code: private @Nullable
  	View resolveViewName(String viewName, Locale locale) throws Exception {
  		for (ViewResolver r : resolvers) {
  			View view = r.resolveViewName(viewName, locale);
  			if (view != null) {
  				return view;
  			}
  		}
  		return null;
  	}
docs: "cannot resolve view named:"+viewName);