Merge pull request #31495 from terminux

* pr/31495:
  Polish CompositeHandlerExceptionResolver
  Use ExceptionHandler when Spring MVC uses a different management port

Closes gh-31495

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/web/servlet/CompositeHandlerExceptionResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2022 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.
@@ -18,11 +18,12 @@
 
 import java.util.ArrayList;
 import java.util.List;
-import java.util.Objects;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.HierarchicalBeanFactory;
 import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.web.servlet.error.DefaultErrorAttributes;
@@ -38,34 +39,52 @@
  * @author Stephane Nicoll
  * @author Phillip Webb
  * @author Scott Frederick
+ * @author Guirong Hu
  */
 class CompositeHandlerExceptionResolver implements HandlerExceptionResolver {
 
 	@Autowired
 	private ListableBeanFactory beanFactory;
 
-	private List<HandlerExceptionResolver> resolvers;
+	private transient List<HandlerExceptionResolver> resolvers;
 
 	@Override
 	public ModelAndView resolveException(HttpServletRequest request, HttpServletResponse response, Object handler,
 			Exception ex) {
-		if (this.resolvers == null) {
-			this.resolvers = extractResolvers();
+		for (HandlerExceptionResolver resolver : getResolvers()) {
+			ModelAndView resolved = resolver.resolveException(request, response, handler, ex);
+			if (resolved != null) {
+				return resolved;
+			}
 		}
-		return this.resolvers.stream().map((resolver) -> resolver.resolveException(request, response, handler, ex))
-				.filter(Objects::nonNull).findFirst().orElse(null);
+		return null;
 	}
 
-	private List<HandlerExceptionResolver> extractResolvers() {
-		List<HandlerExceptionResolver> list = new ArrayList<>(
-				this.beanFactory.getBeansOfType(HandlerExceptionResolver.class).values());
-		list.remove(this);
-		AnnotationAwareOrderComparator.sort(list);
-		if (list.isEmpty()) {
-			list.add(new DefaultErrorAttributes());
-			list.add(new DefaultHandlerExceptionResolver());
+	private List<HandlerExceptionResolver> getResolvers() {
+		List<HandlerExceptionResolver> resolvers = this.resolvers;
+		if (resolvers == null) {
+			resolvers = new ArrayList<>();
+			collectResolverBeans(resolvers, this.beanFactory);
+			resolvers.remove(this);
+			AnnotationAwareOrderComparator.sort(resolvers);
+			if (resolvers.isEmpty()) {
+				resolvers.add(new DefaultErrorAttributes());
+				resolvers.add(new DefaultHandlerExceptionResolver());
+			}
+			this.resolvers = resolvers;
+		}
+		return resolvers;
+	}
+
+	private void collectResolverBeans(List<HandlerExceptionResolver> resolvers, BeanFactory beanFactory) {
+		if (beanFactory instanceof ListableBeanFactory) {
+			ListableBeanFactory listableBeanFactory = (ListableBeanFactory) beanFactory;
+			resolvers.addAll(listableBeanFactory.getBeansOfType(HandlerExceptionResolver.class).values());
+		}
+		if (beanFactory instanceof HierarchicalBeanFactory) {
+			HierarchicalBeanFactory hierarchicalBeanFactory = (HierarchicalBeanFactory) beanFactory;
+			collectResolverBeans(resolvers, hierarchicalBeanFactory.getParentBeanFactory());
 		}
-		return list;
 	}
 
 }

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-actuator/src/main/java/smoketest/actuator/SampleRestControllerEndpointWithException.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2012-2022 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 smoketest.actuator;
+
+import org.springframework.boot.actuate.endpoint.web.annotation.RestControllerEndpoint;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.stereotype.Component;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+
+/**
+ * The Sample rest controller endpoint with exception.
+ *
+ * @author Guirong Hu
+ */
+@Component
+@RestControllerEndpoint(id = "exception")
+public class SampleRestControllerEndpointWithException {
+
+	@GetMapping("/")
+	public String exception() {
+		throw new CustomException();
+	}
+
+	@RestControllerAdvice
+	static class CustomExceptionHandler {
+
+		@ExceptionHandler(CustomException.class)
+		ResponseEntity<String> handleCustomException(CustomException e) {
+			return new ResponseEntity<>("this is a custom exception body", HttpStatus.I_AM_A_TEAPOT);
+		}
+
+	}
+
+	static class CustomException extends RuntimeException {
+
+	}
+
+}

spring-boot-tests/spring-boot-smoke-tests/spring-boot-smoke-test-actuator/src/test/java/smoketest/actuator/ManagementDifferentPortAndEndpointWithExceptionHandlerSampleActuatorApplicationTests.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2012-2022 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 smoketest.actuator;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.actuate.autoconfigure.web.server.LocalManagementPort;
+import org.springframework.boot.actuate.endpoint.web.annotation.RestControllerEndpoint;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Integration tests for separate management and main service ports with Actuator's MVC
+ * {@link RestControllerEndpoint rest controller endpoints} and {@link ExceptionHandler
+ * exception handler}.
+ *
+ * @author Guirong Hu
+ */
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT,
+		properties = { "management.endpoints.web.exposure.include=*", "management.server.port=0" })
+class ManagementDifferentPortAndEndpointWithExceptionHandlerSampleActuatorApplicationTests {
+
+	@LocalManagementPort
+	private int managementPort;
+
+	@Test
+	void testExceptionHandlerRestControllerEndpoint() {
+		ResponseEntity<String> entity = new TestRestTemplate("user", "password")
+				.getForEntity("http://localhost:" + this.managementPort + "/actuator/exception", String.class);
+		assertThat(entity.getStatusCode()).isEqualTo(HttpStatus.I_AM_A_TEAPOT);
+		assertThat(entity.getBody()).isEqualTo("this is a custom exception body");
+	}
+
+}