我有一個非常復雜的 JSON 檔案來決議：
{
"adult": false,
"backdrop_url": "https://image.tmdb.org/t/p/w500/gLbBRyS7MBrmVUNce91Hmx9vzqI.jpg",
"belongs_to_collection": {
"id": 230,
"name": "The Godfather Collection",
"poster_url": "https://image.tmdb.org/t/p/w200/sSbkKCHtIEakht5rnEjrWeR2LLG.jpg",
"backdrop_url": "https://image.tmdb.org/t/p/w500/3WZTxpgscsmoUk81TuECXdFOD0R.jpg"
},
"budget": 13000000,
"genres": [
"Drama",
"Crime"
],
"homepage": null,
"id": 240,
"imdb_id": "tt0071562",
"original_language": "en",
"original_title": "The Godfather: Part II",
"overview": "In the continuing saga of the Corleone crime family, a young Vito Corleone grows up in Sicily and in 1910s New York. In the 1950s, Michael Corleone attempts to expand the family business into Las Vegas, Hollywood and Cuba.",
"popularity": 17.578,
"poster_url": "https://image.tmdb.org/t/p/w200/bVq65huQ8vHDd1a4Z37QtuyEvpA.jpg",
"production_companies": [
{
"id": 4,
"logo_url": "https://image.tmdb.org/t/p/w200/fycMZt242LVjagMByZOLUGbCvv3.png",
"name": "Paramount",
"origin_country": "US"
},
{
"id": 536,
"logo_url": null,
"name": "The Coppola Company",
"origin_country": ""
}
],
"production_countries": [
{
"iso_3166_1": "US",
"name": "United States of America"
}
],
"release_date": "1974-12-20",
"revenue": 102600000,
"runtime": 200,
"spoken_languages": [
{
"iso_639_1": "en",
"name": "English"
},
{
"iso_639_1": "it",
"name": "Italiano"
},
{
"iso_639_1": "la",
"name": "Latin"
},
{
"iso_639_1": "es",
"name": "Espa?ol"
}
],
"status": "Released",
"tagline": "I don't feel I have to wipe everybody out, Tom. Just my enemies.",
"title": "The Godfather: Part II",
"video": false,
"vote_average": 8.5,
"vote_count": 4794
}
這是我的決議類：
class movieDetails {
bool? adult;
String? backdropUrl;
Null? belongsToCollection;
int? budget;
List<String>? genres;
Null? homepage;
int? id;
String? imdbId;
String? originalLanguage;
String? originalTitle;
String? overview;
double? popularity;
String? posterUrl;
List<ProductionCompanies>? productionCompanies;
List<ProductionCountries>? productionCountries;
String? releaseDate;
int? revenue;
int? runtime;
List<SpokenLanguages>? spokenLanguages;
String? status;
String? tagline;
String? title;
bool? video;
double? voteAverage;
int? voteCount;
movieDetails(
{this.adult,
this.backdropUrl,
this.belongsToCollection,
this.budget,
this.genres,
this.homepage,
this.id,
this.imdbId,
this.originalLanguage,
this.originalTitle,
this.overview,
this.popularity,
this.posterUrl,
this.productionCompanies,
this.productionCountries,
this.releaseDate,
this.revenue,
this.runtime,
this.spokenLanguages,
this.status,
this.tagline,
this.title,
this.video,
this.voteAverage,
this.voteCount});
movieDetails.fromJson(Map<String, dynamic> json) {
adult = json['adult'];
backdropUrl = json['backdrop_url'];
belongsToCollection = json['belongs_to_collection'];
budget = json['budget'];
genres = json['genres'].cast<String>();
homepage = json['homepage'];
id = json['id'];
imdbId = json['imdb_id'];
originalLanguage = json['original_language'];
originalTitle = json['original_title'];
overview = json['overview'];
popularity = json['popularity'];
posterUrl = json['poster_url'];
if (json['production_companies'] != null) {
productionCompanies = <ProductionCompanies>[];
json['production_companies'].forEach((v) {
productionCompanies!.add(new ProductionCompanies.fromJson(v));
});
}
if (json['production_countries'] != null) {
productionCountries = <ProductionCountries>[];
json['production_countries'].forEach((v) {
productionCountries!.add(new ProductionCountries.fromJson(v));
});
}
releaseDate = json['release_date'];
revenue = json['revenue'];
runtime = json['runtime'];
if (json['spoken_languages'] != null) {
spokenLanguages = <SpokenLanguages>[];
json['spoken_languages'].forEach((v) {
spokenLanguages!.add(new SpokenLanguages.fromJson(v));
});
}
status = json['status'];
tagline = json['tagline'];
title = json['title'];
video = json['video'];
voteAverage = json['vote_average'];
voteCount = json['vote_count'];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['adult'] = this.adult;
data['backdrop_url'] = this.backdropUrl;
data['belongs_to_collection'] = this.belongsToCollection;
data['budget'] = this.budget;
data['genres'] = this.genres;
data['homepage'] = this.homepage;
data['id'] = this.id;
data['imdb_id'] = this.imdbId;
data['original_language'] = this.originalLanguage;
data['original_title'] = this.originalTitle;
data['overview'] = this.overview;
data['popularity'] = this.popularity;
data['poster_url'] = this.posterUrl;
if (this.productionCompanies != null) {
data['production_companies'] =
this.productionCompanies!.map((v) => v.toJson()).toList();
}
if (this.productionCountries != null) {
data['production_countries'] =
this.productionCountries!.map((v) => v.toJson()).toList();
}
data['release_date'] = this.releaseDate;
data['revenue'] = this.revenue;
data['runtime'] = this.runtime;
if (this.spokenLanguages != null) {
data['spoken_languages'] =
this.spokenLanguages!.map((v) => v.toJson()).toList();
}
data['status'] = this.status;
data['tagline'] = this.tagline;
data['title'] = this.title;
data['video'] = this.video;
data['vote_average'] = this.voteAverage;
data['vote_count'] = this.voteCount;
return data;
}
}
class ProductionCompanies {
int? id;
String? logoUrl;
String? name;
String? originCountry;
ProductionCompanies({this.id, this.logoUrl, this.name, this.originCountry});
ProductionCompanies.fromJson(Map<String, dynamic> json) {
id = json['id'];
logoUrl = json['logo_url'];
name = json['name'];
originCountry = json['origin_country'];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['id'] = this.id;
data['logo_url'] = this.logoUrl;
data['name'] = this.name;
data['origin_country'] = this.originCountry;
return data;
}
}
class ProductionCountries {
String? iso31661;
String? name;
ProductionCountries({this.iso31661, this.name});
ProductionCountries.fromJson(Map<String, dynamic> json) {
iso31661 = json['iso_3166_1'];
name = json['name'];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['iso_3166_1'] = this.iso31661;
data['name'] = this.name;
return data;
}
}
class SpokenLanguages {
String? iso6391;
String? name;
SpokenLanguages({this.iso6391, this.name});
SpokenLanguages.fromJson(Map<String, dynamic> json) {
iso6391 = json['iso_639_1'];
name = json['name'];
}
Map<String, dynamic> toJson() {
final Map<String, dynamic> data = new Map<String, dynamic>();
data['iso_639_1'] = this.iso6391;
data['name'] = this.name;
return data;
}
}
由于我是從互聯網上獲取這個 JSON 的，所以這里是獲取方法：
Future<movieDetails> fetchDetails() async {
final response = await http.get(Uri.parse(url)); //url: just a string containing the website's URL
if (response.statusCode == 200){
return compute(parseDetails, response.body);
}
else{
throw Exception('Failed!');
}
}
從這里看起來一切都很好，但是我真的不知道如何執行該parseDetails功能。我該怎么做？這個 JSON 檔案太復雜了，我無法處理。
uj5u.com熱心網友回復：
您是否有任何理由使用計算來決議 JSON 檔案？您提供的檔案似乎具有合理的長度，并且不會阻塞主要隔離（除非檔案比您提供的檔案大得多，計算可能合適）
您的代碼將是這樣的（將決議主隔離中的 JSON 回應）。有關更多詳細資訊，請參閱有關 JSON 的官方檔案。還有一個提示，遵循 dart 命名約定 PascalCase 類（MovieDetails 而不是 movieDetails）
Future<movieDetails> fetchDetails() async {
final response = await http.get(Uri.parse(url)); //url: just a string containing the website's URL
if (response.statusCode == 200){
Map<String, dynamic> movieDetailsMap = jsonDecode(response.body);
return movieDetails.fromJson(movieDetailsMap);
}
else{
throw Exception('Failed!');
}
}
uj5u.com熱心網友回復：
movieDetails parseDetails(String responseBody) {
final parsed = jsonDecode(responseBody).cast<Map<String, dynamic>>();
return movieDetails.fromJson(parsed);
}
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