Run a function periodically in Scala

Question

I want to call an arbitrary function every n seconds. Basically I want something identical to SetInterval from Javascript. How can I achieve this in Scala?

Answer 1

You could use standard stuff from java.util.concurrent:

import java.util.concurrent._  val ex = new ScheduledThreadPoolExecutor(1) val task = new Runnable {    def run() = println("Beep!")  } val f = ex.scheduleAtFixedRate(task, 1, 1, TimeUnit.SECONDS) f.cancel(false) 

Or java.util.Timer:

val t = new java.util.Timer() val task = new java.util.TimerTask {   def run() = println("Beep!")  } t.schedule(task, 1000L, 1000L) task.cancel() 

Answer 2

If you happen to be on Akka, Scheduler is quite convenient for this:

val system = ActorSystem("mySystem", config) // ...now with system in current scope: import system.dispatcher system.scheduler.schedule(10 seconds, 1 seconds) {   doSomeWork() } 

There is also scheduleOnce for one-off execution.

The usual warnings about closing over mutable state apply.