检测商品库存#

{
    "code": 200,
    "message": "success",
    "data": {
        "total": 299,
        "can_buy": true
    }
}

{
    "code": 200,
    "message": "库存数量只有288个，您最多只能购买288个",
    "data": {
        "total": 288,
        "can_buy": false
    }
}