persistence.dart

import 'package:flutter/material.dart';
import 'package:hive/hive.dart';

void main() async {
  Hive..init(Directory.current.path);
  await HiveDB.openBox('my_db');

  HiveDB.saveItem(item: 'Chizi', key: 'Name');

  print(await HiveDB.getItem('Name')); //returns Chizi
}

abstract class HiveDB {
  static var boxName = '';

  static Future<Box<dynamic>> openBox(_) async {
    boxName = _;
    return await Hive.openBox(boxName);
  }

  static saveItem({@required item, @required key}) async {
    var box = Hive.box(boxName);
    box.put(key, item);
  }

  static eraseItem({@required key}) async {
    var box = Hive.box(boxName);
    box.delete(key);
  }

  static eraseItems({List<String> keys}) async {
    var box = await Hive.openBox(boxName);
    box.deleteAll(keys);
  }

  static eraseAll() async {
    await Hive.deleteFromDisk();
  }

  static getItem(key) async {
    var box = Hive.box(boxName);
    return box.get(key);
  }
}