Akka HTTP设置自定义内容类型响应头

Question

我需要设置Content-Type = "application/vxml"，

尝试了以下代码，但无效。

  val contentTypeHeader   = RawHeader("Content-Type", "application/vxml")
  val cacheControlHeader  = RawHeader("Cache-Control", "public, max-age=3600")
  val acceptRangesHeader  = RawHeader("Accept-Ranges", "bytes")
  val vxmlResponseHeaders = Seq(contentTypeHeader, cacheControlHeader, acceptRangesHeader)

  complete {
    actorResponseFuture map { response =>
      HttpResponse(StatusCodes.OK,
                   headers = vxmlResponseHeaders,
                   entity = HttpEntity(handleResponse(response, uri.toString())))
      }
  }

但是它会引发以下错误，

2020-04-24 14:24:00.722  WARN  [ccc-vxml-activities-akka.actor.default-dispatcher-14] akka.actor.ActorSystemImpl - Explicitly set HTTP header 'Content-Type: application/vxml' is ignored, illegal RawHeader

我以前使用以下代码将Content-Type设置为text/xml(UTF-8)，但是由于application/vxml中没有ContentTypes，所以我不能使用这种方法。

complete {
  actorResponseFuture map { response =>
    HttpResponse(StatusCodes.OK,
                 entity = HttpEntity(ContentTypes.`text/xml(UTF-8)`,
                                     handleResponse(response, uri.toString())))
  }
} 

任何指针都会有所帮助。