I am trying to implement websocket using play 2.3.x. I want server to be able to send message to one client or all the client.
Here is my controller code:
object Client extends Controller {
def socket(guid: String) = WebSocket.acceptWithActor[String, String] { request =>
out => ClientWebSocketActor.props(guid, out)
}
And below is my Actor code:
object ClientWebSocketActor {
def props(uuid: String, out: ActorRef) = Props(new ClientWebSocketActor(uuid, out))
}
class ClientWebSocketActor(uuid: String, out: ActorRef) extends Actor {
val (enumerator, channel) = Concurrent.broadcast[String]
var clients = Map[String, (Enumerator[String], Channel[String])]()
import ClientWebSocketActor._
def receive = {
case msg: String =>
println(msg)
val (enumerator, channel1) = Concurrent.broadcast[String]
clients += ((uuid, (enumerator, channel1)))
println(clients)
channel1 push "Message is " + msg
}
}
Issue I am facing:
channel1 push doesn't reply to the client that sent the message
In clients map all the clients are not added
channel push msg doesn't work to send message to all clients
Any help would be greatly appreciated.
Related
i am new to akka websockets and learning akka client side websockets https://doc.akka.io/docs/akka-http/current/client-side/websocket-support.html
i am using websockets for my webrtc janus server for that i have URL and i need to send many messages to it and receive a different response each time and send further messages based on that response here i am confused how can we do that by looking at the example code i think i need to repeat the below code every time i need to send a message to the server but it does not seemed correct si what is the right approach?
example in my case
websocket server is running at
ws://0.0.0.0:8188
first i will send a message to the server for initiating the sessionID
request# 1
{
"janus" : "create",
"transaction" : "<random alphanumeric string>"
}
the server will respond with the session id
response #1
{
"janus": "success",
"session_id": 2630959283560140,
"transaction": "asqeasd4as3d4asdasddas",
"data": {
"id": 4574061985075210
}
}
then based on id 4574061985075210 i will send another message and receive further info
request # 02 {
}
response # 02 {
}
----
how can i achieve this with akka client side websockets
here is my code
import akka.http.scaladsl.model.ws._
import scala.concurrent.Future
object WebSocketClientFlow {
def main(args: Array[String]) = {
implicit val system = ActorSystem()
implicit val materializer = ActorMaterializer()
import system.dispatcher
val incoming: Sink[Message, Future[Done]] =
Sink.foreach[Message] {
case message: TextMessage.Strict =>
println(message.text)
//suppose here based on the server response i need to send another message to the server and so on do i need to repeat this same code here again ?????
}
val outgoing = Source.single(TextMessage("hello world!"))
val webSocketFlow = Http().webSocketClientFlow(WebSocketRequest("ws://echo.websocket.org"))
val (upgradeResponse, closed) =
outgoing
.viaMat(webSocketFlow)(Keep.right) // keep the materialized Future[WebSocketUpgradeResponse]
.toMat(incoming)(Keep.both) // also keep the Future[Done]
.run()
val connected = upgradeResponse.flatMap { upgrade =>
if (upgrade.response.status == StatusCodes.SwitchingProtocols) {
Future.successful(Done)
} else {
throw new RuntimeException(s"Connection failed: ${upgrade.response.status}")
}
}
connected.onComplete(println)
closed.foreach(_ => println("closed"))
}
}
I would recommend you goto this website and check out the documentation. IT has all the information you need.
https://doc.akka.io/docs/akka/current/typed/actors.html
I'm trying to wrap my head around akka streams and the way to handle web sockets, but some things are quite clear to me.
For starters, I'm trying to accomplish one-way communication from some client to the server and communication between the same server and some other client.
client1 -----> Server <------> client2
I was looking at the example provided here.
The resulting code looks something like this:
1) starting with the controller
class Test #Inject()(#Named("connManager") myConnectionsManager: ActorRef, cc: ControllerComponents)
(implicit val actorSystem: ActorSystem,
val mat: Materializer,
implicit val executionContext: ExecutionContext)
extends AbstractController(cc) {
private def wsFutureFlow(id: String): Future[Flow[String, String, NotUsed]] = {
implicit val timeout: Timeout = Timeout(5.seconds)
val future = myConnectionsManager ? CreateRemote(id)
val futureFlow = future.mapTo[Flow[String, String, NotUsed]]
futureFlow
}
private def wsFutureLocalFlow: Future[Flow[String, String, NotUsed]] = {
implicit val timeout: Timeout = Timeout(5.seconds)
val future = myConnectionsManager ? CreateLocal
val futureFlow = future.mapTo[Flow[String, String, NotUsed]]
futureFlow
}
def ws: WebSocket = WebSocket.acceptOrResult[String, String] {
rh =>
wsFutureFlow(rh.id.toString).map { flow =>
Right(flow)
}
}
def wsLocal: WebSocket = WebSocket.acceptOrResult[String, String] {
_ =>
wsFutureLocalFlow.map { flow =>
Right(flow)
}
}
}
As for the connection manager actor. That would be the equivalent of the UserParentActor from the example.
class MyConnectionsManager #Inject()(childFactory: MyTestActor.Factory)
(implicit ec: ExecutionContext, mat: Materializer) extends Actor with InjectedActorSupport {
import akka.pattern.{ask, pipe}
implicit val timeout: Timeout = Timeout(2.seconds)
override def receive: Receive = {
case CreateRemote(x) =>
val child = injectedChild(childFactory(), s"remote-$x")
context.watch(child)
privatePipe(child)
case CreateLocal =>
val child = injectedChild(childFactory(), "localConnection")
context.become(onLocalConnected(child))
privatePipe(child)
case Terminated(child) =>
println(s"${child.path.name} terminated...")
}
def onLocalConnected(local: ActorRef): Receive = {
case CreateRemote(x) =>
val child = injectedChild(childFactory(), s"remote-$x")
context.watch(child)
privatePipe(child)
case x: SendToLocal => local ! x
}
private def privatePipe(child: ActorRef) = {
val future = (child ? Init).mapTo[Flow[String, String, _]]
pipe(future) to sender()
() // compiler throws exception without this: non-unit value discarded
}
}
And the MyTestActor looks like this:
class MyTestActor #Inject()(implicit mat: Materializer, ec: ExecutionContext) extends Actor {
val source: Source[String, Sink[String, NotUsed]] = MergeHub.source[String]
.recoverWithRetries(-1, { case _: Exception => Source.empty })
private val jsonSink: Sink[String, Future[Done]] = Sink.foreach { json =>
println(s"${self.path.name} got message: $json")
context.parent ! SendToLocal(json)
}
private lazy val websocketFlow: Flow[String, String, NotUsed] = {
Flow.fromSinkAndSourceCoupled(jsonSink, source).watchTermination() { (_, termination) =>
val name = self.path.name
termination.foreach(_ => context.stop(self))
NotUsed
}
}
def receive: Receive = {
case Init =>
println(s"${self.path.name}: INIT")
sender ! websocketFlow
case SendToLocal(x) =>
println(s"Local got from remote: $x")
case msg: String => sender ! s"Actor got message: $msg"
}
}
What I don't understand, apart from how sinks and sources actually connect to the actors, is the following. When I start up my system, I send a few messages to the actor. However, after I close the connection to an actor named remote, and continue sending messages to the one called "localConnection", the messages get sent to DeadLetters:
[info] Done compiling.
[info] 15:49:20.606 - play.api.Play - Application started (Dev)
localConnection: INIT
localConnection got message: test data
Local got from remote: test data
localConnection got message: hello world
Local got from remote: hello world
remote-133: INIT
remote-133 got message: hello world
Local got from remote: hello world
remote-133 got message: hello from remote
Local got from remote: hello from remote
[error] 15:50:24.449 - a.a.OneForOneStrategy - Monitored actor [Actor[akka://application/user/connManager/remote-133#-998945083]] terminated
akka.actor.DeathPactException: Monitored actor [Actor[akka://application/user/connManager/remote-133#-998945083]] terminated
deadLetters got message: hello local
I assume this is because of the exception thrown... Can anyone explain to me as to why the message gets sent to DeadLetters?
Apart from that, I would like to know why I keep getting a compiler exception without the "()" returned at the end of privatePipe?
Also, should I be doing anything differently?
I realised that the exception was being thrown because I forgot to handle the Terminated message in the new behaviour of the MyConnectionsManager actor.
def onLocalConnected(local: ActorRef): Receive = {
case CreateRemote(x) =>
val child = injectedChild(childFactory(), s"remote-$x")
context.watch(child)
privatePipe(child)
case Terminated(child) => println(s"${child.path.name} terminated...")
case x: SendToLocal => local ! x
}
It seems to be working now.
I'm trying to follow this part of the akka-http documentation where it talks about handling web socket messages asynchronously
What I am trying to do is this:
Receive a websocket request for a client
Serve a payment invoice back to the client
Run a background process that has the client's websocket connection saved, and when the client pays their invoice, send the data they queried about in return ("World") in this case.
Here is the code I have so far
def hello: Route = {
val amt = 1000
val helloRoute: Route = pathPrefix(Constants.apiVersion) {
path("hello") {
val source: Source[Message, SourceQueueWithComplete[Message]] = {
Source.queue(1, OverflowStrategy.backpressure)
}
val paymentRequest = createPaymentRequest(1000, extractUpgradeToWebSocket)
Directives.handleWebSocketMessages(
paymentFlow(paymentRequest)
)
}
}
helloRoute
}
private def createPaymentRequest(amt: Long, wsUpgrade: Directive1[UpgradeToWebSocket]) = {
val httpResponse: Directive1[HttpResponse] = wsUpgrade.map { ws =>
val sink: Sink[Message, NotUsed] = Sink.cancelled()
val source: Source[Message, NotUsed] = Source.single(TextMessage("World"))
val x: HttpResponse = ws.handleMessagesWithSinkSource(sink, source)
x
}
httpResponse.map { resp =>
//here is where I want to send a websocket message back to the client
//that is the HttpResponse above, how do I complete this?
Directives.complete(resp)
}
}
What I can't seem to figure out is how to get access to a RequestContext or a UpgradeToWebSocket outside of the container type Directive? And when I map on httpResponse the map is not executing.
Here is the setup: I want to be able to stream messages (jsons converted to bytestrings) from a publisher to a remote server subscriber over a tcp connection.
Ideally, the publisher would be an actor that would receive internal messages, queue them and then stream them to the subscriber server if there is outstanding demand of course. I understood that what is necessary for this is to extend ActorPublisher class in order to onNext() the messages when needed.
My problem is that so far I am able just to send (receive and decode properly) one shot messages to the server opening a new connection each time. I did not manage to get my head around the akka doc and be able to set the proper tcp Flow with the ActorPublisher.
Here is the code from the publisher:
def send(message: Message): Unit = {
val system = Akka.system()
implicit val sys = system
import system.dispatcher
implicit val materializer = ActorMaterializer()
val address = Play.current.configuration.getString("eventservice.location").getOrElse("localhost")
val port = Play.current.configuration.getInt("eventservice.port").getOrElse(9000)
/*** Try with actorPublisher ***/
//val result = Source.actorPublisher[Message] (Props[EventActor]).via(Flow[Message].map(Json.toJson(_).toString.map(ByteString(_))))
/*** Try with actorRef ***/
/*val source = Source.actorRef[Message](0, OverflowStrategy.fail).map(
m => {
Logger.info(s"Sending message: ${m.toString}")
ByteString(Json.toJson(m).toString)
}
)
val ref = Flow[ByteString].via(Tcp().outgoingConnection(address, port)).to(Sink.ignore).runWith(source)*/
val result = Source(Json.toJson(message).toString.map(ByteString(_))).
via(Tcp().outgoingConnection(address, port)).
runFold(ByteString.empty) { (acc, in) ⇒ acc ++ in }//Handle the future
}
and the code from the actor which is quite standard in the end:
import akka.actor.Actor
import akka.stream.actor.ActorSubscriberMessage.{OnComplete, OnError}
import akka.stream.actor.{ActorPublisherMessage, ActorPublisher}
import models.events.Message
import play.api.Logger
import scala.collection.mutable
class EventActor extends Actor with ActorPublisher[Message] {
import ActorPublisherMessage._
var queue: mutable.Queue[Message] = mutable.Queue.empty
def receive = {
case m: Message =>
Logger.info(s"EventActor - message received and queued: ${m.toString}")
queue.enqueue(m)
publish()
case Request => publish()
case Cancel =>
Logger.info("EventActor - cancel message received")
context.stop(self)
case OnError(err: Exception) =>
Logger.info("EventActor - error message received")
onError(err)
context.stop(self)
case OnComplete =>
Logger.info("EventActor - onComplete message received")
onComplete()
context.stop(self)
}
def publish() = {
while (queue.nonEmpty && isActive && totalDemand > 0) {
Logger.info("EventActor - message published")
onNext(queue.dequeue())
}
}
I can provide the code from the subscriber if necessary:
def connect(system: ActorSystem, address: String, port: Int): Unit = {
implicit val sys = system
import system.dispatcher
implicit val materializer = ActorMaterializer()
val handler = Sink.foreach[Tcp.IncomingConnection] { conn =>
Logger.info("Event server connected to: " + conn.remoteAddress)
// Get the ByteString flow and reconstruct the msg for handling and then output it back
// that is how handleWith work apparently
conn.handleWith(
Flow[ByteString].fold(ByteString.empty)((acc, b) => acc ++ b).
map(b => handleIncomingMessages(system, b.utf8String)).
map(ByteString(_))
)
}
val connections = Tcp().bind(address, port)
val binding = connections.to(handler).run()
binding.onComplete {
case Success(b) =>
Logger.info("Event server started, listening on: " + b.localAddress)
case Failure(e) =>
Logger.info(s"Event server could not bind to $address:$port: ${e.getMessage}")
system.terminate()
}
}
thanks in advance for the hints.
My first recommendation is to not write your own queue logic. Akka provides this out-of-the-box. You also don't need to write your own Actor, Akka Streams can provide it as well.
First we can create the Flow that will connect your publisher to your subscriber via Tcp. In your publisher code you only need to create the ActorSystem once and connect to the outside server once:
//this code is at top level of your application
implicit val actorSystem = ActorSystem()
implicit val actorMaterializer = ActorMaterializer()
import actorSystem.dispatcher
val host = Play.current.configuration.getString("eventservice.location").getOrElse("localhost")
val port = Play.current.configuration.getInt("eventservice.port").getOrElse(9000)
val publishFlow = Tcp().outgoingConnection(host, port)
publishFlow is a Flow that will input ByteString data that you want to send to the external subscriber and outputs ByteString data that comes from subscriber:
// data to subscriber ----> publishFlow ----> data returned from subscriber
The next step is the publisher Source. Instead of writing your own Actor you can use Source.actorRef to "materialize" the Stream into an ActorRef. Essentially the Stream will become an ActorRef for us to use later:
//these values control the buffer
val bufferSize = 1024
val overflowStrategy = akka.stream.OverflowStrategy.dropHead
val messageSource = Source.actorRef[Message](bufferSize, overflowStrategy)
We also need a Flow to convert Messages into ByteString
val marshalFlow =
Flow[Message].map(message => ByteString(Json.toJson(message).toString))
Finally we can connect all of the pieces. Since you aren't receiving any data back from the external subscriber we'll ignore any data coming in from the connection:
val subscriberRef : ActorRef = messageSource.via(marshalFlow)
.via(publishFlow)
.runWith(Sink.ignore)
We can now treat this stream as if it were an Actor:
val message1 : Message = ???
subscriberRef ! message1
val message2 : Message = ???
subscriberRef ! message2
Here is what the document recommends and it does work.
import play.api.mvc._
import play.api.libs.iteratee._
import play.api.libs.concurrent.Execution.Implicits.defaultContext
def socket = WebSocket.using[String] { request =>
// Concurrent.broadcast returns (Enumerator, Concurrent.Channel)
val (out, channel) = Concurrent.broadcast[String]
// log the message to stdout and send response back to client
val in = Iteratee.foreach[String] {
msg => println(msg)
// the Enumerator returned by Concurrent.broadcast subscribes to the channel and will
// receive the pushed messages
channel push("I received your message: " + msg)
}
(in,out)
}
However it is not working if I changed to:
def socket = WebSocket.using[String] { request =>
val (out, channel) = Concurrent.broadcast[String]
val in=Iteratee.ignore[String]
channel push("Hello World")
(in,out)
}
I'd appreciate if you can help me understand why it is not working with the new approach.
Thanks
James
Update:
class ServiceHandler extends Actor {
import Tcp._
val (enumerator, channel) = Concurrent.broadcast[String]
val system=ActorDict.system
def receive = {
case subscribeData() =>{
sender ! enumerator
}
case Received(data) => {
val dst = data.decodeString("utf-8")
val va=dst.substring(dst.lastIndexOf(',') + 1).trim()
println(va)
channel.push(va)
}
case PeerClosed => context stop self
}
}
def ws = WebSocket.using[String] { request =>
val in=Iteratee.ignore[String]
val dataHandler = Akka.system.actorOf(Props[ServiceHandler])
val out= Await.result((dataHandler ? subscribeData()), 5 seconds).asInstanceOf[Enumerator[String]]
(in,out)
}
You will not receive the "hello world" in the client side because you're pushing it to the channel before the connection is established with the client.
If you don't need to receive anything from the client ( this is why you're doing val in=Iteratee.ignore[String] ) You'd better go with server sent events:
Ok.chunked(out &> EventSource()).as("text/event-stream")