webapp2.py 文件源码

def default_dispatcher(self, request, response):
        """Dispatches a handler.

        :param request:
            A :class:`Request` instance.
        :param response:
            A :class:`Response` instance.
        :raises:
            ``exc.HTTPNotFound`` if no route matched or
            ``exc.HTTPMethodNotAllowed`` if a route matched but the HTTP
            method was not allowed.
        :returns:
            The returned value from the handler.
        """
        route, args, kwargs = rv = self.match(request)
        request.route, request.route_args, request.route_kwargs = rv

        if route.handler_adapter is None:
            handler = route.handler
            if isinstance(handler, six.string_types):
                if handler not in self.handlers:
                    self.handlers[handler] = handler = import_string(handler)
                else:
                    handler = self.handlers[handler]

            route.handler_adapter = self.adapt(handler)

        return route.handler_adapter(request, response)