使用 Finagle Http 客户端下载文件

Question

我正在尝试从远程文件中获取一个字节数组。我创建了 AsyncStream 但不知道如何将其转换为正确的字节数组。

  val client: Service[http.Request, http.Response] =
    Http
      .client
      .withStreaming(enabled = true)
      .newService("www.scala-lang.org:80")

  val request = http.Request(http.Method.Get, "/docu/files/ScalaOverview.pdf")
  request.host = "scala-lang.org"
  val response: Future[http.Response] = client(request)

  def fromReader(reader: Reader): AsyncStream[Buf] =
    AsyncStream.fromFuture(reader.read(Int.MaxValue)).flatMap {
      case None => AsyncStream.empty
      case Some(a) => a +:: fromReader(reader)
    }

  val result: Array[Byte] =
    Await.result(response.flatMap {
      case resp =>
        fromReader(resp.reader) ??? // what to do?
    })

Answer 1

你不需要fromReader，AsyncStream已经有了。所以，你可以这样做：

val result: Future[Array[Byte]] = response
  .flatMap { resp => 
    AsyncStream.fromReader(resp.reader)
      .foldLeft(Buf.Empty){ _ concat _ }
      .map(Buf.ByteArray.Owned.extract)
  }

Answer 2

使用 scalaj 下载文件。

import scalaj.http._

val response: HttpResponse[String] = Http("http://foo.com/search").param("q","monkeys").asString

请参阅有关不同类型请求的文档 Get、Post 等

https://github.com/scalaj/scalaj-http

使用 Finagle Http 客户端下载文件

Download file with Finagle Http Client

scala

finagle