Java tutorial
/* * * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you 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.apache.airavata.messaging.core.impl; import com.rabbitmq.client.*; import org.apache.airavata.common.utils.ThriftUtils; import org.apache.airavata.messaging.core.MessageContext; import org.apache.airavata.messaging.core.MessageHandler; import org.apache.airavata.model.dbevent.DBEventMessage; import org.apache.airavata.model.dbevent.DBEventMessageContext; import org.apache.airavata.model.messaging.event.ExperimentSubmitEvent; import org.apache.airavata.model.messaging.event.Message; import org.apache.log4j.LogManager; import org.apache.log4j.Logger; import org.apache.thrift.TBase; import org.apache.thrift.TException; import java.io.IOException; public class MessageConsumer extends QueueingConsumer { private static final Logger logger = LogManager.getLogger(MessageConsumer.class); private MessageHandler handler; private Channel channel; private Connection connection; public MessageConsumer(MessageHandler messageHandler, Connection connection, Channel channel) { super(channel); this.handler = messageHandler; this.connection = connection; this.channel = channel; } @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { Message message = new Message(); try { logger.info("handleDelivery() -> Handling message delivery. Consumer Tag : " + consumerTag); ThriftUtils.createThriftFromBytes(body, message); DBEventMessage dBEventMessage = new DBEventMessage(); ThriftUtils.createThriftFromBytes(message.getEvent(), dBEventMessage); MessageContext messageContext = new MessageContext((TBase) dBEventMessage, message.getMessageType(), message.getMessageId(), "gatewayId", envelope.getDeliveryTag()); handler.onMessage(messageContext); //sendAck(deliveryTag); } catch (TException e) { logger.error("handleDelivery() -> Error handling delivery. Consumer Tag : " + consumerTag, e); } } private void sendAck(long deliveryTag) { logger.info("sendAck() -> Sending ack. Delivery Tag : " + deliveryTag); try { if (channel.isOpen()) { channel.basicAck(deliveryTag, false); } else { channel = connection.createChannel(); channel.basicQos(20); channel.basicAck(deliveryTag, false); } } catch (IOException e) { logger.error("sendAck() -> Error sending ack. Delivery Tag : " + deliveryTag, e); } } }