akka http 下载 akka http testkit 中的编组答案

【问题标题】：akka http download marshalling in akka http testkitakka http 下载 akka http testkit 中的编组
【发布时间】：2020-03-16 14:35:12
【问题描述】：

我正在尝试在我的 akka http 测试中解组 csv 下载：

val bseq: immutable.Seq[ByteString] = Await.result(response.entity.dataBytes.runWith(Sink.seq), 20 seconds)
        val str = bseq.map(_.utf8String).mkString
        logger.debug(s"res:${str}")

但我明白了：

akka.http.scaladsl.marshalling.NoStrictlyCompatibleElementMarshallingAvailableException: None of the available marshallings (List(WithFixedContentType(application/octet-stream,<function0>))) directly match the ContentType requested by the top-level streamed entity (text/csv; charset=UTF-8). Please provide an implicit `Marshaller[akka.util.ByteString, HttpEntity]` that can render akka.util.ByteString as [text/csv; charset=UTF-8]
    at akka.http.scaladsl.marshalling.LowPriorityToResponseMarshallerImplicits$$anonfun$fromEntityStreamingSupportAndByteStringSourceMarshaller$1$$anonfun$apply$5$$anonfun$4$$anonfun$6$$anonfun$apply$7.apply(PredefinedToResponseMarshallers.scala:117)

如何在我的测试用例中解组 csv 文件？

【问题讨论】：

标签： scala akka-http

【解决方案1】：

问题出在路线方面。具体来说，csvMarshaller 不见了。

            import kantan.csv._
            import kantan.csv.ops._

            val src = StreamConverters
              .asOutputStream()
              .mapMaterializedValue { os =>
                Future {
                  try {
                    val ps = List(Person(0, "Nicolas", 38), Person(1, "Kazuma", 1), Person(2, "John", 18))

                    implicit val personEncoder: RowEncoder[Person] = RowEncoder.caseEncoder(0, 2, 1)(Person.unapply)

                    val writer = os.asCsvWriter[Person](rfc.withHeader("Column 1", "Column 2", "Column 3"))
                    ps.foreach { p =>
                      writer.write(p)
                    }
                    writer.close()
                  } catch {
                    case e: Throwable => logger.error("failed", e)
                  }
                }
              }
  implicit val csvStreaming: CsvEntityStreamingSupport = EntityStreamingSupport.csv()
// the missing csvMarshaller causes a runtime exception
            implicit val csvMarshaller: ToEntityMarshaller[ByteString] =
              Marshaller.withFixedContentType(ContentTypes.`text/csv(UTF-8)`) { bytes =>
                HttpEntity(ContentTypes.`text/csv(UTF-8)`, bytes)
              }
  complete(src)

【讨论】：