@PostMapping("/create")
    public ResultVo<Map<String, String>> craete(@Valid OrderForm orderForm, BindingResult bindingResult)
    {
        if (bindingResult.hasErrors())
        {
            log.error("【创建订单】参数不正确， orderForm = {}",orderForm);
            throw new SellException(ResultEnum.PARAM_ERROR.getCode(), bindingResult.getFieldError().getDefaultMessage());
        }
        OrderDto orderDto = OrderForm2OrderDtoConverter.convert(orderForm);
        if (CollectionUtils.isEmpty(orderDto.getOrderDetailList()))
        {
            log.error("【创建订单】 购物车不能为空, orderdto = {}", orderDto);
            throw new SellException(ResultEnum.PRODUCT_STOCK_ERROR);
        }
        OrderDto createResult = orderService.create(orderDto);
        Map<String, String> map = new HashMap<>();
        map.put("orderid", createResult.getOrderId());

        return ResultVoUtil.success(map);
    }

如图，是师兄给出的代码，如果调整返回值

@PostMapping("/create")
    public Map<String, String> craete(@Valid OrderForm orderForm, BindingResult bindingResult)
    {
        if (bindingResult.hasErrors())
        {
            log.error("【创建订单】参数不正确， orderForm = {}",orderForm);
            throw new SellException(ResultEnum.PARAM_ERROR.getCode(), bindingResult.getFieldError().getDefaultMessage());
        }
        OrderDto orderDto = OrderForm2OrderDtoConverter.convert(orderForm);
        if (CollectionUtils.isEmpty(orderDto.getOrderDetailList()))
        {
            log.error("【创建订单】 购物车不能为空, orderdto = {}", orderDto);
            throw new SellException(ResultEnum.PRODUCT_STOCK_ERROR);
        }
        OrderDto createResult = orderService.create(orderDto);
        Map<String, String> map = new HashMap<>();
        map.put("orderid", createResult.getOrderId());

        return map;
    }

前端页面并不能渲染出我们想要的结果，请问这是个什么原理呢？