Play Framework/Scala example source code file (JavaWebSocket.scala)

This example Play Framework source code file (JavaWebSocket.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Play Framework (and Scala) source code examples by using tags.

All credit for the original source code belongs to Play Framework; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Play Framework tags/keywords

a, api, array, concurrent, core, javahelpers, javawebsocket, jpromise, jsonnode, jwebsocket, mvc, play, play framework, right, string, websocket

The JavaWebSocket.scala Play Framework example source code

/*
 * Copyright (C) 2009-2013 Typesafe Inc. <http://www.typesafe.com>
 */
package play.core.j

import play.api.mvc._
import play.mvc.Http.{ Context => JContext }
import play.mvc.{ WebSocket => JWebSocket }
import play.libs.F.{ Promise => JPromise }
import scala.collection.JavaConverters._

import scala.concurrent.Future
import com.fasterxml.jackson.databind.JsonNode
import play.core.actors.WebSocketActor._
import play.api.libs.concurrent.Akka

import play.api.Play.current
import play.core.Execution.Implicits.internalContext
import scala.reflect.ClassTag

/**
 * handles a scala websocket in a Java Context
 */
object JavaWebSocket extends JavaHelpers {

  def webSocketWrapper[A](retrieveWebSocket: => Future[JWebSocket[A]])(implicit frameFormatter: WebSocket.FrameFormatter[A], mt: ClassTag[A]): WebSocket[A, A] = WebSocket[A, A] { request =>

    val javaContext = createJavaContext(request)

    val javaWebSocket = try {
      JContext.current.set(javaContext)
      retrieveWebSocket
    } finally {
      JContext.current.remove()
    }

    javaWebSocket.map { jws =>
      val reject = Option(jws.rejectWith())
      reject.map { result =>

        Left(createResult(javaContext, result))

      } getOrElse {

        Right((in, out) => {

          if (jws.isActor) {

            WebSocketsExtension(Akka.system).actor !
              WebSocketsActor.Connect(request.id, in, out, actorRef => jws.actorProps(actorRef))

          } else {

            import play.api.libs.iteratee._

            val (enumerator, channel) = Concurrent.broadcast[A]

            val socketOut = new play.mvc.WebSocket.Out[A] {
              def write(frame: A) {
                channel.push(frame)
              }
              def close() {
                channel.eofAndEnd()
              }
            }

            val socketIn = new play.mvc.WebSocket.In[A]

            enumerator |>> out

            jws.onReady(socketIn, socketOut)

            in |>> {
              Iteratee.foreach[A](msg => socketIn.callbacks.asScala.foreach(_.invoke(msg))).map { _ =>
                socketIn.closeCallbacks.asScala.foreach(_.invoke())
              }
            }
          }
        })
      }
    }
  }

  // -- Bytes

  def ofBytes(retrieveWebSocket: => JWebSocket[Array[Byte]]): WebSocket[Array[Byte], Array[Byte]] =
    webSocketWrapper[Array[Byte]](Future.successful(retrieveWebSocket))

  def promiseOfBytes(retrieveWebSocket: => JPromise[JWebSocket[Array[Byte]]]): WebSocket[Array[Byte], Array[Byte]] =
    webSocketWrapper[Array[Byte]](retrieveWebSocket.wrapped())

  // -- String

  def ofString(retrieveWebSocket: => JWebSocket[String]): WebSocket[String, String] =
    webSocketWrapper[String](Future.successful(retrieveWebSocket))

  def promiseOfString(retrieveWebSocket: => JPromise[JWebSocket[String]]): WebSocket[String, String] =
    webSocketWrapper[String](retrieveWebSocket.wrapped())

  // -- Json (JsonNode)

  implicit val jsonFrame = WebSocket.FrameFormatter.stringFrame.transform(
    play.libs.Json.stringify, play.libs.Json.parse
  )

  def ofJson(retrieveWebSocket: => JWebSocket[JsonNode]): WebSocket[JsonNode, JsonNode] =
    webSocketWrapper[JsonNode](Future.successful(retrieveWebSocket))

  def promiseOfJson(retrieveWebSocket: => JPromise[JWebSocket[JsonNode]]): WebSocket[JsonNode, JsonNode] =
    webSocketWrapper[JsonNode](retrieveWebSocket.wrapped())
}