Allow to customize the RabbitMQ RetryTemplate

This commit adds the ability to customize the RetryTemplate used in the
RabbitMQ infrastructure. The customizer is slightly unusual and offer
a `Target` enum that define the component that will use the retry
template: `SENDER` for the auto-configured `RabbitTemplate` and
`LISTENER` for a listener container created by a
`RabbitListenerContainerFactoryConfigurer`.

Closes gh-13793

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/amqp/AbstractRabbitListenerContainerFactoryConfigurer.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure.amqp;
 
+import java.util.List;
+
 import org.springframework.amqp.rabbit.config.AbstractRabbitListenerContainerFactory;
 import org.springframework.amqp.rabbit.config.RetryInterceptorBuilder;
 import org.springframework.amqp.rabbit.connection.ConnectionFactory;
@@ -40,6 +42,8 @@ public abstract class AbstractRabbitListenerContainerFactoryConfigurer<T extends
 
 	private MessageRecoverer messageRecoverer;
 
+	private List<RabbitRetryTemplateCustomizer> retryTemplateCustomizers;
+
 	private RabbitProperties rabbitProperties;
 
 	/**
@@ -59,6 +63,15 @@ public abstract class AbstractRabbitListenerContainerFactoryConfigurer<T extends
 		this.messageRecoverer = messageRecoverer;
 	}
 
+	/**
+	 * Set the {@link RabbitRetryTemplateCustomizer} instances to use.
+	 * @param retryTemplateCustomizers the retry template customizers
+	 */
+	protected void setRetryTemplateCustomizers(
+			List<RabbitRetryTemplateCustomizer> retryTemplateCustomizers) {
+		this.retryTemplateCustomizers = retryTemplateCustomizers;
+	}
+
 	/**
 	 * Set the {@link RabbitProperties} to use.
 	 * @param rabbitProperties the {@link RabbitProperties}
@@ -108,7 +121,9 @@ public abstract class AbstractRabbitListenerContainerFactoryConfigurer<T extends
 					? RetryInterceptorBuilder.stateless()
 					: RetryInterceptorBuilder.stateful());
 			builder.retryOperations(
-					new RetryTemplateFactory().createRetryTemplate(retryConfig));
+					new RetryTemplateFactory(this.retryTemplateCustomizers)
+							.createRetryTemplate(retryConfig,
+									RabbitRetryTemplateCustomizer.Target.LISTENER));
 			MessageRecoverer recoverer = (this.messageRecoverer != null
 					? this.messageRecoverer : new RejectAndDontRequeueRecoverer());
 			builder.recoverer(recoverer);

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/amqp/RabbitAnnotationDrivenConfiguration.java

@@ -16,6 +16,8 @@
 
 package org.springframework.boot.autoconfigure.amqp;
 
+import java.util.List;
+
 import org.springframework.amqp.rabbit.annotation.EnableRabbit;
 import org.springframework.amqp.rabbit.config.DirectRabbitListenerContainerFactory;
 import org.springframework.amqp.rabbit.config.RabbitListenerConfigUtils;
@@ -45,13 +47,17 @@ class RabbitAnnotationDrivenConfiguration {
 
 	private final ObjectProvider<MessageRecoverer> messageRecoverer;
 
+	private final ObjectProvider<List<RabbitRetryTemplateCustomizer>> retryTemplateCustomizers;
+
 	private final RabbitProperties properties;
 
 	RabbitAnnotationDrivenConfiguration(ObjectProvider<MessageConverter> messageConverter,
 			ObjectProvider<MessageRecoverer> messageRecoverer,
+			ObjectProvider<List<RabbitRetryTemplateCustomizer>> retryTemplateCustomizers,
 			RabbitProperties properties) {
 		this.messageConverter = messageConverter;
 		this.messageRecoverer = messageRecoverer;
+		this.retryTemplateCustomizers = retryTemplateCustomizers;
 		this.properties = properties;
 	}
 
@@ -61,6 +67,8 @@ class RabbitAnnotationDrivenConfiguration {
 		SimpleRabbitListenerContainerFactoryConfigurer configurer = new SimpleRabbitListenerContainerFactoryConfigurer();
 		configurer.setMessageConverter(this.messageConverter.getIfUnique());
 		configurer.setMessageRecoverer(this.messageRecoverer.getIfUnique());
+		configurer.setRetryTemplateCustomizers(
+				this.retryTemplateCustomizers.getIfAvailable());
 		configurer.setRabbitProperties(this.properties);
 		return configurer;
 	}
@@ -82,6 +90,8 @@ class RabbitAnnotationDrivenConfiguration {
 		DirectRabbitListenerContainerFactoryConfigurer configurer = new DirectRabbitListenerContainerFactoryConfigurer();
 		configurer.setMessageConverter(this.messageConverter.getIfUnique());
 		configurer.setMessageRecoverer(this.messageRecoverer.getIfUnique());
+		configurer.setRetryTemplateCustomizers(
+				this.retryTemplateCustomizers.getIfAvailable());
 		configurer.setRabbitProperties(this.properties);
 		return configurer;
 	}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/amqp/RabbitAutoConfiguration.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.amqp;
 
 import java.time.Duration;
+import java.util.List;
 
 import com.rabbitmq.client.Channel;
 
@@ -151,15 +152,18 @@ public class RabbitAutoConfiguration {
 	@Import(RabbitConnectionFactoryCreator.class)
 	protected static class RabbitTemplateConfiguration {
 
+		private final RabbitProperties properties;
+
 		private final ObjectProvider<MessageConverter> messageConverter;
 
-		private final RabbitProperties properties;
+		private final ObjectProvider<List<RabbitRetryTemplateCustomizer>> retryTemplateCustomizers;
 
-		public RabbitTemplateConfiguration(
+		public RabbitTemplateConfiguration(RabbitProperties properties,
 				ObjectProvider<MessageConverter> messageConverter,
-				RabbitProperties properties) {
-			this.messageConverter = messageConverter;
+				ObjectProvider<List<RabbitRetryTemplateCustomizer>> retryTemplateCustomizers) {
 			this.properties = properties;
+			this.messageConverter = messageConverter;
+			this.retryTemplateCustomizers = retryTemplateCustomizers;
 		}
 
 		@Bean
@@ -175,8 +179,10 @@ public class RabbitAutoConfiguration {
 			template.setMandatory(determineMandatoryFlag());
 			RabbitProperties.Template properties = this.properties.getTemplate();
 			if (properties.getRetry().isEnabled()) {
-				template.setRetryTemplate(new RetryTemplateFactory()
-						.createRetryTemplate(properties.getRetry()));
+				template.setRetryTemplate(new RetryTemplateFactory(
+						this.retryTemplateCustomizers.getIfAvailable())
+								.createRetryTemplate(properties.getRetry(),
+										RabbitRetryTemplateCustomizer.Target.SENDER));
 			}
 			map.from(properties::getReceiveTimeout).whenNonNull().as(Duration::toMillis)
 					.to(template::setReceiveTimeout);

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/amqp/RabbitRetryTemplateCustomizer.java

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2012-2018 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.
+ * 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.boot.autoconfigure.amqp;
+
+import org.springframework.amqp.rabbit.core.RabbitTemplate;
+import org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer;
+import org.springframework.retry.support.RetryTemplate;
+
+/**
+ * Callback interface that can be used to customize a {@link RetryTemplate} used as part
+ * of the Rabbit infrastructure.
+ *
+ * @author Stephane Nicoll
+ * @since 2.1.0
+ */
+@FunctionalInterface
+public interface RabbitRetryTemplateCustomizer {
+
+	/**
+	 * Callback to customize a {@link RetryTemplate} instance used in the context of the
+	 * specified {@link Target}.
+	 * @param target the {@link Target} of the retry template
+	 * @param retryTemplate the template to customize
+	 */
+	void customize(Target target, RetryTemplate retryTemplate);
+
+	/**
+	 * Define the available target for a {@link RetryTemplate}.
+	 */
+	enum Target {
+
+		/**
+		 * {@link RabbitTemplate} target.
+		 */
+		SENDER,
+
+		/**
+		 * {@link AbstractMessageListenerContainer} target.
+		 */
+		LISTENER
+
+	}
+
+}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/amqp/RetryTemplateFactory.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.amqp;
 
 import java.time.Duration;
+import java.util.List;
 
 import org.springframework.boot.context.properties.PropertyMapper;
 import org.springframework.retry.backoff.ExponentialBackOffPolicy;
@@ -31,7 +32,14 @@ import org.springframework.retry.support.RetryTemplate;
  */
 class RetryTemplateFactory {
 
-	public RetryTemplate createRetryTemplate(RabbitProperties.Retry properties) {
+	private final List<RabbitRetryTemplateCustomizer> customizers;
+
+	RetryTemplateFactory(List<RabbitRetryTemplateCustomizer> customizers) {
+		this.customizers = customizers;
+	}
+
+	public RetryTemplate createRetryTemplate(RabbitProperties.Retry properties,
+			RabbitRetryTemplateCustomizer.Target target) {
 		PropertyMapper map = PropertyMapper.get();
 		RetryTemplate template = new RetryTemplate();
 		SimpleRetryPolicy policy = new SimpleRetryPolicy();
@@ -44,6 +52,11 @@ class RetryTemplateFactory {
 		map.from(properties::getMaxInterval).whenNonNull().as(Duration::toMillis)
 				.to(backOffPolicy::setMaxInterval);
 		template.setBackOffPolicy(backOffPolicy);
+		if (this.customizers != null) {
+			for (RabbitRetryTemplateCustomizer customizer : this.customizers) {
+				customizer.customize(target, template);
+			}
+		}
 		return template;
 	}
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/amqp/RabbitAutoConfigurationTests.java

@@ -32,6 +32,7 @@ import org.springframework.amqp.core.AcknowledgeMode;
 import org.springframework.amqp.core.AmqpAdmin;
 import org.springframework.amqp.core.Message;
 import org.springframework.amqp.rabbit.annotation.EnableRabbit;
+import org.springframework.amqp.rabbit.config.AbstractRabbitListenerContainerFactory;
 import org.springframework.amqp.rabbit.config.DirectRabbitListenerContainerFactory;
 import org.springframework.amqp.rabbit.config.RabbitListenerConfigUtils;
 import org.springframework.amqp.rabbit.config.SimpleRabbitListenerContainerFactory;
@@ -54,8 +55,11 @@ import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Primary;
+import org.springframework.retry.RetryPolicy;
+import org.springframework.retry.backoff.BackOffPolicy;
 import org.springframework.retry.backoff.ExponentialBackOffPolicy;
 import org.springframework.retry.interceptor.MethodInvocationRecoverer;
+import org.springframework.retry.policy.NeverRetryPolicy;
 import org.springframework.retry.policy.SimpleRetryPolicy;
 import org.springframework.retry.support.RetryTemplate;
 
@@ -280,6 +284,28 @@ public class RabbitAutoConfigurationTests {
 				});
 	}
 
+	@Test
+	public void testRabbitTemplateRetryWithCustomizer() {
+		this.contextRunner
+				.withUserConfiguration(RabbitRetryTemplateCustomizerConfiguration.class)
+				.withPropertyValues("spring.rabbitmq.template.retry.enabled:true",
+						"spring.rabbitmq.template.retry.initialInterval:2000")
+				.run((context) -> {
+					RabbitTemplate rabbitTemplate = context.getBean(RabbitTemplate.class);
+					DirectFieldAccessor dfa = new DirectFieldAccessor(rabbitTemplate);
+					RetryTemplate retryTemplate = (RetryTemplate) dfa
+							.getPropertyValue("retryTemplate");
+					assertThat(retryTemplate).isNotNull();
+					dfa = new DirectFieldAccessor(retryTemplate);
+					assertThat(dfa.getPropertyValue("backOffPolicy"))
+							.isSameAs(context.getBean(
+									RabbitRetryTemplateCustomizerConfiguration.class).backOffPolicy);
+					ExponentialBackOffPolicy backOffPolicy = (ExponentialBackOffPolicy) dfa
+							.getPropertyValue("backOffPolicy");
+					assertThat(backOffPolicy.getInitialInterval()).isEqualTo(100);
+				});
+	}
+
 	@Test
 	public void testRabbitTemplateExchangeAndRoutingKey() {
 		this.contextRunner.withUserConfiguration(TestConfiguration.class)
@@ -470,6 +496,53 @@ public class RabbitAutoConfigurationTests {
 				});
 	}
 
+	@Test
+	public void testSimpleRabbitListenerContainerFactoryRetryWithCustomizer() {
+		this.contextRunner
+				.withUserConfiguration(RabbitRetryTemplateCustomizerConfiguration.class)
+				.withPropertyValues("spring.rabbitmq.listener.simple.retry.enabled:true",
+						"spring.rabbitmq.listener.simple.retry.maxAttempts:4")
+				.run((context) -> {
+					SimpleRabbitListenerContainerFactory rabbitListenerContainerFactory = context
+							.getBean("rabbitListenerContainerFactory",
+									SimpleRabbitListenerContainerFactory.class);
+					assertListenerRetryTemplate(rabbitListenerContainerFactory,
+							context.getBean(
+									RabbitRetryTemplateCustomizerConfiguration.class).retryPolicy);
+				});
+	}
+
+	@Test
+	public void testDirectRabbitListenerContainerFactoryRetryWithCustomizer() {
+		this.contextRunner
+				.withUserConfiguration(RabbitRetryTemplateCustomizerConfiguration.class)
+				.withPropertyValues("spring.rabbitmq.listener.type:direct",
+						"spring.rabbitmq.listener.direct.retry.enabled:true",
+						"spring.rabbitmq.listener.direct.retry.maxAttempts:4")
+				.run((context) -> {
+					DirectRabbitListenerContainerFactory rabbitListenerContainerFactory = context
+							.getBean("rabbitListenerContainerFactory",
+									DirectRabbitListenerContainerFactory.class);
+					assertListenerRetryTemplate(rabbitListenerContainerFactory,
+							context.getBean(
+									RabbitRetryTemplateCustomizerConfiguration.class).retryPolicy);
+				});
+	}
+
+	private void assertListenerRetryTemplate(
+			AbstractRabbitListenerContainerFactory<?> rabbitListenerContainerFactory,
+			RetryPolicy retryPolicy) {
+		DirectFieldAccessor dfa = new DirectFieldAccessor(rabbitListenerContainerFactory);
+		Advice[] adviceChain = (Advice[]) dfa.getPropertyValue("adviceChain");
+		assertThat(adviceChain).isNotNull();
+		assertThat(adviceChain.length).isEqualTo(1);
+		dfa = new DirectFieldAccessor(adviceChain[0]);
+		RetryTemplate retryTemplate = (RetryTemplate) dfa
+				.getPropertyValue("retryOperations");
+		dfa = new DirectFieldAccessor(retryTemplate);
+		assertThat(dfa.getPropertyValue("retryPolicy")).isSameAs(retryPolicy);
+	}
+
 	@Test
 	public void testRabbitListenerContainerFactoryConfigurersAreAvailable() {
 		this.contextRunner.withUserConfiguration(TestConfiguration.class)
@@ -793,6 +866,33 @@ public class RabbitAutoConfigurationTests {
 
 	}
 
+	@Configuration
+	protected static class RabbitRetryTemplateCustomizerConfiguration {
+
+		private final BackOffPolicy backOffPolicy = new ExponentialBackOffPolicy();
+
+		private final RetryPolicy retryPolicy = new NeverRetryPolicy();
+
+		@Bean
+		public RabbitRetryTemplateCustomizer rabbitTemplateRetryTemplateCustomizer() {
+			return (target, template) -> {
+				if (target.equals(RabbitRetryTemplateCustomizer.Target.SENDER)) {
+					template.setBackOffPolicy(this.backOffPolicy);
+				}
+			};
+		}
+
+		@Bean
+		public RabbitRetryTemplateCustomizer rabbitListenerRetryTemplateCustomizer() {
+			return (target, template) -> {
+				if (target.equals(RabbitRetryTemplateCustomizer.Target.LISTENER)) {
+					template.setRetryPolicy(this.retryPolicy);
+				}
+			};
+		}
+
+	}
+
 	@Configuration
 	@EnableRabbit
 	protected static class EnableRabbitConfiguration {

spring-boot-project/spring-boot-docs/src/main/asciidoc/spring-boot-features.adoc

@@ -5362,7 +5362,16 @@ If necessary, any `org.springframework.amqp.core.Queue` that is defined as a bea
 automatically used to declare a corresponding queue on the RabbitMQ instance.
 
 To retry operations, you can enable retries on the `AmqpTemplate` (for example, in the
-event that the broker connection is lost). Retries are disabled by default.
+event that the broker connection is lost):
+
+[source,properties,indent=0]
+----
+	spring.rabbitmq.template.retry.enabled=true
+	spring.rabbitmq.template.retry.initial-interval=2s
+----
+
+Retries are disabled by default. You can also customize the `RetryTemplate`
+programmatically by declaring a `RabbitRetryTemplateCustomizer` bean.
 
 
 
@@ -5444,7 +5453,8 @@ You can enable retries to handle situations where your listener throws an except
 default, `RejectAndDontRequeueRecoverer` is used, but you can define a `MessageRecoverer`
 of your own. When retries are exhausted, the message is rejected and either dropped or
 routed to a dead-letter exchange if the broker is configured to do so. By default,
-retries are disabled.
+retries are disabled. You can also customize the `RetryTemplate` programmatically by
+declaring a `RabbitRetryTemplateCustomizer` bean.
 
 IMPORTANT: By default, if retries are disabled and the listener throws an exception, the
 delivery is retried indefinitely. You can modify this behavior in two ways: Set the