Java tutorial
package com.devicehive.handler.command; /* * #%L * DeviceHive Backend 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.eventbus.EventBus; import com.devicehive.model.eventbus.Subscriber; import com.devicehive.model.eventbus.Subscription; import com.devicehive.model.rpc.Action; import com.devicehive.model.rpc.CommandUnsubscribeRequest; import com.devicehive.model.rpc.CommandUnsubscribeResponse; import com.devicehive.shim.api.Request; import com.devicehive.shim.api.Response; import com.devicehive.shim.api.server.RequestHandler; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.util.Assert; import java.util.HashSet; import java.util.Set; public class CommandUnsubscribeRequestHandler implements RequestHandler { @Autowired private EventBus eventBus; @Override public Response handle(Request request) { CommandUnsubscribeRequest body = (CommandUnsubscribeRequest) request.getBody(); validate(body); if (body.getSubscriptionId() != null) { Subscriber subscriber = new Subscriber(body.getSubscriptionId(), request.getReplyTo(), request.getCorrelationId()); eventBus.unsubscribe(subscriber); CommandUnsubscribeResponse unsubscribeResponse = new CommandUnsubscribeResponse( body.getSubscriptionId(), null); return Response.newBuilder().withBody(unsubscribeResponse).withLast(false) .withCorrelationId(request.getCorrelationId()).buildSuccess(); } else if (body.getDeviceGuids() != null) { Set<Subscription> subscriptions = new HashSet<>(); Set<Subscriber> subscribers = new HashSet<>(); for (String name : body.getDeviceGuids()) { Subscription subscription = new Subscription(Action.COMMAND_EVENT.name(), name); subscriptions.add(subscription); } subscriptions.forEach(subscription -> subscribers.addAll(eventBus.getSubscribers(subscription))); subscribers.forEach(subscriber -> eventBus.unsubscribe(subscriber)); CommandUnsubscribeResponse unsubscribeResponse = new CommandUnsubscribeResponse(null, body.getDeviceGuids()); return Response.newBuilder().withBody(unsubscribeResponse).withLast(false) .withCorrelationId(request.getCorrelationId()).buildSuccess(); } else { throw new IllegalArgumentException("Both subscription id and device guids are null"); } } private void validate(CommandUnsubscribeRequest request) { Assert.notNull(request, "Request body is null"); } }