我正在创建一个Akka Http路由，该路由使用WebSocket将无限量的TextMessage流传输到客户端。我忽略了来自客户端的消息，并发回了消息流。

为简单起见，我已经创建了一个简化的代码版本。问题在于，在客户端发出初始请求后，客户端未收到任何消息。

// Using the Source.queue component to "inject" data into the Source
val queueSource: Source[TextMessage,SourceQueueWithComplete[String]] = 
  Source
    .queue[String](1024,OverflowStrategy.backpressure)
    .map(quoteStr => TextMessage(quoteStr.toString))

// This simulates messages received from an external system being 
// feed into the Source
Future {
  val queue = queueSource.preMaterialize()._1
  val rng = Random
  while(true) {
    Thread.sleep(500)
    queue.offer(rng.nextString(20))
  }
}

val route =  
  path("api" / "stream") {
    handleWebSocketMessages(
      Flow.fromSinkAndSource(
        Sink.ignore,queueSource
      )
    )
  }

Http().bindAndHandle(route,"0.0.0.0",8081)

如果我将queueSource替换为Source(1 to 10).throttle(2,1 second，一切正常。