Device

Just like with Google Home devices and Amazon Alexa devices, SUSI.AI Users should have a way to add and store the information of their devices (Smart Speakers) on SUSI Server, so that it could be displayed to them on various clients. Hence, we needed a Servlet which could add and store the User data on the Server. Implementation of Servlets in SUSI.AI All servlets in SUSI extend AbstractAPIHandler class and implement APIHandler. All servlets have 4 methods, which we overwrite depending on what we want the servlet to do. They are as follows : @Override public String getAPIPath() { return null; } @Override public BaseUserRole getMinimalBaseUserRole() { return null; } @Override public JSONObject getDefaultPermissions(BaseUserRole baseUserRole) { return null; } @Override public ServiceResponse serviceImpl(Query post, HttpServletResponse response, Authorization rights, JsonObjectWithDefault permissions) throws APIException { Return null; }   How these 4 methods work together? First method is getAPIPath(). It returns the endpoint of the servlet. The second method is getMinimalBaseUserRole(). It returns the minimum privilege level required to access the endpoint. The third method is getDefaultPermissions(). It gets the Default Permissions of a UserRole in SUSI Server. Different UserRoles have different permissions defined in SUSI Server. Whenever the endpoint defined in the getAPIPath() method is called properly, it responds with whatever is defined in the fourth method, which is serviceImpl(). How is User data stored on SUSI Server? Before we move on to the actual implementation of the API required to store the device information, we should get a brief idea of how exactly User data is stored on SUSI Server. Every SUSI User has an Accounting Object. It is a JSONObject which stores the Settings of the particular User on the Server. For example, every time you change some setting on the Web Client https://chat.susi.ai, an API call is made to aaa/changeUserSettings.json with appropriate parameters with information of the changed setting, and the User settings are stored to the Server in the Accounting Object of the User. Implementation of a Servlet to store Device information on Server The task of this servlet is to store the information of a new device (Smart speaker) whenever it is initially set up using the Android/iOS app. This is the implementation of the 4 methods of a servlet which is used to store information of connected devices: @Override public String getAPIPath() { return "/aaa/addNewDevice.json"; } @Override public UserRole getMinimalUserRole() { return UserRole.USER; } @Override public JSONObject getDefaultPermissions(UserRole baseUserRole) { return null; } @Override public ServiceResponse serviceImpl(Query query, HttpServletResponse response, Authorization authorization, JsonObjectWithDefault permissions) throws APIException { JSONObject value = new JSONObject(); String key = query.get("macid", null); String name = query.get("name", null); String device = query.get("device", null); if (key == null || name == null || device == null) { throw new APIException(400, "Bad service call, missing arguments"); } else { value.put(name, device); } if (authorization.getIdentity() == null) { throw new APIException(400, "Specified user data not found, ensure you are logged in"); } else { Accounting accounting = DAO.getAccounting(authorization.getIdentity()); if (accounting.getJSON().has("devices")) { accounting.getJSON().getJSONObject("devices").put(key, value); }…