/**
  * Handle error throws in future, return default value on error
  */
def recover(): Unit = {
  val f: Future[String] = downloadBlob("ftp://blobs/8671").recover {
    case e =>
      println(s"fail download, ${e.getMessage}")
      "empty blob"
  }
  println(Await.result(f, 10.seconds))
}

/*
 * output
fail download, invalid uri
empty blob
*/