GH-9985: Fix NPE in ReqHandlerRetryAdvice with MetricsRetryListener

Fixes: #9985
Issue link: #9985

When `RequestHandlerRetryAdvice` is supplied with a `RetryTemplate` and `MetricsRetryListener`,
the `NullPointerException` is thrown from the Micrometer `Timer`, where `name` tag cannot be `null`.
In fact, the `RetryCallback` implementation in the `RequestHandlerRetryAdvice` does not provide any `label`.

* Fix `RequestHandlerRetryAdvice` to produce label based on the `componentName` or just class name of the
AOP caller as fallback

**Auto-cherry-pick to `6.4.x` & `6.3.x`**

Author: artembilan

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.integration.handler.advice;
 
+import org.springframework.integration.handler.AbstractReplyProducingMessageHandler;
 import org.springframework.integration.support.ErrorMessageUtils;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessagingException;
@@ -78,7 +79,7 @@ protected void onInit() {
 
 	@Override
 	protected Object doInvoke(ExecutionCallback callback, Object target, Message<?> message) {
-		IntegrationRetryCallback retryCallback = new IntegrationRetryCallback(message, callback);
+		IntegrationRetryCallback retryCallback = new IntegrationRetryCallback(message, callback, target);
 		RetryState retryState = this.retryStateGenerator.determineRetryState(message);
 		try {
 			return this.retryTemplate.execute(retryCallback, this.recoveryCallback, retryState);
@@ -113,14 +114,21 @@ public <T, E extends Throwable> boolean open(RetryContext context, RetryCallback
 
 	}
 
-	private record IntegrationRetryCallback(Message<?> messageToTry, ExecutionCallback callback)
+	private record IntegrationRetryCallback(Message<?> messageToTry, ExecutionCallback callback, Object target)
 			implements RetryCallback<Object, Exception> {
 
 		@Override
 		public Object doWithRetry(RetryContext context) {
 			return this.callback.cloneAndExecute();
 		}
 
+		@Override
+		public String getLabel() {
+			return this.target instanceof AbstractReplyProducingMessageHandler.RequestHandler requestHandler
+					? requestHandler.getAdvisedHandler().getComponentName()
+					: this.target.getClass().getName();
+		}
+
 	}
 
 }

spring-integration-core/src/test/java/org/springframework/integration/handler/advice/AdvisedMessageHandlerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2024 the original author or authors.
+ * Copyright 2002-2025 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.
@@ -29,6 +29,9 @@
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
 
+import io.micrometer.core.instrument.MeterRegistry;
+import io.micrometer.core.instrument.Timer;
+import io.micrometer.core.instrument.simple.SimpleMeterRegistry;
 import org.aopalliance.aop.Advice;
 import org.aopalliance.intercept.MethodInterceptor;
 import org.aopalliance.intercept.MethodInvocation;
@@ -58,6 +61,7 @@
 import org.springframework.retry.RetryContext;
 import org.springframework.retry.policy.SimpleRetryPolicy;
 import org.springframework.retry.support.DefaultRetryState;
+import org.springframework.retry.support.MetricsRetryListener;
 import org.springframework.retry.support.RetryTemplate;
 import org.springframework.scheduling.TaskScheduler;
 import org.springframework.test.annotation.DirtiesContext;
@@ -993,6 +997,46 @@ public void enhancedRecoverer() {
 		assertThat(((ErrorMessage) error).getOriginalMessage().getPayload()).isEqualTo("foo");
 	}
 
+	@Test
+	public void retryAdviceWithMetricsListener() {
+		AbstractReplyProducingMessageHandler handler = new AbstractReplyProducingMessageHandler() {
+
+			@Override
+			protected Object handleRequestMessage(Message<?> requestMessage) {
+				throw new RuntimeException("intentional");
+			}
+		};
+
+		MeterRegistry meterRegistry = new SimpleMeterRegistry();
+
+		RequestHandlerRetryAdvice advice = new RequestHandlerRetryAdvice();
+		RetryTemplate retryTemplate = new RetryTemplate();
+		retryTemplate.registerListener(new MetricsRetryListener(meterRegistry));
+		advice.setRetryTemplate(retryTemplate);
+		advice.setBeanFactory(mock(BeanFactory.class));
+		advice.afterPropertiesSet();
+
+		List<Advice> adviceChain = new ArrayList<>();
+		adviceChain.add(advice);
+		handler.setAdviceChain(adviceChain);
+		handler.setBeanName("testEndpoint");
+		handler.setBeanFactory(mock(BeanFactory.class));
+		handler.afterPropertiesSet();
+
+		Message<String> message = new GenericMessage<>("Hello, world!");
+		assertThatExceptionOfType(MessagingException.class)
+				.isThrownBy(() -> handler.handleMessage(message))
+				.withRootCauseInstanceOf(RuntimeException.class)
+				.withStackTraceContaining("intentional");
+
+		Timer retryTimer = meterRegistry.find(MetricsRetryListener.TIMER_NAME)
+				.tag("name", "testEndpoint")
+				.tag("retry.count", "3")
+				.timer();
+
+		assertThat(retryTimer.count()).isEqualTo(1);
+	}
+
 	private interface Bar {
 
 		Object handleRequestMessage(Message<?> message) throws Throwable;