Converting Java to Scala durations

I don’t know whether an explicit conversion is the only way, but if you want to do it right

FiniteDuration(d.toNanos, TimeUnit.NANOSECONDS)

toNanos will return the total duration, while getNano will only return the nanoseconds component, which is not what you want.

E.g.

import java.time.Duration
import jata.time.temporal.ChronoUnit
Duration.of(1, ChronoUnit.HOURS).getNano // 0
Duration.of(1, ChronoUnit.HOURS).toNanos  // 3600000000000L

That being said, you can also roll your own implicit conversion

implicit def asFiniteDuration(d: java.time.Duration) =
  scala.concurrent.duration.Duration.fromNanos(d.toNanos)

and when you have it in scope:

val d: FiniteDuration = ConfigFactory.load().getDuration("application.someTimeout")