Play2.7 websocket 使用方法

play2.7x 中的websocket文档少得可怜、看来得适当完善一下子了、这里给大家记录一下一些使用过程吧。

使用

WebController.scala

Singleton
class SocketController @Inject()(cc: ControllerComponents)(implicit system: ActorSystem, ec: ExecutionContext, mat: Materializer)
  extends AbstractController(cc) {

  implicit val messageFlowTransformer = MessageFlowTransformer.jsonMessageFlowTransformer[JsValue, JsValue]
  implicit val format = org.json4s.DefaultFormats
  implicit val timeout: Timeout = 11.seconds

  def socket = WebSocket.accept[JsValue, JsValue] { request =>
    ActorFlow.actorRef { out =>
      Props(classOf[WebSocketActor], out)
    }
  }

}

WebSocketActor.scala

class WebSocketActor(client: ActorRef) extends Actor with ActorLogging {
def receive = {
	case msg:JsValue => 
	//do something
	client ! Json.object(
		"code" -> "success"
	)
}
}

routes配置

+ nocsrf
GET        /socket                                                      controllers.SocketController.socket

连接地扯

ws://localhost:9000/socket

重点

解析方式

implicit val messageFlowTransformer = MessageFlowTransformer.jsonMessageFlowTransformer[JsValue, JsValue]

里面还有4种解析规则

jsonMessageFlowTransformer //输入输出都是json数据
byteArrayMessageFlowTransformer //输入输出都是二进制数据
byteStringMessageFlowTransformer //输入输出都是ByteStrings的进制数据
stringMessageFlowTransformer //普通字符串消息

如果不满足自己的需求（定义安排上）
比如我需要输入的消息是json、但输出的数据是gzip压缩后的数据格式

implicit val jsonMessageFlowTransformer1: MessageFlowTransformer[JsValue, JsValue] = {
    def closeOnException[T](block: => T) =
      try {
        Left(block)
      } catch {
        case NonFatal(e) => Right(CloseMessage(Some(CloseCodes.Unacceptable), "Unable to parse json message"))
      }

    flow: Flow[JsValue, JsValue, _] => {
      AkkaStreams.bypassWith[Message, JsValue, Message](Flow[Message].collect {
        case BinaryMessage(data) =>
          closeOnException(Json.parse(data.iterator.asInputStream))
        case TextMessage(text) =>
          closeOnException(Json.parse(text))
      })(flow.map { json =>
        //TODO 输出改造、只要数据是实现了Message的接口即可
        BinaryMessage(ByteString.fromString(Json.stringify(json), "utf-8"))
      })
    }
  }