akka-http send continuous chunked http response (stream) - scala

Question

I have this crude test example with akka-http client and server.
Server.scala:
import akka.actor.ActorSystem
import akka.stream.ActorMaterializer
import akka.stream.scaladsl.Sink
import akka.http.scaladsl.Http
import akka.http.scaladsl.model.HttpMethods._
import akka.http.scaladsl.model._
import scala.concurrent.Future
class Server extends Runnable {
def run() = {
implicit val system = ActorSystem("server")
implicit val materializer = ActorMaterializer()
val serverSource = Http().bind(interface = "localhost", port = 8200)
val requestHandler: HttpRequest => HttpResponse = {
case HttpRequest(GET, Uri.Path("/stream"), _, _, _) =>
HttpResponse(entity = HttpEntity(MediaTypes.`text/plain`, "test"))
}
val bindingFuture: Future[Http.ServerBinding] = serverSource.to(Sink.foreach { connection =>
connection handleWithSyncHandler requestHandler
}).run()
}
}
Client.scala:
import akka.actor.ActorSystem
import akka.http.scaladsl.Http
import akka.http.scaladsl.model.{Uri, HttpRequest}
import akka.stream.ActorMaterializer
object Client extends App {
implicit val system = ActorSystem("client")
import system.dispatcher
new Thread(new Server).start()
implicit val materializer = ActorMaterializer()
val source = Uri("http://localhost:8200/stream")
val finished = Http().singleRequest(HttpRequest(uri = source)).flatMap { response =>
response.entity.dataBytes.runForeach { chunk =>
println(chunk.utf8String)
}
}
}
At the moment Server just replies with a single "test".
How do I change the HttpResponse in Server to send "test" as chunked (stream) in an endless loop every 1 second?

Answer 1

Found the answer.
Server.scala:
import akka.actor.ActorSystem
import akka.stream.ActorMaterializer
import akka.stream.scaladsl.{Source, Sink}
import akka.http.scaladsl.Http
import akka.http.scaladsl.model.HttpMethods._
import akka.http.scaladsl.model._
import scala.concurrent.Future
import scala.concurrent.duration._
class Server extends Runnable {
def run() = {
implicit val system = ActorSystem("server")
implicit val materializer = ActorMaterializer()
val serverSource = Http().bind(interface = "localhost", port = 8200)
val requestHandler: HttpRequest => HttpResponse = {
case HttpRequest(GET, Uri.Path("/stream"), _, _, _) =>
HttpResponse(entity = HttpEntity.Chunked(ContentTypes.`text/plain`, Source(0 seconds, 1 seconds, "test")))
}
val bindingFuture: Future[Http.ServerBinding] = serverSource.to(Sink.foreach { connection =>
connection handleWithSyncHandler requestHandler
}).run()
}
}