using System;

using System.Collections.Generic;

using Newtonsoft.Json;

​

public class Program

{

    public static void Main()

    {

        var database = new MyDatabase

        {

            Books = new List<Book>(),

            Users = new List<User>() { new User { Login = "admin", Password = "admin" } },

            Registry = new List<Registry>()

        };

        var json = JsonConvert.SerializeObject(database);

        var newDb = JsonConvert.DeserializeObject<MyDatabase>(json);

        Console.WriteLine("Login from deserialized database: " + newDb.Users[0].Login);

    }

}

​

public class MyDatabase

{

    public List<Book> Books { get; set; }

    public List<User> Users { get; set; }

    public List<Registry> Registry { get; set; }

}

​

public class Book { }

​

public class User

{

    public string Login { get; set; }

    public string Password { get; set; }

}

​

public class Registry { }