spring MVC 中获取request

spring MVC中如何获取request 呢?
有如下方式:
方式一:在action中注入request
直接在action的参数中增加HttpServletRequest request
例如

/***
     * 返回json
     * @param id
     * @param roleLevel
     * @param model
     * @param request
     * @param targetView
     * @return
     * @throws SecurityException
     * @throws NoSuchFieldException
     * @throws IllegalArgumentException
     * @throws IllegalAccessException
     */
    @ResponseBody
    @RequestMapping(value = "/{id}/update/json",method=RequestMethod.POST) 
    public String json_update(@PathVariable int id,T roleLevel, Model model,HttpServletRequest request,String targetView) throws SecurityException, NoSuchFieldException, IllegalArgumentException, IllegalAccessException {
        boolean success= updateCommon(id, roleLevel, model, request);
        Map map=new HashMap();
        if(!success){
            map.put(Constant2.LOGIN_RESULT_KEY, false);
            map.put(Constant2.RESPONSE_KEY_ERROR_MESSAGE, "未找到记录,id:"+id);
            return HWUtils.getJsonP(map);
        }
        return Constant2.RESPONSE_RIGHT_RESULT;

    }

方式二:使用RequestContextHolder
HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();

protected GenericDao getDao() {
        if(this.dao==null){
            System.out.println("请先执行init(request)");
            HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
            init(request);
        }
        return this.dao;
    }