GH-3869: Should fail bean registration when no method …

spring-kafka/src/main/java/org/springframework/kafka/annotation/KafkaListenerAnnotationBeanPostProcessor.java

@@ -407,13 +407,19 @@ public Object postProcessAfterInitialization(final Object bean, final String bea
 					this.logger.debug(() -> annotatedMethods.size() + " @KafkaListener methods processed on bean '"
 							+ beanName + "': " + annotatedMethods);
 				}
+				Set<Method> methodsWithHandler = MethodIntrospector.selectMethods(targetClass,
+						(ReflectionUtils.MethodFilter) method ->
+								AnnotationUtils.findAnnotation(method, KafkaHandler.class) != null);
+				boolean hasMethodLevelKafkaHandlerAnnotation = !methodsWithHandler.isEmpty();
 				if (hasClassLevelListeners) {
-					Set<Method> methodsWithHandler = MethodIntrospector.selectMethods(targetClass,
-							(ReflectionUtils.MethodFilter) method ->
-									AnnotationUtils.findAnnotation(method, KafkaHandler.class) != null);
 					List<Method> multiMethods = new ArrayList<>(methodsWithHandler);
 					processMultiMethodListeners(classLevelListeners, multiMethods, targetClass, bean, beanName);
 				}
+
+				if (!hasMethodLevelListeners && hasClassLevelListeners &&
+					!hasMethodLevelKafkaHandlerAnnotation) {
+					throw new IllegalStateException("No kafka listener methods found on bean type.");
+				}
 			}
 		}
 		return bean;

spring-kafka/src/test/java/org/springframework/kafka/annotation/KafkaListenerAnnotationBeanPostProcessorTests.java

@@ -0,0 +1,63 @@
+/*
+ * Copyright 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://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.kafka.annotation;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.stereotype.Component;
+
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+/**
+ * @author Sanghyeok An
+ *
+ * @since 4.0.0
+ */
+
+class KafkaListenerAnnotationBeanPostProcessorTests {
+
+	@Test
+	void ctx_should_be_fail_to_register_bean_when_no_listener_methods_exist() {
+
+		AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
+		ctx.register(TestConfig.class);
+
+		assertThatExceptionOfType(BeanCreationException.class)
+				.isThrownBy(ctx::refresh)
+				.withMessageContaining("No kafka listener methods found on bean type.")
+				.withMessageContaining("NoHandlerMethodListener");
+
+	}
+
+	@EnableKafka
+	@Configuration
+	static class TestConfig {
+
+		@Component
+		@KafkaListener
+		static class NoHandlerMethodListener {
+
+			public void listen(String message) {
+			}
+		}
+
+	}
+
+}