Now, it's time to run our RunnableGraph here and find the results. We can run a RunnableGraph by calling its run function, as follows:
import akka.stream.scaladsl.{Flow, Sink, Source} object AkkaStreamsNumbersApp extends App{ val numbersSource = Source(1 to 10) val sampleSink = Sink.foreach(println) val numberFlow = Flow[Int].map(num => num+1) val numberRunnableGraph =
numbersSource.via(numberFlow).to(sampleSink) numberRunnableGraph.run }
When we run the preceding program, we will get the following error messages:
Error:(18, 23) could not find implicit value for parameter materializer: akka.stream.Materializer
numberRunnableGraph.run
Error:(18, 23) not enough arguments for method run: (implicit materializer: akka.stream.Materializer)akka.NotUsed.
Unspecified value parameter materializer.
numberRunnableGraph...