Improve ResponseStatusException to use reason as detailMessageCode if…

… present

detail in ProblemDetail will be localized
Closes GH-30222

spring-web/src/main/java/org/springframework/web/server/ResponseStatusException.java

@@ -20,6 +20,7 @@
 import org.springframework.http.HttpStatusCode;
 import org.springframework.http.ProblemDetail;
 import org.springframework.lang.Nullable;
+import org.springframework.util.StringUtils;
 import org.springframework.web.ErrorResponseException;
 
 /**
@@ -29,6 +30,7 @@
  *
  * @author Rossen Stoyanchev
  * @author Juergen Hoeller
+ * @author Yanming Zhou
  * @since 5.0
  */
 @SuppressWarnings("serial")
@@ -132,4 +134,11 @@ public String getMessage() {
 		return getStatusCode() + (this.reason != null ? " \"" + this.reason + "\"" : "");
 	}
 
+	@Override
+	public String getDetailMessageCode() {
+		if (StringUtils.hasLength(this.reason)) {
+			return this.reason;
+		}
+		return super.getDetailMessageCode();
+	}
 }

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

@@ -58,6 +58,7 @@
 import org.springframework.web.context.request.async.AsyncRequestTimeoutException;
 import org.springframework.web.context.support.StaticWebApplicationContext;
 import org.springframework.web.multipart.support.MissingServletRequestPartException;
+import org.springframework.web.server.ResponseStatusException;
 import org.springframework.web.servlet.DispatcherServlet;
 import org.springframework.web.servlet.ModelAndView;
 import org.springframework.web.servlet.NoHandlerFoundException;
@@ -72,6 +73,7 @@
  * Unit tests for {@link ResponseEntityExceptionHandler}.
  *
  * @author Rossen Stoyanchev
+ * @author Yanming Zhou
  */
 public class ResponseEntityExceptionHandlerTests {
 
@@ -189,6 +191,30 @@ public void errorResponseProblemDetailViaMessageSource() {
 		}
 	}
 
+	@Test
+	public void useResponseStatusExceptionReasonAsDetailMessageCodeIfPresent() {
+
+		Locale locale = Locale.UK;
+		LocaleContextHolder.setLocale(locale);
+
+		String code = "bad.request";
+		String message = "Breaking Bad Request";
+		try {
+			StaticMessageSource messageSource = new StaticMessageSource();
+			messageSource.addMessage(code, locale, message);
+
+			this.exceptionHandler.setMessageSource(messageSource);
+
+			ResponseEntity<?> entity = testException(new ResponseStatusException(HttpStatus.BAD_REQUEST, code));
+
+			ProblemDetail body = (ProblemDetail) entity.getBody();
+			assertThat(body.getDetail()).isEqualTo(message);
+		}
+		finally {
+			LocaleContextHolder.resetLocaleContext();
+		}
+	}
+
 	@Test
 	public void conversionNotSupported() {
 		testException(new ConversionNotSupportedException(new Object(), Object.class, null));