Support non-standard error codes with AbstractErrorWebExceptionHandler

Fixes gh-16691

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/reactive/error/AbstractErrorWebExceptionHandler.java

@@ -62,6 +62,7 @@ public abstract class AbstractErrorWebExceptionHandler implements ErrorWebExcept
 	 * Currently duplicated from Spring WebFlux HttpWebHandlerAdapter.
 	 */
 	private static final Set<String> DISCONNECTED_CLIENT_EXCEPTIONS;
+
 	static {
 		Set<String> exceptions = new HashSet<>();
 		exceptions.add("AbortedException");
@@ -276,7 +277,8 @@ public abstract class AbstractErrorWebExceptionHandler implements ErrorWebExcept
 		if (logger.isDebugEnabled()) {
 			logger.debug(request.exchange().getLogPrefix() + formatError(throwable, request));
 		}
-		if (response.statusCode().equals(HttpStatus.INTERNAL_SERVER_ERROR)) {
+		if (HttpStatus.resolve(response.rawStatusCode()) != null
+				&& response.statusCode().equals(HttpStatus.INTERNAL_SERVER_ERROR)) {
 			logger.error(request.exchange().getLogPrefix() + "500 Server Error for " + formatRequest(request),
 					throwable);
 		}

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/reactive/error/DefaultErrorWebExceptionHandler.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.web.reactive.error;
 
 import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.EnumMap;
 import java.util.List;
@@ -113,16 +114,26 @@ public class DefaultErrorWebExceptionHandler extends AbstractErrorWebExceptionHa
 	protected Mono<ServerResponse> renderErrorView(ServerRequest request) {
 		boolean includeStackTrace = isIncludeStackTrace(request, MediaType.TEXT_HTML);
 		Map<String, Object> error = getErrorAttributes(request, includeStackTrace);
-		HttpStatus errorStatus = getHttpStatus(error);
+		int errorStatus = getHttpStatus(error);
 		ServerResponse.BodyBuilder responseBody = ServerResponse.status(errorStatus).contentType(TEXT_HTML_UTF8);
-		return Flux
-				.just("error/" + errorStatus.value(), "error/" + SERIES_VIEWS.get(errorStatus.series()), "error/error")
+		return Flux.just(getData(errorStatus).toArray(new String[] {}))
 				.flatMap((viewName) -> renderErrorView(viewName, responseBody, error))
 				.switchIfEmpty(this.errorProperties.getWhitelabel().isEnabled()
 						? renderDefaultErrorView(responseBody, error) : Mono.error(getError(request)))
 				.next();
 	}
 
+	private List<String> getData(int errorStatus) {
+		HttpStatus errorHttpStatus = HttpStatus.resolve(errorStatus);
+		List<String> data = new ArrayList<>();
+		data.add("error/" + errorStatus);
+		if (errorHttpStatus != null) {
+			data.add("error/" + SERIES_VIEWS.get(errorHttpStatus.series()));
+		}
+		data.add("error/error");
+		return data;
+	}
+
 	/**
 	 * Render the error information as a JSON payload.
 	 * @param request the current request
@@ -157,9 +168,8 @@ public class DefaultErrorWebExceptionHandler extends AbstractErrorWebExceptionHa
 	 * @param errorAttributes the current error information
 	 * @return the error HTTP status
 	 */
-	protected HttpStatus getHttpStatus(Map<String, Object> errorAttributes) {
-		int statusCode = (int) errorAttributes.get("status");
-		return HttpStatus.valueOf(statusCode);
+	protected int getHttpStatus(Map<String, Object> errorAttributes) {
+		return (int) errorAttributes.get("status");
 	}
 
 	/**

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/reactive/error/DefaultErrorWebExceptionHandlerTests.java

@@ -16,17 +16,37 @@
 
 package org.springframework.boot.autoconfigure.web.reactive.error;
 
+import java.util.Collections;
+import java.util.Map;
+
 import org.junit.jupiter.api.Test;
+import reactor.core.publisher.Mono;
 
+import org.springframework.boot.autoconfigure.web.ErrorProperties;
+import org.springframework.boot.autoconfigure.web.ResourceProperties;
+import org.springframework.boot.web.reactive.context.AnnotationConfigReactiveWebApplicationContext;
+import org.springframework.boot.web.reactive.error.ErrorAttributes;
+import org.springframework.context.ApplicationContext;
+import org.springframework.http.MediaType;
+import org.springframework.mock.http.server.reactive.MockServerHttpRequest;
+import org.springframework.mock.web.server.MockServerWebExchange;
 import org.springframework.test.util.ReflectionTestUtils;
+import org.springframework.web.reactive.result.view.View;
+import org.springframework.web.reactive.result.view.ViewResolver;
+import org.springframework.web.server.ServerWebExchange;
 import org.springframework.web.server.adapter.HttpWebHandlerAdapter;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyBoolean;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link AbstractErrorWebExceptionHandler}.
  *
  * @author Phillip Webb
+ * @author Madhura Bhave
  */
 class DefaultErrorWebExceptionHandlerTests {
 
@@ -39,4 +59,31 @@ class DefaultErrorWebExceptionHandlerTests {
 		assertThat(errorHandlers).isNotNull().isEqualTo(webHandlers);
 	}
 
+	@Test
+	void nonStandardErrorStatusCodeShouldNotFail() {
+		ErrorAttributes errorAttributes = mock(ErrorAttributes.class);
+		ResourceProperties resourceProperties = new ResourceProperties();
+		ErrorProperties errorProperties = new ErrorProperties();
+		ApplicationContext context = new AnnotationConfigReactiveWebApplicationContext();
+		given(errorAttributes.getErrorAttributes(any(), anyBoolean())).willReturn(getErrorAttributes());
+		DefaultErrorWebExceptionHandler exceptionHandler = new DefaultErrorWebExceptionHandler(errorAttributes,
+				resourceProperties, errorProperties, context);
+		setupViewResolver(exceptionHandler);
+		ServerWebExchange exchange = MockServerWebExchange
+				.from(MockServerHttpRequest.get("/some-other-path").accept(MediaType.TEXT_HTML));
+		exceptionHandler.handle(exchange, new RuntimeException()).block();
+	}
+
+	private Map<String, Object> getErrorAttributes() {
+		return Collections.singletonMap("status", 498);
+	}
+
+	private void setupViewResolver(DefaultErrorWebExceptionHandler exceptionHandler) {
+		View view = mock(View.class);
+		given(view.render(any(), any(), any())).willReturn(Mono.empty());
+		ViewResolver viewResolver = mock(ViewResolver.class);
+		given(viewResolver.resolveViewName(any(), any())).willReturn(Mono.just(view));
+		exceptionHandler.setViewResolvers(Collections.singletonList(viewResolver));
+	}
+
 }