Sender.scala

val serverLocator = {
  val nettyParams = new java.util.HashMap[String, Object]()
  nettyParams.put(TransportConstants.HOST_PROP_NAME, "localhost")
  nettyParams.put(TransportConstants.PORT_PROP_NAME, "5445")

  val sl = HornetQClient.createServerLocatorWithHA(
    new TransportConfiguration(classOf[NettyConnectorFactory].getName, nettyParams))

  sl.setConfirmationWindowSize(1048576)

  sl.setBlockOnDurableSend(false)
  sl.setBlockOnAcknowledge(false)

  sl
}

val sf = serverLocator.createSessionFactory()

val session = sf.createSession(true, true, 0)
session.createQueue(QueueName, QueueName, true)

val producer = session.createProducer(QueueName)

val semaphore = new Semaphore(0)
session.setSendAcknowledgementHandler(new SendAcknowledgementHandler {
  override def sendAcknowledged(message: Message) = {
    semaphore.release(1)
  }
})

def send(msgs: List[String]) {
  for (rawMsg <- msgs) {
    val msg = session.createMessage(true)
    msg.putStringProperty(ContentPropertyName, rawMsg)
    producer.send(msg)
  }

  semaphore.acquire(msgs.size)
}