django ALLOWED_HOSTS无法正常工作

仅对于想要过滤引荐来源网址而不是IP地址的任何人，我们可以使用以下中间件：

from django.conf import settingsfrom django import httpclass AllowHostsMiddleware(object):    def process_request(self, request):        referer_url = request.meta.get('HTTP_REFERER','')        if referer_url.startswith(settings.ALLOWED_REFERER_URL): return None        return http.HttpResponseForbidden('<h1>Forbidden</h1>')