TcpServerOneResponseThenComplete2.scala

import akka.actor.ActorSystem
import akka.stream.scaladsl.Flow
import akka.stream.scaladsl.Tcp
import akka.util.ByteString

object TcpServerOneResponseThenComplete2 {

  def main(args: Array[String]): Unit = {
    implicit val system = ActorSystem()
    import akka.stream.scaladsl.Framing

    val framing = Framing.delimiter(ByteString("\n"), 1024)

    Tcp().bind("127.0.0.1", 9999, halfClose = true).runForeach { incomingConnection =>
      incomingConnection.handleWith(Flow[ByteString]
        .via(framing)
        .take(1)
        .map { firstFrame =>
          println(s"Request: ${firstFrame.utf8String}")
          ByteString("Response\n")
        })
    }

  }

}