Question

我是akka框架的新手，现在尝试用这个框架设置简单的web服务写一个简单的akka-http应用程序：

import akka.actor.ActorSystem
import akka.http.scaladsl.Http
import akka.http.scaladsl.server.Directives._
import akka.stream.ActorMaterializer

import scala.io.StdIn

object MainRunner extends App {

  implicit val system = ActorSystem("mySystem")
  implicit val materializer = ActorMaterializer
  implicit val ec = system.dispatcher

  val route =
    path("hello") {
      get {
        complete("Congratulation , this is your response")
      }
    }

  val bindingFuture = Http().bindAndHandle(route, "localhost", 8080)

  println(s"Server online at http://localhost:8080/\nPress RETURN to stop...")
  StdIn.readLine() // let it run until user presses return
  bindingFuture
    .flatMap(_.unbind()) // trigger unbinding from the port
    .onComplete(_ => system.terminate()) // and shutdown when done
}

在编译时收到此错误：

Error:(34, 44) type mismatch;
 found   : akka.http.scaladsl.server.Route
    (which expands to)  akka.http.scaladsl.server.RequestContext => scala.concurrent.Future[akka.http.scaladsl.server.RouteResult]
 required: akka.stream.scaladsl.Flow[akka.http.scaladsl.model.HttpRequest,akka.http.scaladsl.model.HttpResponse,Any]
  val bindingFuture = Http().bindAndHandle(route, "localhost", 8080)

如何解决这个问题？

Answer 1

实例化ActorMaterializer：

时，这只是一个简单的错误

implicit val materializer = ActorMaterializer

应替换为

implicit val materializer = ActorMaterializer()

在作用域中使用有效的材质化程序时，Route和Flow[HttpRequest, HttpResponse, _]之间的隐式转换应按预期进行，编译器应该感到高兴。

akka http编译错误

1 个答案: