找不到隐含的......:akka.http.server.RoutingSetup

Question

在玩akka-http实验1.0-M2时,我试图创建一个简单的Hello world示例.

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?"))
        }
      }
    }
  }
}

编译失败 could not find implicit value for parameter setup: akka.http.server.RoutingSetup

另外,如果我改变了

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

同

complete("Hello world?")

我收到另一个错误: type mismatch; found : String("Hello world?") required: akka.http.marshalling.ToResponseMarshallable

Answer 1

通过研究,我能够理解缺乏的问题Execution Context.要解决这个问题,我需要包含这个:

implicit val executionContext = system.dispatcher

调查akka/http/marshalling/ToResponseMarshallable.scala我看到ToResponseMarshallable.apply需要它返回一个Future[HttpResponse].

此外,在akka/http/server/RoutingSetup.scala,RoutingSetup.apply需要它.

可能是akka团队只需要添加更多的@implicitNotFounds.我能够找到不完全但相关的答案:在Akka中直接使用Futures并在升级到spray 1.2之后将Marshaller喷射到不在隐含范围内的期货