DefaultHandlerExceptionResolver logs warn entries for conversion exceptions

Issue: SPR-13267

Author: jhoeller

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/support/DefaultHandlerExceptionResolver.java

@@ -56,12 +56,13 @@
  * HandlerExceptionResolver} interface that resolves standard Spring exceptions and translates
  * them to corresponding HTTP status codes.
  *
- * <p>This exception resolver is enabled by default in the {@link org.springframework.web.servlet.DispatcherServlet}.
+ * <p>This exception resolver is enabled by default in the common Spring
+ * {@link org.springframework.web.servlet.DispatcherServlet}.
  *
  * @author Arjen Poutsma
  * @author Rossen Stoyanchev
+ * @author Juergen Hoeller
  * @since 3.0
- *
  * @see org.springframework.web.servlet.mvc.method.annotation.ResponseEntityExceptionHandler
  * @see #handleNoSuchRequestHandlingMethod
  * @see #handleHttpRequestMethodNotSupported
@@ -145,10 +146,12 @@ else if (ex instanceof HttpMessageNotWritableException) {
 				return handleHttpMessageNotWritable((HttpMessageNotWritableException) ex, request, response, handler);
 			}
 			else if (ex instanceof MethodArgumentNotValidException) {
-				return handleMethodArgumentNotValidException((MethodArgumentNotValidException) ex, request, response, handler);
+				return handleMethodArgumentNotValidException((MethodArgumentNotValidException) ex, request, response,
+						handler);
 			}
 			else if (ex instanceof MissingServletRequestPartException) {
-				return handleMissingServletRequestPartException((MissingServletRequestPartException) ex, request, response, handler);
+				return handleMissingServletRequestPartException((MissingServletRequestPartException) ex, request,
+						response, handler);
 			}
 			else if (ex instanceof BindException) {
 				return handleBindException((BindException) ex, request, response, handler);
@@ -158,7 +161,9 @@ else if (ex instanceof NoHandlerFoundException) {
 			}
 		}
 		catch (Exception handlerException) {
-			logger.warn("Handling of [" + ex.getClass().getName() + "] resulted in Exception", handlerException);
+			if (logger.isWarnEnabled()) {
+				logger.warn("Handling of [" + ex.getClass().getName() + "] resulted in Exception", handlerException);
+			}
 		}
 		return null;
 	}
@@ -211,9 +216,10 @@ protected ModelAndView handleHttpRequestMethodNotSupported(HttpRequestMethodNotS
 
 	/**
 	 * Handle the case where no {@linkplain org.springframework.http.converter.HttpMessageConverter message converters}
-	 * were found for the PUT or POSTed content. <p>The default implementation sends an HTTP 415 error,
-	 * sets the "Accept" header, and returns an empty {@code ModelAndView}. Alternatively, a fallback
-	 * view could be chosen, or the HttpMediaTypeNotSupportedException could be rethrown as-is.
+	 * were found for the PUT or POSTed content.
+	 * <p>The default implementation sends an HTTP 415 error, sets the "Accept" header,
+	 * and returns an empty {@code ModelAndView}. Alternatively, a fallback view could
+	 * be chosen, or the HttpMediaTypeNotSupportedException could be rethrown as-is.
 	 * @param ex the HttpMediaTypeNotSupportedException to be handled
 	 * @param request current HTTP request
 	 * @param response current HTTP response
@@ -305,7 +311,7 @@ protected ModelAndView handleMissingServletRequestParameter(MissingServletReques
 	protected ModelAndView handleServletRequestBindingException(ServletRequestBindingException ex,
 			HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {
 
-		response.sendError(HttpServletResponse.SC_BAD_REQUEST);
+		response.sendError(HttpServletResponse.SC_BAD_REQUEST, ex.getMessage());
 		return new ModelAndView();
 	}
 
@@ -323,21 +329,13 @@ protected ModelAndView handleServletRequestBindingException(ServletRequestBindin
 	protected ModelAndView handleConversionNotSupported(ConversionNotSupportedException ex,
 			HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {
 
+		if (logger.isWarnEnabled()) {
+			logger.warn("Failed to convert request element: " + ex);
+		}
 		sendServerError(ex, request, response);
 		return new ModelAndView();
 	}
 
-	/**
-	 * Invoked to send a server error. Sets the status to 500 and also sets the
-	 * request attribute "javax.servlet.error.exception" to the Exception.
-	 */
-	protected void sendServerError(Exception ex,
-			HttpServletRequest request, HttpServletResponse response) throws IOException {
-
-		request.setAttribute("javax.servlet.error.exception", ex);
-		response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
-	}
-
 	/**
 	 * Handle the case when a {@link org.springframework.web.bind.WebDataBinder} conversion error occurs.
 	 * <p>The default implementation sends an HTTP 400 error, and returns an empty {@code ModelAndView}.
@@ -352,6 +350,9 @@ protected void sendServerError(Exception ex,
 	protected ModelAndView handleTypeMismatch(TypeMismatchException ex,
 			HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {
 
+		if (logger.isWarnEnabled()) {
+			logger.warn("Failed to bind request element: " + ex);
+		}
 		response.sendError(HttpServletResponse.SC_BAD_REQUEST);
 		return new ModelAndView();
 	}
@@ -372,6 +373,9 @@ protected ModelAndView handleTypeMismatch(TypeMismatchException ex,
 	protected ModelAndView handleHttpMessageNotReadable(HttpMessageNotReadableException ex,
 			HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {
 
+		if (logger.isWarnEnabled()) {
+			logger.warn("Failed to read HTTP message: " + ex);
+		}
 		response.sendError(HttpServletResponse.SC_BAD_REQUEST);
 		return new ModelAndView();
 	}
@@ -392,6 +396,9 @@ protected ModelAndView handleHttpMessageNotReadable(HttpMessageNotReadableExcept
 	protected ModelAndView handleHttpMessageNotWritable(HttpMessageNotWritableException ex,
 			HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {
 
+		if (logger.isWarnEnabled()) {
+			logger.warn("Failed to write HTTP message: " + ex);
+		}
 		sendServerError(ex, request, response);
 		return new ModelAndView();
 	}
@@ -408,6 +415,7 @@ protected ModelAndView handleHttpMessageNotWritable(HttpMessageNotWritableExcept
 	 */
 	protected ModelAndView handleMethodArgumentNotValidException(MethodArgumentNotValidException ex,
 			HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {
+
  		response.sendError(HttpServletResponse.SC_BAD_REQUEST);
 		return new ModelAndView();
 	}
@@ -424,6 +432,7 @@ protected ModelAndView handleMethodArgumentNotValidException(MethodArgumentNotVa
 	 */
 	protected ModelAndView handleMissingServletRequestPartException(MissingServletRequestPartException ex,
 			HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {
+
 		response.sendError(HttpServletResponse.SC_BAD_REQUEST, ex.getMessage());
 		return new ModelAndView();
 	}
@@ -432,7 +441,7 @@ protected ModelAndView handleMissingServletRequestPartException(MissingServletRe
 	 * Handle the case where an {@linkplain ModelAttribute @ModelAttribute} method
 	 * argument has binding or validation errors and is not followed by another
 	 * method argument of type {@link BindingResult}.
-	 * By default an HTTP 400 error is sent back to the client.
+	 * By default, an HTTP 400 error is sent back to the client.
 	 * @param request current HTTP request
 	 * @param response current HTTP response
 	 * @param handler the executed handler
@@ -441,14 +450,15 @@ protected ModelAndView handleMissingServletRequestPartException(MissingServletRe
 	 */
 	protected ModelAndView handleBindException(BindException ex, HttpServletRequest request,
 			HttpServletResponse response, Object handler) throws IOException {
+
 		response.sendError(HttpServletResponse.SC_BAD_REQUEST);
 		return new ModelAndView();
 	}
 
 	/**
 	 * Handle the case where no handler was found during the dispatch.
-	 * <p>The default sends an HTTP 404 error, and returns
-	 * an empty {@code ModelAndView}. Alternatively, a fallback view could be chosen,
+	 * <p>The default implementation sends an HTTP 404 error and returns an empty
+	 * {@code ModelAndView}. Alternatively, a fallback view could be chosen,
 	 * or the NoHandlerFoundException could be rethrown as-is.
 	 * @param ex the NoHandlerFoundException to be handled
 	 * @param request current HTTP request
@@ -459,10 +469,23 @@ protected ModelAndView handleBindException(BindException ex, HttpServletRequest
 	 * @throws IOException potentially thrown from response.sendError()
 	 * @since 4.0
 	 */
-	protected ModelAndView handleNoHandlerFoundException(NoHandlerFoundException ex, HttpServletRequest request,
-	                                           HttpServletResponse response, Object handler) throws IOException {
+	protected ModelAndView handleNoHandlerFoundException(NoHandlerFoundException ex,
+			HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {
+
 		response.sendError(HttpServletResponse.SC_NOT_FOUND);
 		return new ModelAndView();
 	}
 
+
+	/**
+	 * Invoked to send a server error. Sets the status to 500 and also sets the
+	 * request attribute "javax.servlet.error.exception" to the Exception.
+	 */
+	protected void sendServerError(Exception ex, HttpServletRequest request, HttpServletResponse response)
+			throws IOException {
+
+		request.setAttribute("javax.servlet.error.exception", ex);
+		response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+	}
+
 }