Closes gh-21428

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

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -19,6 +19,7 @@ package org.springframework.boot.actuate.autoconfigure.web.servlet;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
+import java.util.Optional;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -36,6 +37,7 @@ import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolv
  * @author Andy Wilkinson
  * @author Stephane Nicoll
  * @author Phillip Webb
+ * @author Scott Frederick
  */
 class CompositeHandlerExceptionResolver implements HandlerExceptionResolver {
 
@@ -50,8 +52,15 @@ class CompositeHandlerExceptionResolver implements HandlerExceptionResolver {
 		if (this.resolvers == null) {
 			this.resolvers = extractResolvers();
 		}
-		return this.resolvers.stream().map((resolver) -> resolver.resolveException(request, response, handler, ex))
-				.filter(Objects::nonNull).findFirst().orElse(null);
+		Optional<ModelAndView> modelAndView = this.resolvers.stream()
+				.map((resolver) -> resolver.resolveException(request, response, handler, ex)).filter(Objects::nonNull)
+				.findFirst();
+		modelAndView.ifPresent((mav) -> {
+			if (mav.isEmpty()) {
+				request.setAttribute("javax.servlet.error.exception", ex);
+			}
+		});
+		return modelAndView.orElse(null);
 	}
 
 	private List<HandlerExceptionResolver> extractResolvers() {

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/web/servlet/CompositeHandlerExceptionResolverTests.java

 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2020 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.
@@ -38,6 +38,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  * Tests for {@link CompositeHandlerExceptionResolver}.
  *
  * @author Madhura Bhave
+ * @author Scott Frederick
  */
 class CompositeHandlerExceptionResolverTests {
 
@@ -62,9 +63,11 @@ class CompositeHandlerExceptionResolverTests {
 		load(BaseConfiguration.class);
 		CompositeHandlerExceptionResolver resolver = (CompositeHandlerExceptionResolver) this.context
 				.getBean(DispatcherServlet.HANDLER_EXCEPTION_RESOLVER_BEAN_NAME);
-		ModelAndView resolved = resolver.resolveException(this.request, this.response, null,
-				new HttpRequestMethodNotSupportedException("POST"));
+		HttpRequestMethodNotSupportedException exception = new HttpRequestMethodNotSupportedException("POST");
+		ModelAndView resolved = resolver.resolveException(this.request, this.response, null, exception);
 		assertThat(resolved).isNotNull();
+		assertThat(resolved.isEmpty()).isTrue();
+		assertThat(this.request.getAttribute("javax.servlet.error.exception")).isSameAs(exception);
 	}
 
 	private void load(Class<?>... configs) {

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/web/servlet/WebMvcEndpointChildContextConfigurationIntegrationTests.java

@@ -16,7 +16,12 @@
 
 package org.springframework.boot.actuate.autoconfigure.web.servlet;
 
+import java.util.Collections;
 import java.util.Map;
+import java.util.function.Consumer;
+
+import javax.validation.Valid;
+import javax.validation.constraints.NotEmpty;
 
 import org.junit.jupiter.api.Test;
 
@@ -25,15 +30,21 @@ import org.springframework.boot.actuate.autoconfigure.endpoint.web.WebEndpointAu
 import org.springframework.boot.actuate.autoconfigure.web.server.ManagementContextAutoConfiguration;
 import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
 import org.springframework.boot.actuate.endpoint.annotation.ReadOperation;
+import org.springframework.boot.actuate.endpoint.web.annotation.RestControllerEndpoint;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.autoconfigure.web.servlet.DispatcherServletAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryAutoConfiguration;
 import org.springframework.boot.autoconfigure.web.servlet.error.ErrorMvcAutoConfiguration;
+import org.springframework.boot.test.context.assertj.AssertableWebApplicationContext;
+import org.springframework.boot.test.context.runner.ContextConsumer;
 import org.springframework.boot.test.context.runner.WebApplicationContextRunner;
 import org.springframework.boot.web.context.ServerPortInfoApplicationContextInitializer;
 import org.springframework.boot.web.servlet.context.AnnotationConfigServletWebServerApplicationContext;
 import org.springframework.http.MediaType;
-import org.springframework.stereotype.Component;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.ResponseBody;
 import org.springframework.web.reactive.function.client.ClientResponse;
 import org.springframework.web.reactive.function.client.WebClient;
 
@@ -54,40 +65,80 @@ class WebMvcEndpointChildContextConfigurationIntegrationTests {
 							ServletManagementContextAutoConfiguration.class, WebEndpointAutoConfiguration.class,
 							EndpointAutoConfiguration.class, DispatcherServletAutoConfiguration.class,
 							ErrorMvcAutoConfiguration.class))
-					.withUserConfiguration(FailingEndpoint.class)
-					.withInitializer(new ServerPortInfoApplicationContextInitializer()).withPropertyValues(
-							"server.port=0", "management.server.port=0", "management.endpoints.web.exposure.include=*");
+					.withUserConfiguration(FailingEndpoint.class, FailingControllerEndpoint.class)
+					.withInitializer(new ServerPortInfoApplicationContextInitializer())
+					.withPropertyValues("server.port=0", "management.server.port=0",
+							"management.endpoints.web.exposure.include=*", "server.error.include-exception=true",
+							"server.error.include-message=always", "server.error.include-binding-errors=always");
 
 	@Test // gh-17938
-	@SuppressWarnings("unchecked")
-	void errorPageAndErrorControllerAreUsed() {
-		this.runner.run((context) -> {
-			String port = context.getEnvironment().getProperty("local.management.port");
-			WebClient client = WebClient.create("http://localhost:" + port);
+	void errorEndpointIsUsedWithEndpoint() {
+		this.runner.run(withWebTestClient((client) -> {
 			ClientResponse response = client.get().uri("actuator/fail").accept(MediaType.APPLICATION_JSON).exchange()
 					.block();
-			Map<Object, Object> body = response.bodyToMono(Map.class).block();
-			assertThat(body).containsEntry("message", "");
-			assertThat(body).doesNotContainKey("trace");
-		});
+			Map<String, ?> body = getResponseBody(response);
+			assertThat(body).hasEntrySatisfying("exception",
+					(value) -> assertThat(value).asString().contains("IllegalStateException"));
+			assertThat(body).hasEntrySatisfying("message",
+					(value) -> assertThat(value).asString().contains("Epic Fail"));
+		}));
 	}
 
 	@Test
 	void errorPageAndErrorControllerIncludeDetails() {
 		this.runner.withPropertyValues("server.error.include-stacktrace=always", "server.error.include-message=always")
-				.run((context) -> {
-					String port = context.getEnvironment().getProperty("local.management.port");
-					WebClient client = WebClient.create("http://localhost:" + port);
+				.run(withWebTestClient((client) -> {
 					ClientResponse response = client.get().uri("actuator/fail").accept(MediaType.APPLICATION_JSON)
 							.exchange().block();
-					Map<Object, Object> body = response.bodyToMono(Map.class).block();
-					assertThat(body).containsEntry("message", "Epic Fail");
+					Map<String, ?> body = getResponseBody(response);
+					assertThat(body).hasEntrySatisfying("message",
+							(value) -> assertThat(value).asString().contains("Epic Fail"));
 					assertThat(body).hasEntrySatisfying("trace", (value) -> assertThat(value).asString()
 							.contains("java.lang.IllegalStateException: Epic Fail"));
-				});
+				}));
+	}
+
+	@Test
+	void errorEndpointIsUsedWithRestControllerEndpoint() {
+		this.runner.run(withWebTestClient((client) -> {
+			ClientResponse response = client.get().uri("actuator/failController").accept(MediaType.APPLICATION_JSON)
+					.exchange().block();
+			Map<String, ?> body = getResponseBody(response);
+			assertThat(body).hasEntrySatisfying("exception",
+					(value) -> assertThat(value).asString().contains("IllegalStateException"));
+			assertThat(body).hasEntrySatisfying("message",
+					(value) -> assertThat(value).asString().contains("Epic Fail"));
+		}));
+	}
+
+	@Test
+	void errorEndpointIsUsedWithRestControllerEndpointOnBindingError() {
+		this.runner.run(withWebTestClient((client) -> {
+			ClientResponse response = client.post().uri("actuator/failController")
+					.bodyValue(Collections.singletonMap("content", "")).accept(MediaType.APPLICATION_JSON).exchange()
+					.block();
+			Map<String, ?> body = getResponseBody(response);
+			assertThat(body).hasEntrySatisfying("exception",
+					(value) -> assertThat(value).asString().contains("MethodArgumentNotValidException"));
+			assertThat(body).hasEntrySatisfying("message",
+					(value) -> assertThat(value).asString().contains("Validation failed"));
+			assertThat(body).hasEntrySatisfying("errors", (value) -> assertThat(value).asList().isNotEmpty());
+		}));
+	}
+
+	private ContextConsumer<AssertableWebApplicationContext> withWebTestClient(Consumer<WebClient> webClient) {
+		return (context) -> {
+			String port = context.getEnvironment().getProperty("local.management.port");
+			WebClient client = WebClient.create("http://localhost:" + port);
+			webClient.accept(client);
+		};
+	}
+
+	@SuppressWarnings("unchecked")
+	private Map<String, ?> getResponseBody(ClientResponse response) {
+		return (Map<String, ?>) response.bodyToMono(Map.class).block();
 	}
 
-	@Component
 	@Endpoint(id = "fail")
 	static class FailingEndpoint {
 
@@ -98,4 +149,35 @@ class WebMvcEndpointChildContextConfigurationIntegrationTests {
 
 	}
 
+	@RestControllerEndpoint(id = "failController")
+	static class FailingControllerEndpoint {
+
+		@GetMapping
+		String fail() {
+			throw new IllegalStateException("Epic Fail");
+		}
+
+		@PostMapping(produces = "application/json")
+		@ResponseBody
+		String bodyValidation(@Valid @RequestBody TestBody body) {
+			return body.getContent();
+		}
+
+	}
+
+	public static class TestBody {
+
+		@NotEmpty
+		private String content;
+
+		public String getContent() {
+			return this.content;
+		}
+
+		public void setContent(String content) {
+			this.content = content;
+		}
+
+	}
+
 }