有人可以帮我用这个复杂的 json 来飞镖吗

Question

我从这个链接https://itunes.apple.com/in/rss/topalbums/limit=25/json得到一个json响应 任何人都可以制作一个模型类，我可以在其中发出 http 获取请求并在未来的构建器中使用快照数据。我尝试了 quicktype 但模型类抛出 null 之类的错误不是字符串的子类型

Answer 1

是的。在模型中转换 JSON 并在代码中使用它始终是一个好习惯。

class AppleModel {
  Feed? feed;

  AppleModel({this.feed});

  AppleModel.fromJson(Map<String, dynamic> json) {
    feed = json['feed'] != null ? new Feed.fromJson(json['feed']) : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.feed != null) {
      data['feed'] = this.feed!.toJson();
    }
    return data;
  }
}

class Feed {
  Author? author;
  Entry? entry;
  Name? updated;
  Name? rights;
  Name? title;
  Name? icon;
  List<Link>? link;
  Name? id;

  Feed(
      {this.author,
      this.entry,
      this.updated,
      this.rights,
      this.title,
      this.icon,
      this.link,
      this.id});

  Feed.fromJson(Map<String, dynamic> json) {
    author =
        json['author'] != null ? new Author.fromJson(json['author']) : null;
    entry = json['entry'] != null ? new Entry.fromJson(json['entry']) : null;
    updated =
        json['updated'] != null ? new Name.fromJson(json['updated']) : null;
    rights = json['rights'] != null ? new Name.fromJson(json['rights']) : null;
    title = json['title'] != null ? new Name.fromJson(json['title']) : null;
    icon = json['icon'] != null ? new Name.fromJson(json['icon']) : null;
    if (json['link'] != null) {
      link = <Link>[];
      json['link'].forEach((v) {
        link!.add(new Link.fromJson(v));
      });
    }
    id = json['id'] != null ? new Name.fromJson(json['id']) : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.author != null) {
      data['author'] = this.author!.toJson();
    }
    if (this.entry != null) {
      data['entry'] = this.entry!.toJson();
    }
    if (this.updated != null) {
      data['updated'] = this.updated!.toJson();
    }
    if (this.rights != null) {
      data['rights'] = this.rights!.toJson();
    }
    if (this.title != null) {
      data['title'] = this.title!.toJson();
    }
    if (this.icon != null) {
      data['icon'] = this.icon!.toJson();
    }
    if (this.link != null) {
      data['link'] = this.link!.map((v) => v.toJson()).toList();
    }
    if (this.id != null) {
      data['id'] = this.id!.toJson();
    }
    return data;
  }
}

class Author {
  Name? name;
  Name? uri;

  Author({this.name, this.uri});

  Author.fromJson(Map<String, dynamic> json) {
    name = json['name'] != null ? new Name.fromJson(json['name']) : null;
    uri = json['uri'] != null ? new Name.fromJson(json['uri']) : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.name != null) {
      data['name'] = this.name!.toJson();
    }
    if (this.uri != null) {
      data['uri'] = this.uri!.toJson();
    }
    return data;
  }
}

class Name {
  String? label;

  Name({this.label});

  Name.fromJson(Map<String, dynamic> json) {
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['label'] = this.label;
    return data;
  }
}

class Entry {
  Name? imName;
  List<ImImage>? imImage;
  Name? imItemCount;
  ImImage? imPrice;
  ImContentType? imContentType;
  Name? rights;
  Name? title;
  ImContentType? link;
  Name? id;
  ImImage? imArtist;
  ImContentType? category;
  ImImage? imReleaseDate;

  Entry(
      {this.imName,
      this.imImage,
      this.imItemCount,
      this.imPrice,
      this.imContentType,
      this.rights,
      this.title,
      this.link,
      this.id,
      this.imArtist,
      this.category,
      this.imReleaseDate});

  Entry.fromJson(Map<String, dynamic> json) {
    imName =
        json['im:name'] != null ? new Name.fromJson(json['im:name']) : null;
    if (json['im:image'] != null) {
      imImage = <ImImage>[];
      json['im:image'].forEach((v) {
        imImage!.add(new ImImage.fromJson(v));
      });
    }
    imItemCount = json['im:itemCount'] != null
        ? new Name.fromJson(json['im:itemCount'])
        : null;
    imPrice = json['im:price'] != null
        ? new ImImage.fromJson(json['im:price'])
        : null;
    imContentType = json['im:contentType'] != null
        ? new ImContentType.fromJson(json['im:contentType'])
        : null;
    rights = json['rights'] != null ? new Name.fromJson(json['rights']) : null;
    title = json['title'] != null ? new Name.fromJson(json['title']) : null;
    link =
        json['link'] != null ? new ImContentType.fromJson(json['link']) : null;
    id = json['id'] != null ? new Name.fromJson(json['id']) : null;
    imArtist = json['im:artist'] != null
        ? new ImImage.fromJson(json['im:artist'])
        : null;
    category = json['category'] != null
        ? new ImContentType.fromJson(json['category'])
        : null;
    imReleaseDate = json['im:releaseDate'] != null
        ? new ImImage.fromJson(json['im:releaseDate'])
        : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.imName != null) {
      data['im:name'] = this.imName!.toJson();
    }
    if (this.imImage != null) {
      data['im:image'] = this.imImage!.map((v) => v.toJson()).toList();
    }
    if (this.imItemCount != null) {
      data['im:itemCount'] = this.imItemCount!.toJson();
    }
    if (this.imPrice != null) {
      data['im:price'] = this.imPrice!.toJson();
    }
    if (this.imContentType != null) {
      data['im:contentType'] = this.imContentType!.toJson();
    }
    if (this.rights != null) {
      data['rights'] = this.rights!.toJson();
    }
    if (this.title != null) {
      data['title'] = this.title!.toJson();
    }
    if (this.link != null) {
      data['link'] = this.link!.toJson();
    }
    if (this.id != null) {
      data['id'] = this.id!.toJson();
    }
    if (this.imArtist != null) {
      data['im:artist'] = this.imArtist!.toJson();
    }
    if (this.category != null) {
      data['category'] = this.category!.toJson();
    }
    if (this.imReleaseDate != null) {
      data['im:releaseDate'] = this.imReleaseDate!.toJson();
    }
    return data;
  }
}

class ImImage {
  String? label;
  Attributes? attributes;

  ImImage({this.label, this.attributes});

  ImImage.fromJson(Map<String, dynamic> json) {
    label = json['label'];
    attributes = json['attributes'] != null
        ? new Attributes.fromJson(json['attributes'])
        : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['label'] = this.label;
    if (this.attributes != null) {
      data['attributes'] = this.attributes!.toJson();
    }
    return data;
  }
}

class Attributes {
  String? height;

  Attributes({this.height});

  Attributes.fromJson(Map<String, dynamic> json) {
    height = json['height'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['height'] = this.height;
    return data;
  }
}

class Attributes {
  String? amount;
  String? currency;

  Attributes({this.amount, this.currency});

  Attributes.fromJson(Map<String, dynamic> json) {
    amount = json['amount'];
    currency = json['currency'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['amount'] = this.amount;
    data['currency'] = this.currency;
    return data;
  }
}

class ImContentType {
  ImContentType? imContentType;
  Attributes? attributes;

  ImContentType({this.imContentType, this.attributes});

  ImContentType.fromJson(Map<String, dynamic> json) {
    imContentType = json['im:contentType'] != null
        ? new ImContentType.fromJson(json['im:contentType'])
        : null;
    attributes = json['attributes'] != null
        ? new Attributes.fromJson(json['attributes'])
        : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.imContentType != null) {
      data['im:contentType'] = this.imContentType!.toJson();
    }
    if (this.attributes != null) {
      data['attributes'] = this.attributes!.toJson();
    }
    return data;
  }
}

class ImContentType {
  Attributes? attributes;

  ImContentType({this.attributes});

  ImContentType.fromJson(Map<String, dynamic> json) {
    attributes = json['attributes'] != null
        ? new Attributes.fromJson(json['attributes'])
        : null;
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    if (this.attributes != null) {
      data['attributes'] = this.attributes!.toJson();
    }
    return data;
  }
}

class Attributes {
  String? term;
  String? label;

  Attributes({this.term, this.label});

  Attributes.fromJson(Map<String, dynamic> json) {
    term = json['term'];
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['term'] = this.term;
    data['label'] = this.label;
    return data;
  }
}

class Attributes {
  String? rel;
  String? type;
  String? href;

  Attributes({this.rel, this.type, this.href});

  Attributes.fromJson(Map<String, dynamic> json) {
    rel = json['rel'];
    type = json['type'];
    href = json['href'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['rel'] = this.rel;
    data['type'] = this.type;
    data['href'] = this.href;
    return data;
  }
}

class Attributes {
  String? imId;

  Attributes({this.imId});

  Attributes.fromJson(Map<String, dynamic> json) {
    imId = json['im:id'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['im:id'] = this.imId;
    return data;
  }
}

class Attributes {
  String? href;

  Attributes({this.href});

  Attributes.fromJson(Map<String, dynamic> json) {
    href = json['href'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['href'] = this.href;
    return data;
  }
}

class Attributes {
  String? imId;
  String? term;
  String? scheme;
  String? label;

  Attributes({this.imId, this.term, this.scheme, this.label});

  Attributes.fromJson(Map<String, dynamic> json) {
    imId = json['im:id'];
    term = json['term'];
    scheme = json['scheme'];
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final Map<String, dynamic> data = new Map<String, dynamic>();
    data['im:id'] = this.imId;
    data['term'] = this.term;
    data['scheme'] = this.scheme;
    data['label'] = this.label;
    return data;
  }
}

此外，您可以使用 github.io 将其转换为 Dart 对象。请随时根据需要以其他方式对上述 Attributes 模型进行更改。

Answer 2

这是一个相当大的 json 文件。如果您只对其中的一部分感兴趣，则不必解析每个对象。相反，请使用 deep_pick 选择您需要的值。

这个例子解析了多个专辑

import 'package:http/http.dart' as http;
import 'package:deep_pick/deep_pick.dart';

Future<void> main() async {
  final response = await http.get(Uri.parse('https://itunes.apple.com/in/rss/topalbums/limit=10/json'));
  final albums = pickFromJson(response.body, 'feed', 'entry').asListOrEmpty((pick) => Album.fromPick(pick));
  print(albums);
}

class Album {
  final Uri? link;
  final String? name;
  final String? artist;
  final DateTime? releaseDate;

  factory Album.fromPick(Pick pick) {
    return Album(
      link: pick('link', 0, 'attributes', 'href').letOrNull((it) => Uri.parse(it.asStringOrThrow())),
      name: pick('im:name').asStringOrNull(),
      artist: pick('im:artist', 'label').asStringOrNull(),
      releaseDate: pick('im:releaseDate', 'label').asDateTimeOrNull(),
    );
  }

  const Album({
    required this.link,
    required this.name,
    required this.artist,
    required this.releaseDate,
  });

  @override
  String toString() {
    return 'Album{link: $link, name: $name, artist: $artist, releaseDate: $releaseDate}';
  }
}

Answer 3

这里：

更新模型

class Model {
  Model({
    required this.feed,
  });

  late final Feed feed;

  Model.fromJson(Map<String, dynamic> json) {
    feed = Feed.fromJson(json['feed']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['feed'] = feed.toJson();
    return _data;
  }
}

class Feed {
  Feed({
    required this.author,
    required this.entry,
    required this.updated,
    required this.rights,
    required this.title,
    required this.icon,
    required this.link,
    required this.id,
  });

  late final Author author;
  late final List<Entry> entry;
  late final Updated updated;
  late final Rights rights;
  late final Title title;
  late final Icon icon;
  late final List<Link> link;
  late final Id id;

  Feed.fromJson(Map<String, dynamic> json) {
    author = Author.fromJson(json['author']);
    entry = json['entry'] is Map ? [Entry.fromJson(Map.from(json['entry']))] : List.from(json['entry']).map((e) => Entry.fromJson(Map.from(e))).toList();
    updated = Updated.fromJson(json['updated']);
    rights = Rights.fromJson(json['rights']);
    title = Title.fromJson(json['title']);
    icon = Icon.fromJson(json['icon']);
    link = List.from(json['link']).map((e) => Link.fromJson(e)).toList();
    id = Id.fromJson(json['id']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['author'] = author.toJson();
    _data['entry'] = entry.toString();
    _data['updated'] = updated.toJson();
    _data['rights'] = rights.toJson();
    _data['title'] = title.toJson();
    _data['icon'] = icon.toJson();
    _data['link'] = link.map((e) => e.toJson()).toList();
    _data['id'] = id.toJson();
    return _data;
  }
}

class Author {
  Author({
    required this.name,
    required this.uri,
  });

  late final Name name;
  late final ModelUri uri;

  Author.fromJson(Map<String, dynamic> json) {
    name = Name.fromJson(json['name']);
    uri = ModelUri.fromJson(json['uri']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['name'] = name.toJson();
    _data['uri'] = uri.toJson();
    return _data;
  }
}

class Name {
  Name({
    required this.label,
  });

  late final String label;

  Name.fromJson(Map<String, dynamic> json) {
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    return _data;
  }
}

class ModelUri {
  ModelUri({
    required this.label,
  });

  late final String label;

  ModelUri.fromJson(Map<String, dynamic> json) {
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    return _data;
  }
}

class Entry {
  Entry({
    required this.imname,
    required this.imimage,
    required this.imitemCount,
    required this.imprice,
    required this.imcontentType,
    required this.rights,
    required this.title,
    required this.link,
    required this.id,
    required this.imartist,
    required this.category,
    required this.imreleaseDate,
  });

  late final Imname imname;

  late final List<Imimage> imimage;

  late final ImitemCount imitemCount;

  late final Imprice imprice;

  late final ImcontentType imcontentType;

  late final Rights rights;
  late final Title title;
  late final Link link;
  late final Id id;

  late final Imartist imartist;

  late final Category category;

  late final ImreleaseDate? imreleaseDate;

  Entry.fromJson(Map<String, dynamic> json) {
    imname = Imname.fromJson(json['im:name']);
    imimage =
        List.from(json['im:image']).map((e) => Imimage.fromJson(e)).toList();
    imitemCount = ImitemCount.fromJson(json['im:itemCount']);
    imprice = Imprice.fromJson(json['im:price']);
    imcontentType = ImcontentType.fromJson(json['im:contentType']);
    rights = Rights.fromJson(json['rights']);
    title = Title.fromJson(json['title']);
    link = Link.fromJson(json['link']);
    id = Id.fromJson(json['id']);
    imartist = Imartist.fromJson(json['im:artist']);
    category = Category.fromJson(json['category']);
    imreleaseDate = json['imreleaseDate'] == null
        ? null
        : ImreleaseDate.fromJson(json['imreleaseDate']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['im:name'] = imname.toJson();
    _data['im:image'] = imimage.map((e) => e.toJson()).toList();
    _data['im:itemCount'] = imitemCount.toJson();
    _data['im:price'] = imprice.toJson();
    _data['im:contentType'] = imcontentType.toJson();
    _data['rights'] = rights.toJson();
    _data['title'] = title.toJson();
    _data['link'] = link.toJson();
    _data['id'] = id.toJson();
    _data['im:artist'] = imartist.toJson();
    _data['category'] = category.toJson();
    _data['im:releaseDate'] = imreleaseDate?.toJson();
    return _data;
  }
}

class Imname {
  Imname({
    required this.label,
  });

  late final String label;

  Imname.fromJson(Map<String, dynamic> json) {
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    return _data;
  }
}

class Imimage {
  Imimage({
    required this.label,
    required this.attributes,
  });

  late final String label;
  late final Attributes attributes;

  Imimage.fromJson(Map<String, dynamic> json) {
    label = json['label'];
    attributes = Attributes.fromJson(json['attributes']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    _data['attributes'] = attributes.toJson();
    return _data;
  }
}

class Attributes {
  Attributes({
    required this.height,
  });

  late final String? height;

  Attributes.fromJson(Map<String, dynamic>? json) {
    height = json?['height'];
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['height'] = height;
    return _data;
  }
}

class ImitemCount {
  ImitemCount({
    required this.label,
  });

  late final String label;

  ImitemCount.fromJson(Map<String, dynamic> json) {
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    return _data;
  }
}

class Imprice {
  Imprice({
    required this.label,
    required this.attributes,
  });

  late final String label;
  late final Attributes attributes;

  Imprice.fromJson(Map<String, dynamic> json) {
    label = json['label'];
    attributes = Attributes.fromJson(json['attributes']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    _data['attributes'] = attributes.toJson();
    return _data;
  }
}

class ImcontentType {
  ImcontentType({
    required this.imcontentType,
    required this.attributes,
  });

  late final ImcontentType? imcontentType;
  late final Attributes attributes;

  ImcontentType.fromJson(Map<String, dynamic> json) {

    imcontentType = json['im:contentType'] == null
        ? null
        : ImcontentType.fromJson(json['im:contentType']);
    attributes = Attributes.fromJson(json['attributes']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['im:contentType'] = imcontentType?.toJson();
    _data['attributes'] = attributes.toJson();
    return _data;
  }
}

class Rights {
  Rights({
    required this.label,
  });

  late final String label;

  Rights.fromJson(Map<String, dynamic> json) {
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    return _data;
  }
}

class Title {
  Title({
    required this.label,
  });

  late final String label;

  Title.fromJson(Map<String, dynamic> json) {
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    return _data;
  }
}

class Link {
  Link({
    required this.attributes,
  });

  late final Attributes attributes;

  Link.fromJson(Map<String, dynamic> json) {
    attributes = Attributes.fromJson(json['attributes']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['attributes'] = attributes.toJson();
    return _data;
  }
}

class Id {
  Id({
    required this.label,
    required this.attributes,
  });

  late final String label;
  late final Attributes? attributes;

  Id.fromJson(Map<String, dynamic> json) {
    label = json['label'];
    attributes = json['attributes'] == null
        ? null
        : Attributes.fromJson(json['attributes']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    _data['attributes'] = attributes?.toJson();
    return _data;
  }
}

class Imartist {
  Imartist({
    required this.label,
    required this.attributes,
  });

  late final String label;
  late final Attributes? attributes;

  Imartist.fromJson(Map<String, dynamic> json) {
    print("attribute json: $json");

    label = json['label'];
    attributes =  Attributes.fromJson(json['attributes']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    _data['attributes'] = attributes?.toJson();
    return _data;
  }
}

class Category {
  Category({
    required this.attributes,
  });

  late final Attributes attributes;

  Category.fromJson(Map<String, dynamic> json) {
    attributes = Attributes.fromJson(json['attributes']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['attributes'] = attributes.toJson();
    return _data;
  }
}

class ImreleaseDate {
  ImreleaseDate({
    required this.label,
    required this.attributes,
  });

  late final String label;
  late final Attributes attributes;

  ImreleaseDate.fromJson(Map<String, dynamic> json) {
    label = json['label'];
    attributes = Attributes.fromJson(json['attributes']);
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    _data['attributes'] = attributes.toJson();
    return _data;
  }
}

class Updated {
  Updated({
    required this.label,
  });

  late final String label;

  Updated.fromJson(Map<String, dynamic> json) {
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    return _data;
  }
}

class Icon {
  Icon({
    required this.label,
  });

  late final String label;

  Icon.fromJson(Map<String, dynamic> json) {
    label = json['label'];
  }

  Map<String, dynamic> toJson() {
    final _data = <String, dynamic>{};
    _data['label'] = label;
    return _data;
  }
}

API 调用

main() {
  execute();
}

void execute() async {
  Response response = await get(Uri.parse("https://itunes.apple.com/in/rss/topalbums/limit=1/json"));
  print(response.body);
  var x = Model.fromJson(jsonDecode(response.body));
  print(x.feed.toJson());
}