在ListAPIView中引发错误请求400异常

当用户未提供令牌或令牌无效时,Im试图引发400异常我的代码如下:

from rest_framework.exceptions import APIException, PermissionDenied


class MissingTokenException(APIException):
    status_code = 400
    default_detail = 'Your request does not contain token'
    default_code = 'no_token'


class InvalidTokenException(APIException):
    status_code = 400
    default_detail = 'Your request contain invalid token'
    default_code = 'invalid_token'

这是my views.py文件:

class ListProductsOfCategory(generics.ListAPIView):
    serializer_class = ProductSerializer
    lookup_url_kwarg = 'category_id'

    def dispatch(self, *args, **kwargs):
        token = self.request.META.get("HTTP_TOKEN", "")
        if not token:
            # here I wan to raise an error saying that no token provided.
           raise MissingTokenException
        if not UserAccess.objects.filter(accessToken=token).exists():
            # here I wan to raise an error saying that token provided is not valid.
           raise InvalidTokenException
        return super().dispatch(*args, **kwargs)

    def get_queryset(self):
        category_id = self.kwargs.get(self.lookup_url_kwarg)
        return Product.objects.filter(category_id=category_id)

如果有人可以帮助我新的django和python。