spring mvc异常吃掉的问题

今天发现spring mvc把一个view参数匹配异常（org.springframework.web.bind.MissingServletRequestParameterException: Required String parameter 'tagSet' is not present）吃掉了：

 

1.通过debug发现Exception

 

2.异常被processHanderException方法处理，但直接返回Null，没有打印异常。

 

 

 

问题查找

通过debug发现是通过org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver.handleMissingServletRequestParameter()

处理的：

protected ModelAndView doResolveException(HttpServletRequest request, HttpServletResponse response,
			Object handler, Exception ex) {

		try {
			if (ex instanceof NoSuchRequestHandlingMethodException) {
				return handleNoSuchRequestHandlingMethod((NoSuchRequestHandlingMethodException) ex, request, response,
						handler);
			}
			else if (ex instanceof HttpRequestMethodNotSupportedException) {
				return handleHttpRequestMethodNotSupported((HttpRequestMethodNotSupportedException) ex, request,
						response, handler);
			}
			else if (ex instanceof HttpMediaTypeNotSupportedException) {
				return handleHttpMediaTypeNotSupported((HttpMediaTypeNotSupportedException) ex, request, response,
						handler);
			}
			else if (ex instanceof HttpMediaTypeNotAcceptableException) {
				return handleHttpMediaTypeNotAcceptable((HttpMediaTypeNotAcceptableException) ex, request, response,
						handler);
			}
			else if (ex instanceof MissingServletRequestParameterException) {
				return handleMissingServletRequestParameter((MissingServletRequestParameterException) ex, request,
						response, handler);
			}
			else if (ex instanceof ServletRequestBindingException) {
				return handleServletRequestBindingException((ServletRequestBindingException) ex, request, response,
						handler);
			}
			else if (ex instanceof ConversionNotSupportedException) {
				return handleConversionNotSupported((ConversionNotSupportedException) ex, request, response, handler);
			}
			else if (ex instanceof TypeMismatchException) {
				return handleTypeMismatch((TypeMismatchException) ex, request, response, handler);
			}
			else if (ex instanceof HttpMessageNotReadableException) {
				return handleHttpMessageNotReadable((HttpMessageNotReadableException) ex, request, response, handler);
			}
			else if (ex instanceof HttpMessageNotWritableException) {
				return handleHttpMessageNotWritable((HttpMessageNotWritableException) ex, request, response, handler);
			}
			else if (ex instanceof MethodArgumentNotValidException) {
				return handleMethodArgumentNotValidException((MethodArgumentNotValidException) ex, request, response, handler);
			}
			else if (ex instanceof MissingServletRequestPartException) {
				return handleMissingServletRequestPartException((MissingServletRequestPartException) ex, request, response, handler);
			}
		}
		catch (Exception handlerException) {
			logger.warn("Handling of [" + ex.getClass().getName() + "] resulted in Exception", handlerException);
		}
		return null;
	}

 

	protected ModelAndView handleMissingServletRequestParameter(MissingServletRequestParameterException ex,
			HttpServletRequest request, HttpServletResponse response, Object handler) throws IOException {

		response.sendError(HttpServletResponse.SC_BAD_REQUEST);
		return new ModelAndView();
	}

那么DefaultHandlerExceptionResolver怎么被初始化的？ 发现是在DispatcherServlet.initHandlerExceptionResolvers()负责初始化。

private void initHandlerExceptionResolvers(ApplicationContext context) {
		this.handlerExceptionResolvers = null;

		if (this.detectAllHandlerExceptionResolvers) {
			// Find all HandlerExceptionResolvers in the ApplicationContext, including ancestor contexts.
			Map<String, HandlerExceptionResolver> matchingBeans = BeanFactoryUtils
					.beansOfTypeIncludingAncestors(context, HandlerExceptionResolver.class, true, false);
			if (!matchingBeans.isEmpty()) {
				this.handlerExceptionResolvers = new ArrayList<HandlerExceptionResolver>(matchingBeans.values());
				// We keep HandlerExceptionResolvers in sorted order.
				OrderComparator.sort(this.handlerExceptionResolvers);
			}
		}
		else {
			try {
				HandlerExceptionResolver her =
						context.getBean(HANDLER_EXCEPTION_RESOLVER_BEAN_NAME, HandlerExceptionResolver.class);
				this.handlerExceptionResolvers = Collections.singletonList(her);
			}
			catch (NoSuchBeanDefinitionException ex) {
				// Ignore, no HandlerExceptionResolver is fine too.
			}
		}

		// Ensure we have at least some HandlerExceptionResolvers, by registering
		// default HandlerExceptionResolvers if no other resolvers are found.
		if (this.handlerExceptionResolvers == null) {
			this.handlerExceptionResolvers = getDefaultStrategies(context, HandlerExceptionResolver.class);
			if (logger.isDebugEnabled()) {
				logger.debug("No HandlerExceptionResolvers found in servlet '" + getServletName() + "': using default");
			}
		}
	}

 那么我们只需要实现一个继承于DefaultHandlerExceptionResolver的类，然后会被spring通过BeanFactoryUtils.beansOfTypeIncludingAncestors(context, HandlerExceptionResolver.class, true, false);加载