ExecutorChannelTests.java example

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spring-integration-master
/*
 * Copyright 2002-2016 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.integration.channel;

import static org.hamcrest.Matchers.equalTo;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
import static org.mockito.BDDMockito.willThrow;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;

import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

import org.junit.Test;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.core.task.SimpleAsyncTaskExecutor;
import org.springframework.core.task.SyncTaskExecutor;
import org.springframework.integration.dispatcher.RoundRobinLoadBalancingStrategy;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageDeliveryException;
import org.springframework.messaging.MessageHandler;
import org.springframework.messaging.support.ChannelInterceptorAdapter;
import org.springframework.messaging.support.ExecutorChannelInterceptor;
import org.springframework.messaging.support.GenericMessage;
import org.springframework.scheduling.concurrent.ConcurrentTaskExecutor;
import org.springframework.scheduling.concurrent.CustomizableThreadFactory;

/**
 * @author Mark Fisher
 * @author Artem Bilan
 */
public class ExecutorChannelTests {

	@Test
	public void verifyDifferentThread() throws Exception {
		SimpleAsyncTaskExecutor taskExecutor = new SimpleAsyncTaskExecutor();
		taskExecutor.setThreadNamePrefix("test-");
		ExecutorChannel channel = new ExecutorChannel(taskExecutor);
		CountDownLatch latch = new CountDownLatch(1);
		TestHandler handler = new TestHandler(latch);
		channel.subscribe(handler);
		channel.send(new GenericMessage<String>("test"));
		latch.await(1000, TimeUnit.MILLISECONDS);
		assertEquals(0, latch.getCount());
		assertNotNull(handler.thread);
		assertFalse(Thread.currentThread().equals(handler.thread));
		assertEquals("test-1", handler.thread.getName());
	}

	@Test
	public void roundRobinLoadBalancing() throws Exception {
		int numberOfMessages = 11;
		ConcurrentTaskExecutor taskExecutor = new ConcurrentTaskExecutor(
				Executors.newSingleThreadScheduledExecutor(new CustomizableThreadFactory("test-")));
		ExecutorChannel channel = new ExecutorChannel(
				taskExecutor, new RoundRobinLoadBalancingStrategy());
		CountDownLatch latch = new CountDownLatch(numberOfMessages);
		TestHandler handler1 = new TestHandler(latch);
		TestHandler handler2 = new TestHandler(latch);
		TestHandler handler3 = new TestHandler(latch);
		channel.subscribe(handler1);
		channel.subscribe(handler2);
		channel.subscribe(handler3);
		for (int i = 0; i < numberOfMessages; i++) {
			channel.send(new GenericMessage<String>("test-" + i));
		}
		latch.await(3000, TimeUnit.MILLISECONDS);
		assertEquals(0, latch.getCount());
		assertNotNull(handler1.thread);
		assertFalse(Thread.currentThread().equals(handler1.thread));
		assertTrue(handler1.thread.getName().startsWith("test-"));
		assertNotNull(handler2.thread);
		assertFalse(Thread.currentThread().equals(handler2.thread));
		assertTrue(handler2.thread.getName().startsWith("test-"));
		assertNotNull(handler3.thread);
		assertFalse(Thread.currentThread().equals(handler3.thread));
		assertTrue(handler3.thread.getName().startsWith("test-"));
		assertEquals(4, handler1.count.get());
		assertEquals(4, handler2.count.get());
		assertEquals(3, handler3.count.get());
	}

	@Test
	public void verifyFailoverWithLoadBalancing() throws Exception {
		int numberOfMessages = 11;
		ConcurrentTaskExecutor taskExecutor = new ConcurrentTaskExecutor(
				Executors.newSingleThreadScheduledExecutor(new CustomizableThreadFactory("test-")));
		ExecutorChannel channel = new ExecutorChannel(
				taskExecutor, new RoundRobinLoadBalancingStrategy());
		CountDownLatch latch = new CountDownLatch(numberOfMessages);
		TestHandler handler1 = new TestHandler(latch);
		TestHandler handler2 = new TestHandler(latch);
		TestHandler handler3 = new TestHandler(latch);
		channel.subscribe(handler1);
		channel.subscribe(handler2);
		channel.subscribe(handler3);
		handler2.shouldFail = true;
		for (int i = 0; i < numberOfMessages; i++) {
			channel.send(new GenericMessage<String>("test-" + i));
		}
		latch.await(3000, TimeUnit.MILLISECONDS);
		assertEquals(0, latch.getCount());
		assertNotNull(handler1.thread);
		assertFalse(Thread.currentThread().equals(handler1.thread));
		assertTrue(handler1.thread.getName().startsWith("test-"));
		assertNotNull(handler2.thread);
		assertFalse(Thread.currentThread().equals(handler2.thread));
		assertTrue(handler2.thread.getName().startsWith("test-"));
		assertNotNull(handler3.thread);
		assertFalse(Thread.currentThread().equals(handler3.thread));
		assertTrue(handler3.thread.getName().startsWith("test-"));
		assertEquals(0, handler2.count.get());
		assertEquals(4, handler1.count.get());
		assertEquals(7, handler3.count.get());
	}

	@Test
	public void verifyFailoverWithoutLoadBalancing() throws Exception {
		int numberOfMessages = 11;
		ConcurrentTaskExecutor taskExecutor = new ConcurrentTaskExecutor(
				Executors.newSingleThreadScheduledExecutor(new CustomizableThreadFactory("test-")));
		ExecutorChannel channel = new ExecutorChannel(taskExecutor, null);
		CountDownLatch latch = new CountDownLatch(numberOfMessages);
		TestHandler handler1 = new TestHandler(latch);
		TestHandler handler2 = new TestHandler(latch);
		TestHandler handler3 = new TestHandler(latch);
		channel.subscribe(handler1);
		channel.subscribe(handler2);
		channel.subscribe(handler3);
		handler1.shouldFail = true;
		for (int i = 0; i < numberOfMessages; i++) {
			channel.send(new GenericMessage<String>("test-" + i));
		}
		latch.await(3000, TimeUnit.MILLISECONDS);
		assertEquals(0, latch.getCount());
		assertNotNull(handler1.thread);
		assertFalse(Thread.currentThread().equals(handler1.thread));
		assertTrue(handler1.thread.getName().startsWith("test-"));
		assertNotNull(handler2.thread);
		assertFalse(Thread.currentThread().equals(handler2.thread));
		assertTrue(handler2.thread.getName().startsWith("test-"));
		assertNull(handler3.thread);
		assertEquals(0, handler1.count.get());
		assertEquals(0, handler3.count.get());
		assertEquals(numberOfMessages, handler2.count.get());
	}

	@Test
	public void interceptorWithModifiedMessage() {
		ExecutorChannel channel = new ExecutorChannel(new SyncTaskExecutor());
		channel.setBeanFactory(mock(BeanFactory.class));
		channel.afterPropertiesSet();

		MessageHandler handler = mock(MessageHandler.class);
		Message<?> expected = mock(Message.class);
		BeforeHandleInterceptor interceptor = new BeforeHandleInterceptor();
		interceptor.setMessageToReturn(expected);
		channel.addInterceptor(interceptor);
		channel.subscribe(handler);
		channel.send(new GenericMessage<Object>("foo"));
		verify(handler).handleMessage(expected);
		assertEquals(1, interceptor.getCounter().get());
		assertTrue(interceptor.wasAfterHandledInvoked());
	}

	@Test
	public void interceptorWithException() {
		ExecutorChannel channel = new ExecutorChannel(new SyncTaskExecutor());
		channel.setBeanFactory(mock(BeanFactory.class));
		channel.afterPropertiesSet();

		Message<Object> message = new GenericMessage<Object>("foo");

		MessageHandler handler = mock(MessageHandler.class);
		IllegalStateException expected = new IllegalStateException("Fake exception");
		willThrow(expected).given(handler).handleMessage(message);
		BeforeHandleInterceptor interceptor = new BeforeHandleInterceptor();
		channel.addInterceptor(interceptor);
		channel.subscribe(handler);
		try {
			channel.send(message);
		}
		catch (MessageDeliveryException actual) {
			assertSame(expected, actual.getCause());
		}
		verify(handler).handleMessage(message);
		assertEquals(1, interceptor.getCounter().get());
		assertTrue(interceptor.wasAfterHandledInvoked());
	}

	@Test
	public void testEarlySubscribe() {
		ExecutorChannel channel = new ExecutorChannel(mock(Executor.class));
		try {
			channel.subscribe(m -> { });
			channel.setBeanFactory(mock(BeanFactory.class));
			channel.afterPropertiesSet();
			fail("expected Exception");
		}
		catch (IllegalStateException e) {
			assertThat(e.getMessage(), equalTo("You cannot subscribe() until the channel "
					+ "bean is fully initialized by the framework. Do not subscribe in a @Bean definition"));
		}
	}


	private static class TestHandler implements MessageHandler {

		private final CountDownLatch latch;

		private final AtomicInteger count = new AtomicInteger();

		private volatile Thread thread;

		private volatile boolean shouldFail;

		TestHandler(CountDownLatch latch) {
			this.latch = latch;
		}

		@Override
		public void handleMessage(Message<?> message) {
			this.thread = Thread.currentThread();
			if (this.shouldFail) {
				throw new RuntimeException("intentional test failure");
			}
			this.count.incrementAndGet();
			this.latch.countDown();
		}
	}

	private static class BeforeHandleInterceptor extends ChannelInterceptorAdapter
			implements ExecutorChannelInterceptor {

		private final AtomicInteger counter = new AtomicInteger();

		private volatile boolean afterHandledInvoked;

		private Message<?> messageToReturn;

		BeforeHandleInterceptor() {
			super();
		}

		public void setMessageToReturn(Message<?> messageToReturn) {
			this.messageToReturn = messageToReturn;
		}

		public AtomicInteger getCounter() {
			return this.counter;
		}

		public boolean wasAfterHandledInvoked() {
			return this.afterHandledInvoked;
		}

		@Override
		public Message<?> beforeHandle(Message<?> message, MessageChannel channel, MessageHandler handler) {
			assertNotNull(message);
			this.counter.incrementAndGet();
			return (this.messageToReturn != null ? this.messageToReturn : message);
		}

		@Override
		public void afterMessageHandled(Message<?> message, MessageChannel channel, MessageHandler handler,
										Exception ex) {
			this.afterHandledInvoked = true;
		}

	}

}