Object Encoder/Decoder UserDao PersonDao EventDao AuthTokenDao … Object Encoder/Decoder Encodes objects in JSON format Decodes objects from JSON format Data Access DB register RegisterResult register(RegisterRequest r) Register Handler Register Service Main server class Server login LoginResult login(LoginRequest r) Login Handler Login Service User table Person table Event table AuthToken table … ClearResult clear() Clear Handler clear Clear Service Model User Person Event AuthToken … Fill Handler fill FillResult fill(FillRequest r) Fill Service Web … … Class that client app will use to call methods on the server Server Proxy RegisterResult register(RegisterRequest r) LoginResult login(LoginRequest r) ClearResult clear() FillResult fill(FillRequest r) …