AsyncRabbitTemplate

AsyncRabbitTemplate.java

/*
 * Copyright 2015 the original author or authors.
 *
 * 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.springframework.amqp.rabbit.core;

import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;

import org.springframework.amqp.AmqpException;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageListener;
import org.springframework.amqp.core.MessagePostProcessor;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;
import org.springframework.context.SmartLifecycle;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.util.concurrent.SettableListenableFuture;

/**
 * @author Gary Russell
 * @since 1.6
 *
 */
public class AsyncRabbitTemplate<T> implements SmartLifecycle, MessageListener {

	private final RabbitTemplate template;

	private final SimpleMessageListenerContainer container;

	private final String queue;

	private final ConcurrentMap<String, RabbitFuture> pending = new ConcurrentHashMap<String, RabbitFuture>();

	private volatile boolean running;

	public AsyncRabbitTemplate(ConnectionFactory connectionFactory, String exchange, String routingKey, String queue) {
		this.template = new RabbitTemplate(connectionFactory);
		this.template.setExchange(exchange);
		this.template.setRoutingKey(routingKey);
		this.container = new SimpleMessageListenerContainer(connectionFactory);
		this.container.setQueueNames(queue);
		this.container.setMessageListener(this);
		this.container.afterPropertiesSet();
		this.queue = queue;
	}

	public AsyncRabbitTemplate(RabbitTemplate template, SimpleMessageListenerContainer container) {
		this.template = template;
		this.container = container;
		this.container.setMessageListener(this);
		this.queue = container.getQueueNames()[0];
	}

	public ListenableFuture<T> convertSendAndReceive(Object data) {
		final String correlationId = UUID.randomUUID().toString();
		this.template.convertAndSend(data, new MessagePostProcessor() {

			@Override
			public Message postProcessMessage(Message message) throws AmqpException {
				message.getMessageProperties().setCorrelationId(correlationId.getBytes());
				message.getMessageProperties().setReplyTo(queue);
				return message;
			}

		});
		RabbitFuture future = new RabbitFuture(correlationId);
		this.pending.put(correlationId, future);
		return future;
	}

	@Override
	public void start() {
		if (!this.running) {
			this.container.start();
		}
		this.running = true;
	}

	@Override
	public void stop() {
		if (this.running) {
			this.container.stop();
		}
		this.running = false;
	}

	@Override
	public boolean isRunning() {
		return this.running;
	}

	@Override
	public int getPhase() {
		return 0;
	}

	@Override
	public boolean isAutoStartup() {
		return true;
	}

	@Override
	public void stop(Runnable callback) {
		stop();
		callback.run();
	}



	@Override
	public void onMessage(Message message) {
		String correlationId = new String(message.getMessageProperties().getCorrelationId());
		if (correlationId != null) {
			RabbitFuture future = this.pending.remove(correlationId);
			if (future != null) {
				@SuppressWarnings("unchecked")
				T converted = (T) this.template.getMessageConverter().fromMessage(message);
				future.set(converted);
			}
		}
	}

	public class RabbitFuture extends SettableListenableFuture<T> {

		private final String correlationId;

		public RabbitFuture(String correlationId) {
			this.correlationId = correlationId;
		}

		@Override
		public boolean cancel(boolean mayInterruptIfRunning) {
			boolean cancelled = super.cancel(mayInterruptIfRunning);
			pending.remove(this.correlationId);
			return cancelled;
		}

	}

}

AsyncRabbitTemplateTests.java

/*
 * Copyright 2015 the original author or authors.
 *
 * 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.springframework.amqp.rabbit.core;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

import java.util.Map;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;

import org.junit.Test;
import org.junit.runner.RunWith;

import org.springframework.amqp.core.AnonymousQueue;
import org.springframework.amqp.core.Queue;
import org.springframework.amqp.rabbit.connection.CachingConnectionFactory;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;
import org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter;
import org.springframework.amqp.utils.test.TestUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.util.concurrent.ListenableFutureCallback;

/**
 * @author Gary Russell
 * @since 1.6
 *
 */
@ContextConfiguration
@RunWith(SpringJUnit4ClassRunner.class)
public class AsyncRabbitTemplateTests {

	@Autowired
	private AsyncRabbitTemplate<String> template;

	@Test
	public void testOK() throws Exception {
		ListenableFuture<String> future = this.template.convertSendAndReceive("foo");
		final CountDownLatch latch = new CountDownLatch(1);
		final AtomicReference<String> resultRef = new AtomicReference<String>();
		future.addCallback(new ListenableFutureCallback<String>() {

			@Override
			public void onSuccess(String result) {
				resultRef.set(result);
				latch.countDown();
			}

			@Override
			public void onFailure(Throwable ex) {
				latch.countDown();
			}

		});
		assertTrue(latch.await(10, TimeUnit.SECONDS));
		assertEquals("FOO", resultRef.get());
	}

	@Test
	public void testCancel() throws Exception {
		ListenableFuture<String> future = this.template.convertSendAndReceive("foo");
		future.cancel(false);
		assertEquals(0, TestUtils.getPropertyValue(template, "pending", Map.class).size());
	}

	@Configuration
	public static class Config {

		@Bean
		public ConnectionFactory connectionFactory() {
			return new CachingConnectionFactory("localhost");
		}

		@Bean
		public Queue requests() {
			return new AnonymousQueue();
		}

		@Bean
		public Queue replies() {
			return new AnonymousQueue();
		}

		@Bean
		public RabbitAdmin admin(ConnectionFactory connectionFactory) {
			return new RabbitAdmin(connectionFactory);
		}

		@Bean
		public RabbitTemplate template(ConnectionFactory connectionFactory) {
			RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
			rabbitTemplate.setRoutingKey(requests().getName());
			return rabbitTemplate;
		}

		@Bean
		@Primary
		public SimpleMessageListenerContainer replyContainer(ConnectionFactory connectionFactory) {
			SimpleMessageListenerContainer container = new SimpleMessageListenerContainer(connectionFactory);
			container.setQueueNames(replies().getName());
			return container;
		}

		@Bean
		public AsyncRabbitTemplate<String> asyncTemplate(RabbitTemplate template,
				SimpleMessageListenerContainer container) {
			return new AsyncRabbitTemplate<String>(template, container);
		}

		@Bean
		public SimpleMessageListenerContainer remoteContainer(ConnectionFactory connectionFactory) {
			SimpleMessageListenerContainer container = new SimpleMessageListenerContainer(connectionFactory);
			container.setQueueNames(requests().getName());
			container.setMessageListener(new MessageListenerAdapter(new Object() {

				@SuppressWarnings("unused")
				public String handleMessage(String message) {
					return message.toUpperCase();
				}

			}));
			return container;
		}

	}

}