(But only with Java8)

There is no java.util.concurrent.Future.await()

Yes there is an

await

on

CompletionStage

. But you have to add

kotlinx-coroutines-jdk8

as a dependency of your project

no sorry I'm wrong.CompletionStage implements Future

but Future doesn't implement CompletionStage. So if you use

java.util.concurrent.Future

your only option is to create a task to wait on the result:

async { future.get() }