Java tutorial
/* * Copyright 2015 herd contributors * * 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 org.finra.herd.service.advice; import java.lang.reflect.Method; import org.aspectj.lang.ProceedingJoinPoint; import org.aspectj.lang.annotation.Around; import org.aspectj.lang.annotation.Aspect; import org.aspectj.lang.reflect.MethodSignature; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Component; import org.finra.herd.model.annotation.PublishNotificationMessages; import org.finra.herd.model.dto.NotificationMessage; import org.finra.herd.service.NotificationMessagePublishingService; import org.finra.herd.service.helper.NotificationMessageInMemoryQueue; /** * Advice that publishes notification messages stored in the "in-memory" notification message queue. */ @Component @Aspect public class PublishNotificationMessagesAdvice extends AbstractServiceAdvice { private static final Logger LOGGER = LoggerFactory.getLogger(PublishNotificationMessagesAdvice.class); @Autowired private NotificationMessageInMemoryQueue notificationMessageInMemoryQueue; @Autowired private NotificationMessagePublishingService notificationMessagePublishingService; /** * Publishes all notification messages stored in the "in-memory" notification message queue. * * @param joinPoint the join point * * @return the return value of the method at the join point * @throws Throwable if any errors were encountered */ @Around("serviceMethods()") public Object publishNotificationMessages(ProceedingJoinPoint joinPoint) throws Throwable { MethodSignature methodSignature = (MethodSignature) joinPoint.getSignature(); Method method = methodSignature.getMethod(); boolean publishNotificationMessages = method.isAnnotationPresent(PublishNotificationMessages.class); // Proceed to the join point (i.e. call the method and let it return). try { Object returnValue = joinPoint.proceed(); if (publishNotificationMessages) { if (LOGGER.isDebugEnabled()) { // Get the target class being called. Class<?> targetClass = joinPoint.getTarget().getClass(); LOGGER.debug( "Method is initiating notification message publishing. javaMethod=\"{}.{}\" notificationMessageInMemoryQueueSize={}", targetClass.getName(), methodSignature.getName(), notificationMessageInMemoryQueue.size()); } // Publish all notification messages stored in the "in-memory" notification message queue. while (!notificationMessageInMemoryQueue.isEmpty()) { // Get notification message from the "in-memory" queue. NotificationMessage notificationMessage = notificationMessageInMemoryQueue.remove(); // Publish the message. try { notificationMessagePublishingService.publishNotificationMessage(notificationMessage); } catch (Exception sqsException) { // On error, add this notification message to the database queue. try { notificationMessagePublishingService .addNotificationMessageToDatabaseQueue(notificationMessage); } catch (Exception dbException) { // Log the error. LOGGER.error( "Failed to add notification message to the database queue. messageType=\"{}\" messageDestination=\"{}\" messageText={}", notificationMessage.getMessageType(), notificationMessage.getMessageDestination(), notificationMessage.getMessageText(), dbException); } } } } return returnValue; } finally { // Removes all of the elements from the queue, since the thread might be reused from the thread pool. if (publishNotificationMessages) { notificationMessageInMemoryQueue.clear(); } } } }