lifecycle.scala

trait Lifecycle {
  def startup(): Unit
  def shutdown(): Unit
}

trait FooModule extends Lifecycle {
  abstract override def startup() {
    super.startup()
    println("startup foo")
  }

  abstract override def shutdown() {
    super.shutdown()
    println("shutdown foo")
  }
}

trait BarModule extends Lifecycle {
  abstract override def startup() {
    super.startup()
    println("startup bar")
  }
}

trait LifecycleImpl extends Lifecycle {
  override def startup() { println("startup") }
  override def shutdown() { println("shutdown") }
}

trait Application extends LifecycleImpl

object Main {
  def main(args: Array[String]) = {
    val app = new Application with FooModule with BarModule {}
    app.startup()
    app.shutdown()
  }
}