Java tutorial
package com.devicehive.util; /* * #%L * DeviceHive Java Server Common business logic * %% * Copyright (C) 2016 DataArt * %% * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * #L% */ import com.devicehive.configuration.Constants; import com.devicehive.configuration.Messages; import com.devicehive.exceptions.HiveException; import com.devicehive.json.GsonFactory; import com.devicehive.json.strategies.JsonPolicyDef; import com.devicehive.model.DeviceCommand; import com.devicehive.model.DeviceNotification; import com.devicehive.model.JsonStringWrapper; import com.devicehive.vo.DeviceEquipmentVO; import com.devicehive.vo.DeviceVO; import com.google.gson.Gson; import com.google.gson.JsonElement; import com.google.gson.JsonObject; import org.springframework.util.Assert; import javax.servlet.http.HttpServletResponse; import java.util.Random; import static com.devicehive.json.strategies.JsonPolicyDef.Policy.*; public class ServerResponsesFactory { public static JsonObject createNotificationInsertMessage(DeviceNotification deviceNotification, String subId) { JsonElement deviceNotificationJson = GsonFactory.createGson(NOTIFICATION_TO_CLIENT) .toJsonTree(deviceNotification); JsonObject resultMessage = new JsonObject(); resultMessage.addProperty("action", "notification/insert"); resultMessage.addProperty(Constants.DEVICE_GUID, deviceNotification.getDeviceGuid()); resultMessage.add(Constants.NOTIFICATION, deviceNotificationJson); resultMessage.addProperty(Constants.SUBSCRIPTION_ID, subId); return resultMessage; } public static JsonObject createCommandInsertMessage(DeviceCommand deviceCommand, String subId) { JsonElement deviceCommandJson = GsonFactory.createGson(COMMAND_TO_DEVICE).toJsonTree(deviceCommand, DeviceCommand.class); JsonObject resultJsonObject = new JsonObject(); resultJsonObject.addProperty("action", "command/insert"); resultJsonObject.addProperty(Constants.DEVICE_GUID, deviceCommand.getDeviceGuid()); resultJsonObject.add(Constants.COMMAND, deviceCommandJson); resultJsonObject.addProperty(Constants.SUBSCRIPTION_ID, subId); return resultJsonObject; } public static JsonObject createCommandUpdateMessage(DeviceCommand deviceCommand) { JsonElement deviceCommandJson = GsonFactory.createGson(COMMAND_UPDATE_TO_CLIENT).toJsonTree(deviceCommand); JsonObject resultJsonObject = new JsonObject(); resultJsonObject.addProperty("action", "command/update"); resultJsonObject.add(Constants.COMMAND, deviceCommandJson); return resultJsonObject; } public static String parseNotificationStatus(DeviceNotification notificationMessage) { Assert.notNull(notificationMessage.getParameters(), "Notification parameters are required."); String jsonParametersString = notificationMessage.getParameters().getJsonString(); Gson gson = GsonFactory.createGson(); JsonElement parametersJsonElement = gson.fromJson(jsonParametersString, JsonElement.class); JsonObject statusJsonObject; if (parametersJsonElement instanceof JsonObject) { statusJsonObject = (JsonObject) parametersJsonElement; } else { throw new HiveException(Messages.PARAMS_NOT_JSON, HttpServletResponse.SC_BAD_REQUEST); } JsonElement jsonElement = statusJsonObject.get(Constants.STATUS); Assert.notNull(jsonElement, "Parameter " + Constants.STATUS + " is required."); return jsonElement.getAsString(); } public static DeviceNotification createNotificationForDevice(DeviceVO device, String notificationName) { DeviceNotification notification = new DeviceNotification(); notification.setId(Math.abs(new Random().nextInt())); // TODO: remove this when id generation will be moved to backend notification.setNotification(notificationName); notification.setDeviceGuid(device.getGuid()); Gson gson = GsonFactory.createGson(JsonPolicyDef.Policy.DEVICE_PUBLISHED); JsonElement deviceAsJson = gson.toJsonTree(device); JsonStringWrapper wrapperOverDevice = new JsonStringWrapper(deviceAsJson.toString()); notification.setParameters(wrapperOverDevice); return notification; } public static DeviceEquipmentVO parseDeviceEquipmentNotification(DeviceNotification notification, DeviceVO device) { final String notificationParameters = notification.getParameters().getJsonString(); if (notificationParameters == null) { throw new HiveException(Messages.NO_NOTIFICATION_PARAMS, HttpServletResponse.SC_BAD_REQUEST); } Gson gson = GsonFactory.createGson(); JsonElement parametersJsonElement = gson.fromJson(notificationParameters, JsonElement.class); JsonObject jsonEquipmentObject; if (parametersJsonElement instanceof JsonObject) { jsonEquipmentObject = (JsonObject) parametersJsonElement; } else { throw new HiveException(Messages.PARAMS_NOT_JSON, HttpServletResponse.SC_BAD_REQUEST); } return constructDeviceEquipmentObject(jsonEquipmentObject, device); } private static DeviceEquipmentVO constructDeviceEquipmentObject(JsonObject jsonEquipmentObject, DeviceVO device) { DeviceEquipmentVO result = new DeviceEquipmentVO(); final JsonElement jsonElement = jsonEquipmentObject.get(Constants.EQUIPMENT); if (jsonElement == null) { throw new HiveException(Messages.NO_EQUIPMENT_IN_JSON, HttpServletResponse.SC_BAD_REQUEST); } String deviceEquipmentCode = jsonElement.getAsString(); result.setCode(deviceEquipmentCode); jsonEquipmentObject.remove(Constants.EQUIPMENT); result.setParameters(new JsonStringWrapper(jsonEquipmentObject.toString())); return result; } }