Java tutorial
/* * Copyright 2016 Pivotal Software, Inc.. * * 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. */ package io.github.proxyprint.kitchen.utils; import com.google.common.collect.HashMultimap; import com.google.common.collect.Multimap; import io.github.proxyprint.kitchen.WebAppConfig; import io.github.proxyprint.kitchen.models.consumer.Consumer; import io.github.proxyprint.kitchen.models.notifications.Notification; import io.github.proxyprint.kitchen.models.repositories.ConsumerDAO; import io.github.proxyprint.kitchen.models.repositories.NotificationDAO; import java.io.IOException; import java.util.logging.Level; import org.apache.catalina.connector.ClientAbortException; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.MediaType; import org.springframework.web.servlet.mvc.method.annotation.SseEmitter; /** * * @author jose */ public class NotificationManager { private final Logger logger = LoggerFactory.getLogger(WebAppConfig.class); @Autowired private ConsumerDAO consumers; @Autowired private NotificationDAO notifications; private final Multimap<String, SseEmitter> subscriptions; public NotificationManager() { this.subscriptions = HashMultimap.create(); } public SseEmitter subscribe(String username) { SseEmitter sseEmitter = new SseEmitter(0l); sseEmitter.onCompletion(new DeleteTask(this, username, sseEmitter)); this.subscriptions.put(username, sseEmitter); return sseEmitter; } public void unsubscribe(String username, SseEmitter emitter) { this.subscriptions.remove(username, emitter); } public void sendNotification(String username, Notification notification) { Consumer consumer = this.consumers.findByUsername(username); notification = notifications.save(notification); consumer.addNotifications(notification); consumers.save(consumer); if (this.subscriptions.containsKey(username)) { for (SseEmitter sse : this.subscriptions.get(username)) { try { sse.send(notification, MediaType.APPLICATION_JSON); } catch (IOException ex) { this.logger.warn("Broken SSE Emitter..discarding it..."); } } } } public void removeNotification(long notificationId) { notifications.delete(notificationId); } public void readNotification(long notificationId) { Notification n = notifications.findById(notificationId); n.setReadStatus(true); notifications.save(n); } } class DeleteTask implements Runnable { private final Logger logger = LoggerFactory.getLogger(WebAppConfig.class); private NotificationManager notifications; private String username; private SseEmitter sse; public DeleteTask(NotificationManager notifications, String username, SseEmitter sse) { this.notifications = notifications; this.username = username; this.sse = sse; } @Override public void run() { this.logger.info(username + " disconnected!"); this.notifications.unsubscribe(username, sse); } }