NullPointerException in my route

Question

Can't figure this one out, but I get the following stacktrace for my route:

[ERROR] [09/06/2013 17:08:00.019] [example-akka.actor.default-dispatcher-5] [akka://example/user/$a] Error during processing of request HttpRequest(GET,/user/12345abcd?service=YT,List(Host: localhost:8080, Accept: /, User-Agent: curl/7.24.0 (x86_64-apple-darwin12.0) libcurl/7.24.0 OpenSSL/0.9.8x zlib/1.2.5),EmptyEntity,HTTP/1.1) java.lang.NullPointerException at spray.routing.directives.BasicDirectives$$anonfun$mapRequestContext$1$$anonfun$apply$1.apply(BasicDirectives.scala:30) at spray.routing.directives.BasicDirectives$$anonfun$mapRequestContext$1$$anonfun$apply$1.apply(BasicDirectives.scala:30) at spray.routing.directives.ExecutionDirectives$$anonfun$handleExceptions$1$$anonfun$apply$2.apply(ExecutionDirectives.scala:34) at spray.routing.directives.ExecutionDirectives$$anonfun$handleExceptions$1$$anonfun$apply$2.apply(ExecutionDirectives.scala:32) at spray.routing.HttpServiceBase$class.runSealedRoute$1(HttpService.scala:36) at spray.routing.HttpServiceBase$$anonfun$runRoute$1.applyOrElse(HttpService.scala:46) at akka.actor.ActorCell.receiveMessage(ActorCell.scala:498) at akka.actor.ActorCell.invoke(ActorCell.scala:456) at akka.dispatch.Mailbox.processMailbox(Mailbox.scala:237) at akka.dispatch.Mailbox.run(Mailbox.scala:219) at akka.dispatch.ForkJoinExecutorConfigurator$AkkaForkJoinTask.exec(AbstractDispatcher.scala:386) at scala.concurrent.forkjoin.ForkJoinTask.doExec(ForkJoinTask.java:260) at scala.concurrent.forkjoin.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1339) at scala.concurrent.forkjoin.ForkJoinPool.runWorker(ForkJoinPool.java:1979) at scala.concurrent.forkjoin.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:107)

My route looks like this:

class UserServiceActor extends Actor with UserService {
  def actorRefFactory = context
  def receive = runRoute(userServiceRoute)

}

trait UserService extends HttpService {

  val userServiceRoute = linkRoute

  val linkRoute =
    pathPrefix("user" / Segment) {
      userId =>
        path("link") {
          parameters('service ! "YT") {
            complete {
              "Done"
            }
          }
        }
    }
}

And the request I'm making is:

curl http://server.com/user/12345abcd/link?service=YT

Does anything seem like an obvious problem?

It's probably an initialization problem. Try making the route definition a def or a lazy val. — jrudolph
@jrudolph you're right, I changed them to be def and voila! Type that up as an answer and I'll accept it. — ThaDon

jrudolph jrudolph · Accepted Answer · 2013-09-08T07:55:15

It's probably an initialization problem. Try making the route definition a def or a lazy val.

Also there's a scalac flag -Xcheckinit which would add a runtime-check with a better error message trading in a bit of performance.

NullPointerException in my route

1 Answers