scala future 動態並行異步 ;promise jobs join item scala dynamic

在node 裏面一招 Promise.all 就搞定, scala語言這裏稍微有點不同

    object Fiddle {
      val f1 = Future {
        throw new Throwable("baaa") // emulating a future that bumped into an exception
      }
    
      val f2 = Future {
        Thread.sleep(3000L) // emulating a future that takes a bit longer to complete
        2
      }
    
      val lf = List(f1, f2) // in the general case, this would be a dynamically sized list
    
      val seq = Future.sequence(lf) 
      import scala.concurrent.duration._
      Await.result(seq, Duration.Inf) 
    }

這樣就很好的解決了異步函數動態並行執行的場景 後期的結果值處理有多種方法 await 是不那麼優雅的方法,但是比較頂用

implicit val ec = ExecutionContext.global

val f1 = Future {
  Try {
    throw new Throwable("kaboom")
  }
}

val f2 = Future {
  Try {
    Thread.sleep(1000L)
    2
  }
}

Await.result(
  Future.sequence(Seq(f1, f2)), Duration("2 sec")
) foreach {
  case Success(res) => println(s"Success. $res")
  case Failure(e)   => println(s"Failure. ${e.getMessage}")
}