AMQP-796: Fix Admin Transaction

JIRA: https://jira.spring.io/browse/AMQP-796

If an admin uses a transactional `RabbitTemplate` it will start a transaction.
If the connection was opened due to a `RabbitTemplate` operation it should participate
in the same transaction.
Previously, the template used a second channel and treated it as a local transaction.

Also fix the `RabbitAdmin` so it does no work if there is nothing to declare.

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/connection/ConnectionFactoryUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -155,6 +155,18 @@ private static RabbitResourceHolder doGetTransactionalResourceHolder(ConnectionF
 			channel = ConsumerChannelRegistry.getConsumerChannel(connectionFactory);
 			if (channel == null && connection == null) {
 				connection = resourceFactory.createConnection();
+				if (resourceHolder == null) {
+					/*
+					 * While creating a connection, a connection listener might have created a
+					 * transactional channel and bound it to the transaction.
+					 */
+					resourceHolder = (RabbitResourceHolder) TransactionSynchronizationManager
+							.getResource(connectionFactory);
+					if (resourceHolder != null) {
+						channel = resourceHolder.getChannel();
+						resourceHolderToUse = resourceHolder;
+					}
+				}
 				resourceHolderToUse.addConnection(connection);
 			}
 			if (channel == null) {

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/core/RabbitAdmin.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -475,6 +475,10 @@ else if (declarable instanceof Binding) {
 			}
 		}
 
+		if (exchanges.size() == 0 && queues.size() == 0 && bindings.size() == 0) {
+			this.logger.debug("Nothing to declare");
+			return;
+		}
 		this.rabbitTemplate.execute(channel -> {
 			declareExchanges(channel, exchanges.toArray(new Exchange[exchanges.size()]));
 			declareQueues(channel, queues.toArray(new Queue[queues.size()]));

spring-rabbit/src/test/java/org/springframework/amqp/rabbit/core/RabbitAdminDeclarationTests.java

@@ -24,8 +24,11 @@
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyMap;
+import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.eq;
 import static org.mockito.ArgumentMatchers.isNull;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.BDDMockito.willReturn;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.never;
@@ -55,6 +58,7 @@
 import org.springframework.amqp.rabbit.connection.Connection;
 import org.springframework.amqp.rabbit.connection.ConnectionFactory;
 import org.springframework.amqp.rabbit.connection.ConnectionListener;
+import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -313,6 +317,26 @@ public void testAddRemove() {
 		}
 	}
 
+	@Test
+	public void testNoOpWhenNothingToDeclare() throws Exception {
+		com.rabbitmq.client.ConnectionFactory cf = mock(com.rabbitmq.client.ConnectionFactory.class);
+		com.rabbitmq.client.Connection connection = mock(com.rabbitmq.client.Connection.class);
+		Channel channel = mock(Channel.class, "channel1");
+		given(channel.isOpen()).willReturn(true);
+		willReturn(connection).given(cf).newConnection(any(ExecutorService.class), anyString());
+		given(connection.isOpen()).willReturn(true);
+		given(connection.createChannel()).willReturn(channel);
+		CachingConnectionFactory ccf = new CachingConnectionFactory(cf);
+		ccf.setExecutor(mock(ExecutorService.class));
+		RabbitTemplate rabbitTemplate = new RabbitTemplate(ccf);
+		RabbitAdmin admin = new RabbitAdmin(rabbitTemplate);
+		ApplicationContext ac = mock(ApplicationContext.class);
+		admin.setApplicationContext(ac);
+		admin.afterPropertiesSet();
+		ccf.createConnection();
+		verify(connection, never()).createChannel();
+	}
+
 	@Configuration
 	public static class Config {
 

spring-rabbit/src/test/java/org/springframework/amqp/rabbit/core/RabbitAdminTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.

spring-rabbit/src/test/java/org/springframework/amqp/rabbit/core/RabbitTemplateTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -17,6 +17,7 @@
 package org.springframework.amqp.rabbit.core;
 
 import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.equalTo;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertThat;
@@ -25,13 +26,16 @@
 import static org.mockito.ArgumentMatchers.anyBoolean;
 import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.ArgumentMatchers.isNull;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.BDDMockito.willReturn;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 import static org.mockito.Mockito.withSettings;
 
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.ExecutorService;
@@ -48,15 +52,18 @@
 import org.springframework.amqp.core.Address;
 import org.springframework.amqp.core.Message;
 import org.springframework.amqp.core.MessageProperties;
+import org.springframework.amqp.core.Queue;
 import org.springframework.amqp.core.ReceiveAndReplyCallback;
 import org.springframework.amqp.rabbit.connection.AbstractRoutingConnectionFactory;
 import org.springframework.amqp.rabbit.connection.CachingConnectionFactory;
+import org.springframework.amqp.rabbit.connection.ChannelProxy;
 import org.springframework.amqp.rabbit.connection.PublisherCallbackChannelConnectionFactory;
 import org.springframework.amqp.rabbit.connection.SimpleRoutingConnectionFactory;
 import org.springframework.amqp.rabbit.connection.SingleConnectionFactory;
 import org.springframework.amqp.rabbit.support.PublisherCallbackChannel;
 import org.springframework.amqp.support.converter.SimpleMessageConverter;
 import org.springframework.amqp.utils.SerializationUtils;
+import org.springframework.context.ApplicationContext;
 import org.springframework.expression.Expression;
 import org.springframework.expression.spel.standard.SpelExpressionParser;
 import org.springframework.retry.support.RetryTemplate;
@@ -74,6 +81,7 @@
 import com.rabbitmq.client.Consumer;
 import com.rabbitmq.client.Envelope;
 import com.rabbitmq.client.impl.AMQImpl;
+import com.rabbitmq.client.impl.AMQImpl.Queue.DeclareOk;
 
 /**
  * @author Gary Russell
@@ -327,4 +335,65 @@ public void testRoutingConnectionFactory() throws Exception {
 		Mockito.verify(connectionFactory2, Mockito.times(4)).createConnection();
 	}
 
+	@Test
+	public void testNestedTxBinding() throws Exception {
+		ConnectionFactory cf = mock(ConnectionFactory.class);
+		Connection connection = mock(Connection.class);
+		Channel channel1 = mock(Channel.class, "channel1");
+		given(channel1.isOpen()).willReturn(true);
+		Channel channel2 = mock(Channel.class, "channel2");
+		given(channel2.isOpen()).willReturn(true);
+		willReturn(connection).given(cf).newConnection(any(ExecutorService.class), anyString());
+		given(connection.isOpen()).willReturn(true);
+		given(connection.createChannel()).willReturn(channel1, channel2);
+		DeclareOk dok = new DeclareOk("foo", 0, 0);
+		willReturn(dok).given(channel1).queueDeclare(anyString(), anyBoolean(), anyBoolean(), anyBoolean(), isNull());
+		CachingConnectionFactory ccf = new CachingConnectionFactory(cf);
+		ccf.setExecutor(mock(ExecutorService.class));
+		RabbitTemplate rabbitTemplate = new RabbitTemplate(ccf);
+		rabbitTemplate.setChannelTransacted(true);
+		RabbitAdmin admin = new RabbitAdmin(rabbitTemplate);
+		ApplicationContext ac = mock(ApplicationContext.class);
+		willReturn(Collections.singletonMap("foo", new Queue("foo"))).given(ac).getBeansOfType(Queue.class);
+		admin.setApplicationContext(ac);
+		admin.afterPropertiesSet();
+		AtomicReference<Channel> templateChannel = new AtomicReference<>();
+		new TransactionTemplate(new TestTransactionManager()).execute(s -> {
+			return rabbitTemplate.execute(c -> {
+				templateChannel.set(c);
+				return true;
+			});
+		});
+		verify(channel1).txSelect();
+		verify(channel1).queueDeclare(anyString(), anyBoolean(), anyBoolean(), anyBoolean(), isNull());
+		assertThat(((ChannelProxy) templateChannel.get()).getTargetChannel(), equalTo(channel1));
+		verify(channel1).txCommit();
+	}
+
+	@SuppressWarnings("serial")
+	private class TestTransactionManager extends AbstractPlatformTransactionManager {
+
+		TestTransactionManager() {
+			super();
+		}
+
+		@Override
+		protected void doBegin(Object transaction, TransactionDefinition definition) throws TransactionException {
+		}
+
+		@Override
+		protected void doCommit(DefaultTransactionStatus status) throws TransactionException {
+		}
+
+		@Override
+		protected Object doGetTransaction() throws TransactionException {
+			return new Object();
+		}
+
+		@Override
+		protected void doRollback(DefaultTransactionStatus status) throws TransactionException {
+		}
+
+	}
+
 }