Scala Akka Streams项目无法编译，“value~＆gt;不是akka.streams.Outlet [In]的成员”

Question

我在Scala项目中使用Akka Streams API，使用SBT插件在Intellij IDEA中工作。我有一个工作池流程，如下所述：https://doc.akka.io/docs/akka/current/scala/stream/stream-cookbook.html。这是我的代码：

"aggregations": {
    "employees_per_month": {
        "buckets": [
            {
                "key_as_string": "2017-01-01",
                "doc_count": 1
            },
            {
                "key_as_string": "2017-02-01",
                "doc_count": 2
            },
            {
                "key_as_string": "2017-03-01",
                "doc_count": 2
            },
            {
                "key_as_string": "2017-04-01",
                "doc_count": 3
            },
            {
                "key_as_string": "2017-05-01",
                "doc_count": 3
            },
            {
                "key_as_string": "2017-06-01",
                "doc_count": 2
            }
        ]
    }
}

由于某种原因，项目现在无法编译，出现此错误：package streams import akka.NotUsed import akka.stream.scaladsl.{Balance, Flow, GraphDSL, Merge} import akka.stream.{FlowShape, Graph} object WorkerPoolFlow { def apply[In, Out]( worker: Flow[In, Out, Any], workerCount: Int): Graph[FlowShape[In, Out], NotUsed] = { GraphDSL.create() { implicit b => val balance = b.add(Balance[In](workerCount, waitForAllDownstreams = true)) val merge = b.add(Merge[Out](workerCount)) for (i <- 0 until workerCount) balance.out(i) ~> worker.async ~> merge.in(i) FlowShape( balance.in, merge.out) } } } 。

直到今天才编好。我所知道的唯一变化是安装Scala linter插件value ~> is not a member of akka.stream.Outlet[In]，并在scalafmt中导入一些新库。这是我的build.sbt：

build.sbt

我尝试重新加载SBT，从IDEA之外的SBT构建，删除并重新添加依赖项，以及清理项目，没有运气。

Answer 1

导入GraphDSL.Implicits._：

object WorkerPoolFlow {
  def apply[In, Out](
    worker: Flow[In, Out, Any],
    workerCount: Int):
  Graph[FlowShape[In, Out], NotUsed] = {
    import GraphDSL.Implicits._

    GraphDSL.create() { implicit b =>
      ...
    }
  }
}