SimpleScheduler.scala

final class JavaTimerScheduler {

  private val timer = new Timer()

  def scheduleOnce[T](delay: FiniteDuration)(job: => T)(implicit ec: ExecutionContext): JobHandler[T] = {
    val promise = Promise[T]
    val task = new TimerTask {
      def run(): Unit = {
        Future {
          val result = job // Execute a job
          promise.complete(Success(result))
        }
      }
    }
    timer.schedule(task, delay.toMillis)
    JobHandler(
      cancel = () => { task.cancel(); () },
      result = promise.future
    )
  }

  def schedule[U](interval: FiniteDuration)(job: => U)(implicit ec: ExecutionContext): Cancel = {
    val task = new TimerTask {
      def run(): Unit = Future { job }
    }
    val millis = interval.toMillis
    timer.schedule(task, millis, millis)
    () => { task.cancel(); () }
  }
}

type Cancel = () => Unit

case class JobHandler[+T](
  cancel: Cancel,
  result: Future[T]
)