Polish "Register controller advices to RSocket messaging"

See gh-45360

documentation/spring-boot-docs/src/docs/antora/modules/reference/pages/messaging/rsocket.adoc

@@ -69,6 +69,8 @@ Spring Boot will auto-configure the Spring Messaging infrastructure for RSocket.
 
 This means that Spring Boot will create a javadoc:org.springframework.messaging.rsocket.annotation.support.RSocketMessageHandler[] bean that will handle RSocket requests to your application.
 
+TIP: You can use {url-spring-framework-docs}/web/webmvc/mvc-controller/ann-advice.html[`@ControllerAdvice`] to handle exceptions.
+
 
 
 [[messaging.rsocket.requester]]

module/spring-boot-rsocket/src/main/java/org/springframework/boot/rsocket/autoconfigure/RSocketMessagingAutoConfiguration.java

@@ -26,6 +26,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
 import org.springframework.messaging.handler.MessagingAdviceBean;
 import org.springframework.messaging.rsocket.RSocketRequester;
 import org.springframework.messaging.rsocket.RSocketStrategies;
@@ -38,6 +39,7 @@ import org.springframework.web.method.ControllerAdviceBean;
  *
  * @author Brian Clozel
  * @author Dmitry Sulman
+ * @author Stephane Nicoll
  * @since 4.0.0
  */
 @AutoConfiguration(after = RSocketStrategiesAutoConfiguration.class)
@@ -51,10 +53,37 @@ public final class RSocketMessagingAutoConfiguration {
 		RSocketMessageHandler messageHandler = new RSocketMessageHandler();
 		messageHandler.setRSocketStrategies(rSocketStrategies);
 		customizers.orderedStream().forEach((customizer) -> customizer.customize(messageHandler));
-		ControllerAdviceBean.findAnnotatedBeans(context)
+
+		return messageHandler;
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@ConditionalOnClass(ControllerAdviceBean.class)
+	static class MessagingAdviceConfiguration {
+
+		@Bean
+		MessagingAdviceRSocketMessageHandlerCustomizer messagingAdviceRSocketMessageHandlerCustomizer(
+				ApplicationContext applicationContext) {
+			return new MessagingAdviceRSocketMessageHandlerCustomizer(applicationContext);
+		}
+
+	}
+
+	static final class MessagingAdviceRSocketMessageHandlerCustomizer implements RSocketMessageHandlerCustomizer {
+
+		private final ApplicationContext applicationContext;
+
+		MessagingAdviceRSocketMessageHandlerCustomizer(ApplicationContext applicationContext) {
+			this.applicationContext = applicationContext;
+		}
+
+		@Override
+		public void customize(RSocketMessageHandler messageHandler) {
+			ControllerAdviceBean.findAnnotatedBeans(this.applicationContext)
 				.forEach((controllerAdviceBean) -> messageHandler
 					.registerMessagingAdvice(new ControllerAdviceBeanWrapper(controllerAdviceBean)));
-		return messageHandler;
+		}
+
 	}
 
 	private static final class ControllerAdviceBeanWrapper implements MessagingAdviceBean {

module/spring-boot-rsocket/src/test/java/org/springframework/boot/rsocket/autoconfigure/RSocketMessagingAutoConfigurationTests.java

@@ -89,15 +89,14 @@ class RSocketMessagingAutoConfigurationTests {
 	void shouldRegisterControllerAdvice() {
 		this.contextRunner.withBean(TestControllerAdvice.class).withBean(TestController.class).run((context) -> {
 			RSocketMessageHandler handler = context.getBean(RSocketMessageHandler.class);
-			TestControllerAdvice controllerAdvice = context.getBean(TestControllerAdvice.class);
-
 			MessageHeaderAccessor headers = new MessageHeaderAccessor();
 			RouteMatcher.Route route = handler.getRouteMatcher().parseRoute("exception");
 			headers.setHeader(DestinationPatternsMessageCondition.LOOKUP_DESTINATION_HEADER, route);
 			headers.setHeader(RSocketFrameTypeMessageCondition.FRAME_TYPE_HEADER, FrameType.REQUEST_FNF);
 			Message<?> message = MessageBuilder.createMessage(Mono.empty(), headers.getMessageHeaders());
+
 			StepVerifier.create(handler.handleMessage(message)).expectComplete().verify();
-			assertThat(controllerAdvice.isExceptionHandled()).isTrue();
+			assertThat(context.getBean(TestControllerAdvice.class).isExceptionHandled()).isTrue();
 		});
 	}