Could not find implicit ...: akka.http.server.RoutingSetup

Question

While playing with akka-http experimental 1.0-M2, I am trying to create a simple Hello Hello example.

import akka.actor.ActorSystem import akka.http.Http import akka.http.model.HttpResponse import akka.http.server.Route import akka.stream.FlowMaterializer import akka.http.server.Directives._ object Server extends App { val host = "127.0.0.1" val port = "8080" implicit val system = ActorSystem("my-testing-system") implicit val fm = FlowMaterializer() val serverBinding = Http(system).bind(interface = host, port = port) serverBinding.connections.foreach { connection ⇒ println("Accepted new connection from: " + connection.remoteAddress) connection handleWith Route.handlerFlow { path("") { get { complete(HttpResponse(entity = "Hello world?")) } } } } } 

Compilation could not find implicit value for parameter setup: akka.http.server.RoutingSetup with could not find implicit value for parameter setup: akka.http.server.RoutingSetup

Also, if I change

 complete(HttpResponse(entity = "Hello world?")) 

with

 complete("Hello world?") 

I get another error: type mismatch; found : String("Hello world?") required: akka.http.marshalling.ToResponseMarshallable type mismatch; found : String("Hello world?") required: akka.http.marshalling.ToResponseMarshallable

Answer 1

In the course of research, I was able to understand the problem as a lack of Execution Context . To solve this problem, I needed to include this:

 implicit val executionContext = system.dispatcher 

akka/http/marshalling/ToResponseMarshallable.scala at akka/http/marshalling/ToResponseMarshallable.scala , I see ToResponseMarshallable.apply requires it, which returns Future[HttpResponse] .

Also, in akka/http/server/RoutingSetup.scala , RoutingSetup.apply needs it.

Maybe akka just needs to add some more @implicitNotFound s. I managed to find an inaccurate but related answer: direct use of futures in Akka and the Marshaller spray for futures are not implicit after upgrading to spray 1.2

Answer 2

Well-found - this problem still exists with Akka HTTP 1.0-RC2, so the code for this should now look like this (given their API changes):

 import akka.actor.ActorSystem import akka.http.scaladsl.server._ import akka.http.scaladsl._ import akka.stream.ActorFlowMaterializer import akka.stream.scaladsl.{Sink, Source} import akka.http.scaladsl.model.HttpResponse import Directives._ import scala.concurrent.Future object BootWithRouting extends App { val host = "127.0.0.1" val port = 8080 implicit val system = ActorSystem("my-testing-system") implicit val fm = ActorFlowMaterializer() implicit val executionContext = system.dispatcher val serverSource: Source[Http.IncomingConnection, Future[Http.ServerBinding]] = Http(system).bind(interface = host, port = port) serverSource.to(Sink.foreach { connection => println("Accepted new connection from: " + connection.remoteAddress) connection handleWith Route.handlerFlow { path("") { get { complete(HttpResponse(entity = "Hello world?")) } } } }).run() }