This is my first flutter tutorial, which explain how you can host and read json data from GitHub repository.

First up all you need to host json in GitHub Page , here is the complete guide. After that you can read the data using http package in Flutter.

First up all you need to specify the pubspec.yml settings as follows

dependencies:
  flutter:
    sdk: flutter
  http: ^0.12.0+2

Go to your pubspec file and add the high lighted sections to use the network/web connection.

Now we need a Model class to read and hold the json object. Eventually the fetchpost Future will extract the data from GitHub.

Future<Post> fetchPost() async {
  final response = await http.get('https://jdata-server.github.io/data.json');
  if (response.statusCode == 200) {
    // If server returns an OK response, parse the JSON
    return Post.fromJson(json.decode(response.body));
  } else {
    // If that response was not OK, throw an error.
    throw Exception('Failed to load post');
  }
}

A special function called FutureBuilder help us to feched post object.Here is the complete main.dart file

import 'package:flutter/material.dart';
import 'dart:convert';
import 'package:http/http.dart' as http;
import 'dart:async';
Future<Post> fetchPost() async {
  final response = await http.get('https://jdata-server.github.io/data.json');
  if (response.statusCode == 200) {
    // If server returns an OK response, parse the JSON
    return Post.fromJson(json.decode(response.body));
  } else {
    // If that response was not OK, throw an error.
    throw Exception('Failed to load post');
  }
}
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}
class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);
  final String title;
  @override
  _MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
  Future<Post> post;
  void initState() {
    super.initState();
    post = fetchPost();
  }
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
          child: FutureBuilder<Post>(
        future: post,
        builder: (context, snapshot) {
          if (snapshot.hasData) {
            return new ListView(children: <Widget>[
              new Text("Q:" + snapshot.data.question),
              new Text("A:" + snapshot.data.answer)
            ]);
          } else if (snapshot.hasError) {
            return Text("${snapshot.error}");
          }
          // By default, show a loading spinner
          return CircularProgressIndicator();
        },
      )),
      floatingActionButton: FloatingActionButton(
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

class Post {
  final String question;
  final String answer;
  final String catagory;
  Post({this.question, this.answer, this.catagory});
  factory Post.fromJson(Map<String, dynamic> json) {
    return Post(
        question: json['question'],
        answer: json['answer'],
        catagory: json['catagory']);
  }
}