GH-2456: Suppress Duplicate Annotations with Spy

Resolves #2456

When spying a `@RabbitListener` bean, duplicate methods are resolved as well
as duplicate class level `@RabbitListener` annotations.

**cherry-pick to 2.4.x** (will require instanceof polishing for Java 8)

Author: garyrussell

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/annotation/RabbitListenerAnnotationBeanPostProcessor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2022 the original author or authors.
+ * Copyright 2014-2023 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.
@@ -339,7 +339,8 @@ private TypeMetadata buildMetadata(Class<?> targetClass) {
 					multiMethods.add(method);
 				}
 			}
-		}, ReflectionUtils.USER_DECLARED_METHODS);
+		}, ReflectionUtils.USER_DECLARED_METHODS
+				.and(meth -> !meth.getDeclaringClass().getName().contains("$MockitoMock$")));
 		if (methods.isEmpty() && multiMethods.isEmpty()) {
 			return TypeMetadata.EMPTY;
 		}
@@ -352,14 +353,25 @@ private TypeMetadata buildMetadata(Class<?> targetClass) {
 	private List<RabbitListener> findListenerAnnotations(AnnotatedElement element) {
 		return MergedAnnotations.from(element, SearchStrategy.TYPE_HIERARCHY)
 				.stream(RabbitListener.class)
+				.filter(tma -> {
+					Object source = tma.getSource();
+					String name = "";
+					if (source instanceof Class<?>) {
+						name = ((Class<?>) source).getName();
+					}
+					else if (source instanceof Method) {
+						name = ((Method) source).getDeclaringClass().getName();
+					}
+					return !name.contains("$MockitoMock$");
+				})
 				.map(ann -> ann.synthesize())
 				.collect(Collectors.toList());
 	}
 
 	private void processMultiMethodListeners(RabbitListener[] classLevelListeners, Method[] multiMethods,
 			Object bean, String beanName) {
 
-		List<Method> checkedMethods = new ArrayList<Method>();
+		List<Method> checkedMethods = new ArrayList<>();
 		Method defaultMethod = null;
 		for (Method method : multiMethods) {
 			Method checked = checkProxy(method, bean);

spring-rabbit/src/test/java/org/springframework/amqp/rabbit/annotation/EnableRabbitIntegrationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2022 the original author or authors.
+ * Copyright 2014-2023 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.
@@ -19,8 +19,12 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.fail;
 import static org.awaitility.Awaitility.await;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.BDDMockito.willAnswer;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 
 import java.io.IOException;
 import java.io.Serializable;
@@ -385,6 +389,7 @@ public void multiListener() {
 		rabbitTemplate.convertAndSend("multi.exch", "multi.rk", bar);
 		assertThat(this.rabbitTemplate.receiveAndConvert("sendTo.replies"))
 				.isEqualTo("CRASHCRASH Test reply from error handler");
+		verify(this.multi, times(2)).bar(any());
 		bar.field = "bar";
 		Baz baz = new Baz();
 		baz.field = "baz";
@@ -400,7 +405,7 @@ public void multiListener() {
 		this.rabbitTemplate.setAfterReceivePostProcessors(mpp);
 		assertThat(rabbitTemplate.convertSendAndReceive("multi.exch", "multi.rk", qux)).isEqualTo("QUX: qux: multi.rk");
 		assertThat(beanMethodHeaders).hasSize(2);
-		assertThat(beanMethodHeaders.get(0)).isEqualTo("MultiListenerBean");
+		assertThat(beanMethodHeaders.get(0)).contains("$MultiListenerBean");
 		assertThat(beanMethodHeaders.get(1)).isEqualTo("qux");
 		this.rabbitTemplate.removeAfterReceivePostProcessor(mpp);
 		assertThat(rabbitTemplate.convertSendAndReceive("multi.exch.tx", "multi.rk.tx", bar)).isEqualTo("BAR: barbar");
@@ -1966,7 +1971,7 @@ public RabbitAdmin rabbitAdmin(ConnectionFactory connectionFactory) {
 
 		@Bean
 		public MultiListenerBean multiListener() {
-			return new MultiListenerBean();
+			return spy(new MultiListenerBean());
 		}
 
 		@Bean