Convert JSON into POJO (Object) similar to android in Flutter

Android Studio plugin: https://plugins.jetbrains.com/plugin/12562-jsontodart-json-to-dart-

Online: https://javiercbk.github.io/json_to_dart/

Manually parse: https://medium.com/flutter-community/parsing-complex-json-in-flutter-747c46655f51

Generate Dart classes from JSON

Convert JSON to Dart class

Generate Dart class from JSON or JSON-Schema.

json_serializable isn't that well documented, but it does exactly what you want, is easier to use and requires less boilerplate than built_value, especially when it comes to arrays.

import 'package:json_annotation/json_annotation.dart';
import 'dart:convert';

part 'school.g.dart';

@JsonSerializable()
class School {
  final String name;

  final int maxStudentCount;

  final List<Student> students;

  School(this.name, this.maxStudentCount, this.students);
  factory School.fromJson(Map<String, dynamic> json) => _$SchoolFromJson(json);
  Map<String, dynamic> toJson() => _$SchoolToJson(this);
}

@JsonSerializable()
class Student {
  final String name;

  final DateTime birthDate;

  Student({this.name, this.birthDate});
  factory Student.fromJson(Map<String, dynamic> json) => _$StudentFromJson(json);
  Map<String, dynamic> toJson() => _$StudentToJson(this);
}

test() {
  String jsonString = '''{
   "name":"Trump University",
   "maxStudentCount":9999,
   "students":[
      {
         "name":"Peter Parker",
         "birthDate":"1999-01-01T00:00:00.000Z"
      }
   ]
  }''';

  final decodedJson = json.decode(jsonString);

  final school = School.fromJson(decodedJson);

  assert(school.students.length == 1);
}

It also supports enum serialization.

To generate the serialization code, run:

flutter packages pub run build_runner build