gistfile1.scala

val baseService = new Service[HttpRequest, HttpResponse] {
  def apply(request: HttpRequest) =
    Future(new DefaultHttpResponse(HTTP_1_1, OK))
}

val authorize = new RequireAuthorization(...)
val handleExceptions = new HandleExceptions(...)

val decoratedService: Service[HttpRequest, HttpResponse] =
  handleExceptions andThen authorize andThen baseService