FinagleUdpClient.scala

class DelimEncoder(delim: Char) extends SimpleChannelHandler {
  override def writeRequested(ctx: ChannelHandlerContext, evt: MessageEvent) = {
    val newMessage = evt.getMessage match {
      case m: String => m + delim
      case m => m
    }
    Channels.write(ctx, evt.getFuture, newMessage, evt.getRemoteAddress)
  }
}

object StringClientPipeline extends ChannelPipelineFactory {
  def getPipeline = {
    val pipeline = Channels.pipeline()
    pipeline.addLast("stringEncode", new StringEncoder(CharsetUtil.UTF_8))
    pipeline.addLast("stringDecode", new StringDecoder(CharsetUtil.UTF_8))
    pipeline.addLast("line", new DelimEncoder('\n'))
    pipeline
  }
}

object Udp extends CodecFactory[String, Unit] {
  def server = throw new UnsupportedOperationException("clients only")
  def client = Function.const {
    new Codec[String, Unit] {
      def pipelineFactory = StringClientPipeline
    }
  }
}

val client = ClientBuilder()
             .codec(Udp)
             .channelFactory(new NioDatagramChannelFactory(Executors.newCachedThreadPool()))
             .hosts("127.0.0.1:2115")
             .build()

val f = client("request")