Unexpected end of input (at character 1)

Question

I have json file with the following data in it:

{
  "item1": "value1",
  "item2": "value2",
  "item3": "value3"
}

I also have Items() class in a seperate file which has the method getItems() method which loads the json file:

class Items {
  Future<Map<String, dynamic>> getItems() async {
    String jsonData =
        await rootBundle.loadString('assets/items.json');
    Map<String, dynamic> data = jsonDecode(jsonData);
    return data;
  }
}

I also have a scaffold to show the items with ListView.builder. I first use setState to assign the returned value of Items().getItems() to the field items. I then use the value of the field inside the LisView.builder

class ItemList extends StatefulWidget {
  const ItemList({Key? key}) : super(key: key);

  @override
  _ItemListState createState() => _ItemListState();
}

class _ItemListState extends State<ItemList> {
  late String items = '';
  setItems() async {
    final item = await Items().getItems();
    setState(() {
      items = jsonEncode(item);
    });
  }

  @override
  initState() {
    setItems();
  }

  @override
  Widget build(BuildContext context) {
    Map<String, dynamic> data = jsonDecode(items);
    debugPrint(data.toString());
    debugPrint(items);

    return Scaffold(
      body: ListView.builder(
        itemCount: data.keys.length,
        itemBuilder: (c, index) {
          return ListTile(
            title: Text("key " + data.keys.toList()[index]),
            subtitle: Text("value " + data.values.toList()[index]),
          );
        },
      ),
    );
  }
}

I am able to show the list of items on the Scaffold() but i still get the error: Unexpected end of input (at character 1)

When i click on the error it highlights on the jsonDecode(items). So something goes wrong there but i don't know what.