Headers support in ResponseStatusExceptionResolver

Closes gh-24944

Author: rstoyanchev

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/annotation/ResponseStatusExceptionResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -115,8 +115,10 @@ protected ModelAndView resolveResponseStatus(ResponseStatus responseStatus, Http
 
 	/**
 	 * Template method that handles an {@link ResponseStatusException}.
-	 * <p>The default implementation delegates to {@link #applyStatusAndReason}
-	 * with the status code and reason from the exception.
+	 * <p>The default implementation applies the headers from
+	 * {@link ResponseStatusException#getResponseHeaders()} and delegates to
+	 * {@link #applyStatusAndReason} with the status code and reason from the
+	 * exception.
 	 * @param ex the exception
 	 * @param request current HTTP request
 	 * @param response current HTTP response
@@ -128,6 +130,12 @@ protected ModelAndView resolveResponseStatus(ResponseStatus responseStatus, Http
 	protected ModelAndView resolveResponseStatusException(ResponseStatusException ex,
 			HttpServletRequest request, HttpServletResponse response, @Nullable Object handler) throws Exception {
 
+		ex.getResponseHeaders().forEach((name, values) -> {
+			if (response.getHeader(name) == null) {
+				values.forEach(value -> response.addHeader(name, value));
+			}
+		});
+
 		int statusCode = ex.getStatus().value();
 		String reason = ex.getReason();
 		return applyStatusAndReason(statusCode, reason, response);

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/annotation/ResponseStatusExceptionResolverTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 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.
@@ -18,6 +18,7 @@
 
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
+import java.util.Arrays;
 import java.util.Locale;
 
 import org.junit.jupiter.api.BeforeEach;
@@ -28,8 +29,11 @@
 import org.springframework.context.i18n.LocaleContextHolder;
 import org.springframework.context.support.StaticMessageSource;
 import org.springframework.core.annotation.AliasFor;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 import org.springframework.web.bind.annotation.ResponseStatus;
+import org.springframework.web.server.MethodNotAllowedException;
 import org.springframework.web.server.ResponseStatusException;
 import org.springframework.web.servlet.ModelAndView;
 import org.springframework.web.testfixture.servlet.MockHttpServletRequest;
@@ -128,6 +132,16 @@ public void responseStatusExceptionWithReason() throws Exception {
 		assertResolved(mav, 400, "The reason");
 	}
 
+	@Test
+	void responseStatusExceptionWithHeaders() {
+		Exception ex = new MethodNotAllowedException(
+				HttpMethod.GET, Arrays.asList(HttpMethod.POST, HttpMethod.PUT));
+
+		ModelAndView mav = exceptionResolver.resolveException(request, response, null, ex);
+
+		assertResolved(mav, 405, "Request method 'GET' not supported");
+		assertThat(response.getHeader(HttpHeaders.ALLOW)).isEqualTo("POST,PUT");
+	}
 
 	private void assertResolved(ModelAndView mav, int status, String reason) {
 		assertThat(mav != null && mav.isEmpty()).as("No Empty ModelAndView returned").isTrue();