Question

我已经按照Scala Play和Akka演员创建Web套接字的示例：

https://www.playframework.com/documentation/2.5.x/ScalaWebSockets#Handling-WebSockets-with-Akka-Streams-and-actors

恢复时，控制器：

import play.api.mvc._
import play.api.libs.streams._

class Controller1 @Inject() (implicit system: ActorSystem, materializer: Materializer) {

  def socket = WebSocket.accept[String, String] { request =>
    ActorFlow.actorRef(out => MyWebSocketActor.props(out))
  }

演员：

import akka.actor._

object MyWebSocketActor {
  def props(out: ActorRef) = Props(new MyWebSocketActor(out))
}

class MyWebSocketActor(out: ActorRef) extends Actor {
  def receive = {
    case msg: String =>
      out ! ("I received your message: " + msg)
  }
}

创建的actor（每个websocket连接一个）是/ user actor的子级。我创建了3个连接，创建的actor是：

/用户/ $ B
/用户/ $ C
/用户/ $ d

我想改变演员＆＃39;名称基于Web套接字消息的字段。我怎么能这样做？。

Answer 1

您可以按如下方式设置actor的名称：

创建一个文件BetterActorFlow.scala

package your.package

import akka.actor._
import akka.stream.scaladsl.{Keep, Sink, Source, Flow}
import akka.stream.{Materializer, OverflowStrategy}

object BetterActorFlow {

  def actorRef[In, Out](props: ActorRef => Props, bufferSize: Int = 16, overflowStrategy: OverflowStrategy = OverflowStrategy.dropNew, maybeName: Option[String] = None)(implicit factory: ActorRefFactory, mat: Materializer): Flow[In, Out, _] = {

    val (outActor, publisher) = Source.actorRef[Out](bufferSize, overflowStrategy)
                        .toMat(Sink.asPublisher(false))(Keep.both).run()

    def flowActorProps: Props = {
      Props(new Actor {
        val flowActor = context.watch(context.actorOf(props(outActor), "flowActor"))

        def receive = {
          case Status.Success(_) | Status.Failure(_) => flowActor ! PoisonPill
          case Terminated(_) => context.stop(self)
          case other => flowActor ! other
        }

        override def supervisorStrategy = OneForOneStrategy() { case _ => SupervisorStrategy.Stop }
      })
    }

    def actorRefForSink =
      maybeName.fold(factory.actorOf(flowActorProps)) { name => factory.actorOf(flowActorProps, name) }

    Flow.fromSinkAndSource(Sink.actorRef(actorRefForSink, Status.Success(())), Source.fromPublisher(publisher))

  }
}

使用BetterActorFlow而不是ActorFlow：

BetterActorFlow.actorRef(out =>
  ChatActor.props(out), 16, OverflowStrategy.dropNew, Some("alicebob"))

这对我有用。创建的actor位于user/alicebob（使用此context.system.actorSelection("user/alicebob")）

Answer 2

根据ActorFlow的源代码，目前无法确定为连接产生的实际actor的名称（第38行）：

Sink.actorRef(factory.actorOf(Props(new Actor { ... }) /*, name parameter is omitted */)

但是，ActorFlow.actorRef接受隐式ActorRefFactory，在代码中的所有情况下均为implicit system: ActorSystem。我们知道，有两个最常见的ActorRefFactories：ActorSystem和ActorContext。您可以修改代码，以便每次接受连接时，另一个虚拟演员将使用您的首选名称（例如myActor1）生成，并将此新演员的context传递给{ {1}}而是。作为回报，连接的参与者将按如下命名：

/用户/ myActor1 / $一个
/用户/ myActor2 / $一个
等

玩Scala Akka WebSockets改变演员路径

2 个答案: