Question:

I’m migrating some signatures from f(long dur, TimeUnit timeUnit) to f(Duration duration), and would like to implement the former with the latter.
Being on Java 8, I can’t find any API to easily convert the long+TU to a Duration, the only idea that comes to me is to do something ugly like:
Or did I miss some API?

Answer:

Java 9+

You can use static method Duration.of(long, TemporalUnit).
It expects an amount as long, and a TemporalUnit, so you need to convert the TimeUnit into ChronoUnit.
Method toChronoUnit() was introduced in JDK version 9.

Java 8

With Java 8 you can translate TimeUnit into ChronoUnit using ThreeTen library’s utility method Temporals.chronoUnit​(TimeUnit)

If you have better answer, please add a comment about this, thank you!