The Kotlin plugin (for Android Studio; starting from 3.0 presumably built-in) allows for converting Java code to Kotlin automatically. Obviously the outcome is

The Kotlin plugin (for Android Studio; starting from 3.0 presumably built-in) allows for converting Java code to Kotlin automatically. Obviously the outcome is not necessarily idiomatic Kotlin, just the most straightforward equivalent - but still, it's a very quick way of getting up to speed with the syntax.