromJson(json);

  //     AboutTheHotel(
  //   description: json["description"],
  //   peculiarities: List<String>.from(json["peculiarities"].map((x) => x)),
  // );

  Map<String, dynamic> toJson() => _$AboutTheHotelToJson(this);
  //     {
  //   "description": description,
  //   "peculiarities": List<dynamic>.from(peculiarities.map((x) => x)),
  // };
}

FutureBuilder created inside body parameter inside Scaffold. It throws an exception inside if hasData block.

在脚手架内创建了内部实体参数FutureBuilder。它在if hasData块内部抛出异常。

FutureBuilder _body() {
    final apiService =
        ApiService(Dio(BaseOptions(contentType: "application/json")));
    return FutureBuilder(
      future: apiService.getHotels(),
      builder: (context, snapshots) {
        if (snapshots.connectionState == ConnectionState.done) {
          if (snapshots.hasData) {                                // exception happens here 
            final List<HotelModel> hotels = snapshots.data!;
            return _hotels(hotels);
          } else {
            return const Center(
              child: Text(
                  "Error has occurred"),
            );
          }
        } else {
          return const Center(
            child: CircularProgressIndicator(),
          );
        }
      },
    );
  }