Java tutorial
/** * The MIT License (MIT) * * Copyright (c) 2011-2016 Incapture Technologies LLC * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ package rapture.exchange.rabbitmq; import java.io.IOException; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import org.apache.log4j.Logger; import rapture.common.RapturePipelineTask; import rapture.common.exception.ExceptionToString; import rapture.common.impl.jackson.JacksonUtil; import rapture.exchange.QueueHandler; import com.google.common.util.concurrent.ThreadFactoryBuilder; import com.rabbitmq.client.AMQP; import com.rabbitmq.client.Channel; import com.rabbitmq.client.DefaultConsumer; import com.rabbitmq.client.Envelope; import rapture.config.MultiValueConfigLoader; public class MessageConsumer extends DefaultConsumer { private static Logger log = Logger.getLogger(MessageConsumer.class); private QueueHandler handler; private String tag; private ExecutorService service; public MessageConsumer(Channel channel, String tag, QueueHandler handler, String queueName) { super(channel); this.tag = tag; this.handler = handler; String threadPoolSizeString = MultiValueConfigLoader.getConfig("RUNNER-rabbitMQConsumerPoolSize", "50"); int threadPoolSize = Integer.parseInt(threadPoolSizeString); service = Executors.newFixedThreadPool(threadPoolSize, new ThreadFactoryBuilder().setNameFormat("MessageConsumer-" + queueName + "-%d").build()); } @Override public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) { final String routingKey = envelope.getRoutingKey(); final String contentType = properties.getContentType(); final long deliveryTag = envelope.getDeliveryTag(); log.debug(String.format(Messages.getString("RabbitExchangeHandler.receivedMessage"), deliveryTag)); //$NON-NLS-1$ final RapturePipelineTask task = JacksonUtil.objectFromJson(new String(body), RapturePipelineTask.class); log.debug(Messages.getString("RabbitExchangeHandler.PlacingTask")); //$NON-NLS-1$ try { service.execute(new Runnable() { @Override public void run() { boolean ret; try { ret = handler.handleMessage(tag, routingKey, contentType, task); log.debug( String.format(Messages.getString("RabbitExchangeHandler.acknowledgeMessage"), ret)); //$NON-NLS-1$ } catch (Exception e) { log.error(String.format(Messages.getString("RabbitExchangeHandler.noAcknowledge"), ExceptionToString.format(e))); } finally { try { getChannel().basicAck(deliveryTag, false); } catch (IOException e) { log.error(String.format("Error while acknowledging message with tag '%s':\n%s", deliveryTag, ExceptionToString.format(e))); } } log.debug(Messages.getString("RabbitExchangeHandler.deliveryHandled")); //$NON-NLS-1$ } }); } catch (Exception e) { e.printStackTrace(); } } }