springMVC 之 HandlerMethodArgumentResolver使用

@Override
	public Object resolveArgument(MethodParameter parameter, ModelAndViewContainer mavContainer,
			NativeWebRequest webRequest, WebDataBinderFactory binderFactory) throws Exception {

		Class<?> paramType = parameter.getParameterType();
		if (WebRequest.class.isAssignableFrom(paramType)) {
			return webRequest;
		}

		HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
		if (ServletRequest.class.isAssignableFrom(paramType) || MultipartRequest.class.isAssignableFrom(paramType)) {
			Object nativeRequest = webRequest.getNativeRequest(paramType);
			if (nativeRequest == null) {
				throw new IllegalStateException(
						"Current request is not of type [" + paramType.getName() + "]: " + request);
			}
			return nativeRequest;
		}
		else if (HttpSession.class.isAssignableFrom(paramType)) {
			return request.getSession();
		}
		else if (HttpMethod.class == paramType) {
			return ((ServletWebRequest) webRequest).getHttpMethod();
		}
		else if (Principal.class.isAssignableFrom(paramType)) {
			return request.getUserPrincipal();
		}
		else if (Locale.class == paramType) {
			return RequestContextUtils.getLocale(request);
		}
		else if (TimeZone.class == paramType) {
			TimeZone timeZone = RequestContextUtils.getTimeZone(request);
			return (timeZone != null ? timeZone : TimeZone.getDefault());
		}
		else if ("java.time.ZoneId".equals(paramType.getName())) {
			return ZoneIdResolver.resolveZoneId(request);
		}
		else if (InputStream.class.isAssignableFrom(paramType)) {
			return request.getInputStream();
		}
		else if (Reader.class.isAssignableFrom(paramType)) {
			return request.getReader();
		}
		else {
			// should never happen...
			throw new UnsupportedOperationException(
					"Unknown parameter type: " + paramType + " in method: " + parameter.getMethod());
		}
	}