Akka 如何使用Source.asSubscriber包装被动侦听器?
如何使用Akka 如何使用Source.asSubscriber包装被动侦听器?,akka,akka-stream,reactive-streams,Akka,Akka Stream,Reactive Streams,如何使用Source.asSubscriber包装被动侦听器?我不明白它的好处 我正在尝试为WebSocket创建Source[T]。这是我的密码: def createWsObservable(url: String, onStartAction: Option[WebSocket ⇒ Unit]): Source[WsMessage, KillSwitch] = Source.asSubscriber[WsMessage].mapMaterializedValue { subs: Sub
Source.asSubscriber
包装被动侦听器?我不明白它的好处
我正在尝试为WebSocket创建Source[T]
。这是我的密码:
def createWsObservable(url: String, onStartAction: Option[WebSocket ⇒ Unit]): Source[WsMessage, KillSwitch] =
Source.asSubscriber[WsMessage].mapMaterializedValue { subs: Subscriber[WsMessage] ⇒
val listener: WebSocketListener = new WebSocketListener() {
override def onOpen(ws: WebSocket): Unit =
subs.onNext(WsOpen(ws))
override def onClose(ws: WebSocket, code: Int, reason: String): Unit =
subs.onComplete()
override def onBinaryFrame(payload: Array[Byte], finalFragment: Boolean, rsv: Int): Unit =
// Doing bunch of stuff here
subs.onNext(...)
override def onTextFrame(payload: String, finalFragment: Boolean, rsv: Int): Unit =
// Doing bunch of stuff here
subs.onNext(...)
override def onError(t: Throwable): Unit =
subs.onError(t)
override def onPongFrame(payload: Array[Byte]): Unit = {
super.onPingFrame(payload)
}
}
val websocket =
asyncHttpClient
.prepareGet(url)
.execute(new WebSocketUpgradeHandler.Builder().addWebSocketListener(listener).build).get
new KillSwitch {
override def shutdown(): Unit = websocket.sendCloseFrame()
override def abort(ex: Throwable): Unit = websocket.sendCloseFrame()
}
}
在第一个事件中,我得到异常:
java.lang.IllegalStateException: spec violation: onNext was signaled from upstream without demand
at akka.stream.impl.VirtualProcessor.rec$5(StreamLayout.scala:239)
at akka.stream.impl.VirtualProcessor.onNext(StreamLayout.scala:243)
at ingestion.NettyClientWrapper$$anon$2.onOpen(NettyClientWrapper.scala:55)
也许
Source.asSubscriber
对我来说不是个好选择?如何将reactivestreams订阅服务器包装到akka的源代码中?如果您有一个发布者
,希望将其公开为源代码
,则可以使用Source.fromPublisher
在您的案例中,第一个问题是如何从AHC获得发布者。我不知道AHC,但从我阅读的内容来看,不清楚您是否可以同时拥有反应流支持(这要求您将
streamdasynchandler
传递给execute
方法)和WebSocket支持(这需要WebSocketUpgradeHandler
)。我希望有可能将它们组合在一起。我最终使用了Source.actorRef
和KillSwitch
def createWsObservable(url: String, onStartAction: WebSocket ⇒ Option[KillSwitch] = _ ⇒ None, bufferSize: Int = 32): Source[WsMessage, KillSwitch] = {
val actorSource = Source.actorRef[WsMessage](bufferSize, OverflowStrategy.fail)
actorSource.mapMaterializedValue { actor ⇒
val listener: WebSocketListener = new WebSocketListener() {
override def onOpen(ws: WebSocket): Unit =
actor ! ...
override def onClose(ws: WebSocket, code: Int, reason: String): Unit =
actor ! akka.actor.Status.Success(code)
override def onBinaryFrame(payload: Array[Byte], finalFragment: Boolean, rsv: Int): Unit =
actor ! ...
override def onTextFrame(payload: String, finalFragment: Boolean, rsv: Int): Unit =
actor ! ...
override def onError(t: Throwable): Unit =
actor ! akka.actor.Status.Failure(t)
}
val websocket =
asyncHttpClient
.prepareGet(url)
.execute(new WebSocketUpgradeHandler.Builder().addWebSocketListener(listener).build).get
// Use Pong reply as indication that we've connected to the server
val p = Promise[Void]()
websocket.sendPingFrame().addListener(p)
val onStartKillSwitchFut = p.future.map(_ ⇒ onStartAction(websocket))
new KillSwitch {
override def shutdown(): Unit = {
onStartKillSwitchFut.map(_.foreach(_.shutdown()))
websocket.sendCloseFrame()
}
override def abort(ex: Throwable): Unit = {
onStartKillSwitchFut.map(_.foreach(_.abort(ex)))
websocket.sendCloseFrame()
}
}
}
}
```override def onPongFrame(payload:Array[Byte]):Unit={super.onPingFrame(payload)}``看起来像是打字错误,也许这就是原因?