最近使用spring mvc开发一个web系统，发现在controller里发生未捕获异常时不出日志。

/**	 * Initialize the strategy objects that this servlet uses.	 * 
May be overridden in subclasses in order to initialize	 * further strategy objects.	 */	protected void initStrategies(ApplicationContext context) {		initMultipartResolver(context);		initLocaleResolver(context);		initThemeResolver(context);		initHandlerMappings(context);		initHandlerAdapters(context);// 初始化异常处理支持器		initHandlerExceptionResolvers(context);		initRequestToViewNameTranslator(context);		initViewResolvers(context);	}// 进入初始化处理方法，具体内容就不贴了，主要是先到上下文中搜寻我们自己定义的ExceptionResolvers，如果没有自定义的resolvers，从默认配置中读取。private void initHandlerExceptionResolvers(ApplicationContext context)// 从默认策略中取得默认配置，从DispatcherServlet.properties文件中取得相关的配置策略，但是在spring2.5的mvc jar包中properties文件中没有HandlerExceptionResolver的默认配置，返回一个EmptyList给handlerExceptionResolversprotected List getDefaultStrategies(ApplicationContext context, Class strategyInterface)

// 从dispatch方法中看到，系统对请求进行具体的逻辑处理部分被catch住了一次exception，然后会使用servlet持有的ExceptionResolver进行处理protected void doDispatch(HttpServletRequest request, HttpServletResponse response) throws Exception {		HttpServletRequest processedRequest = request;		HandlerExecutionChain mappedHandler = null;		int interceptorIndex = -1;		// Expose current LocaleResolver and request as LocaleContext.		LocaleContext previousLocaleContext = LocaleContextHolder.getLocaleContext();		LocaleContextHolder.setLocaleContext(buildLocaleContext(request), this.threadContextInheritable);		// Expose current RequestAttributes to current thread.		RequestAttributes previousRequestAttributes = RequestContextHolder.getRequestAttributes();		ServletRequestAttributes requestAttributes = new ServletRequestAttributes(request);		RequestContextHolder.setRequestAttributes(requestAttributes, this.threadContextInheritable);		if (logger.isTraceEnabled()) {			logger.trace("Bound request context to thread: " + request);		}				try {			ModelAndView mv = null;			boolean errorView = false;			try {				processedRequest = checkMultipart(request);				// Determine handler for the current request.				mappedHandler = getHandler(processedRequest, false);				if (mappedHandler == null || mappedHandler.getHandler() == null) {					noHandlerFound(processedRequest, response);					return;				}				// Apply preHandle methods of registered interceptors.				HandlerInterceptor[] interceptors = mappedHandler.getInterceptors();				if (interceptors != null) {					for (int i = 0; i < interceptors.length; i++) {						HandlerInterceptor interceptor = interceptors[i];						if (!interceptor.preHandle(processedRequest, response, mappedHandler.getHandler())) {							triggerAfterCompletion(mappedHandler, interceptorIndex, processedRequest, response, null);							return;						}						interceptorIndex = i;					}				}				// Actually invoke the handler.				HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());				mv = ha.handle(processedRequest, response, mappedHandler.getHandler());				// Do we need view name translation?				if (mv != null && !mv.hasView()) {					mv.setViewName(getDefaultViewName(request));				}				// Apply postHandle methods of registered interceptors.				if (interceptors != null) {					for (int i = interceptors.length - 1; i >= 0; i--) {						HandlerInterceptor interceptor = interceptors[i];						interceptor.postHandle(processedRequest, response, mappedHandler.getHandler(), mv);					}				}			}			catch (ModelAndViewDefiningException ex) {				logger.debug("ModelAndViewDefiningException encountered", ex);				mv = ex.getModelAndView();			}// 这里catch住controller抛出的异常，使用持有的ExceptionResolver处理，当没有配置自己的处理器时，程序会将异常继续往上抛出，最终交给我们的容器处理			catch (Exception ex) {				Object handler = (mappedHandler != null ? mappedHandler.getHandler() : null);				mv = processHandlerException(processedRequest, response, handler, ex);				errorView = (mv != null);			}			// Did the handler return a view to render?			if (mv != null && !mv.wasCleared()) {				render(mv, processedRequest, response);				if (errorView) {					WebUtils.clearErrorRequestAttributes(request);				}			}			else {				if (logger.isDebugEnabled()) {					logger.debug("Null ModelAndView returned to DispatcherServlet with name '" +							getServletName() + "': assuming HandlerAdapter completed request handling");				}			}			// Trigger after-completion for successful outcome.			triggerAfterCompletion(mappedHandler, interceptorIndex, processedRequest, response, null);		}// 当没有配置ExceptionResolver时，异常将到达这里，最终抛出		catch (Exception ex) {			// Trigger after-completion for thrown exception.			triggerAfterCompletion(mappedHandler, interceptorIndex, processedRequest, response, ex);			throw ex;		}		catch (Error err) {			ServletException ex = new NestedServletException("Handler processing failed", err);			// Trigger after-completion for thrown exception.			triggerAfterCompletion(mappedHandler, interceptorIndex, processedRequest, response, ex);			throw ex;		}		finally {			// Clean up any resources used by a multipart request.			if (processedRequest != request) {				cleanupMultipart(processedRequest);			}			// Reset thread-bound context.			RequestContextHolder.setRequestAttributes(previousRequestAttributes, this.threadContextInheritable);			LocaleContextHolder.setLocaleContext(previousLocaleContext, this.threadContextInheritable);			// Clear request attributes.			requestAttributes.requestCompleted();			if (logger.isTraceEnabled()) {				logger.trace("Cleared thread-bound request context: " + request);			}		}	}