Add RequestHandlerRetryAdvice.setBackOff()

The `RetryAdviceParser` uses a private constructor of the `org.springframework.core.retry.DefaultRetryPolicy`
for almost nothing.
It is better to propagate a `BackOff` bean definition down to the target `RequestHandlerRetryAdvice` API.

* Add `RequestHandlerRetryAdvice.setBackOff()` and use it from the `RetryAdviceParser` instead of the `retryPolicy` property.
* This also makes the end-user experience with `RequestHandlerRetryAdvice` better when we care really only about a `BackOff`

Related to: spring-projects/spring-framework#35963

Author: artembilan

spring-integration-core/src/main/java/org/springframework/integration/config/xml/RetryAdviceParser.java

@@ -16,9 +16,6 @@
 
 package org.springframework.integration.config.xml;
 
-import java.time.Duration;
-import java.util.Set;
-
 import org.w3c.dom.Element;
 
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
@@ -71,15 +68,7 @@ protected AbstractBeanDefinition parseInternal(Element element, ParserContext pa
 			}
 		}
 
-		BeanDefinitionBuilder retryPolicyBuilder =
-				BeanDefinitionBuilder.genericBeanDefinition("org.springframework.core.retry.DefaultRetryPolicy")
-						.addConstructorArgValue(Set.of())
-						.addConstructorArgValue(Set.of())
-						.addConstructorArgValue(null)
-						.addConstructorArgValue(Duration.ZERO)
-						.addConstructorArgValue(backOffBuilder.getBeanDefinition());
-
-		builder.addPropertyValue("retryPolicy", retryPolicyBuilder.getBeanDefinition());
+		builder.addPropertyValue("backOff", backOffBuilder.getBeanDefinition());
 		String recoveryChannelAttr = element.getAttribute("recovery-channel");
 		if (StringUtils.hasText(recoveryChannelAttr)) {
 			BeanDefinitionBuilder emsrBuilder =

spring-integration-core/src/main/java/org/springframework/integration/handler/advice/RequestHandlerRetryAdvice.java

@@ -39,6 +39,7 @@
 import org.springframework.integration.support.ErrorMessageUtils;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessagingException;
+import org.springframework.util.backoff.BackOff;
 import org.springframework.util.backoff.BackOffExecution;
 
 /**
@@ -99,13 +100,25 @@ public RequestHandlerRetryAdvice() {
 	/**
 	 * Set a {@link RetryPolicy} to use.
 	 * Defaults to 3 attempts with no delay in between.
+	 * Mutually exclusive with {@link #setBackOff(BackOff)}.
 	 * @param retryPolicy the policy.
 	 */
 	public void setRetryPolicy(RetryPolicy retryPolicy) {
 		this.retryPolicy = retryPolicy;
 		this.retryTemplate.setRetryPolicy(this.retryPolicy);
 	}
 
+	/**
+	 * Set a {@link BackOff} to be used in the internal {@link RetryPolicy} with rest options as defaults.
+	 * Mutually exclusive with {@link #setRetryPolicy(RetryPolicy)}.
+	 * @param backOff the back-off.
+	 * @since 7.0.1
+	 */
+	public void setBackOff(BackOff backOff) {
+		this.retryPolicy = RetryPolicy.builder().backOff(backOff).build();
+		this.retryTemplate.setRetryPolicy(this.retryPolicy);
+	}
+
 	/**
 	 * Set a {@link RetryListener} to track retry cycle phases.
 	 * @param retryListener the listener to use.