How to use scala.None from Java code [duplicate]

Question

The scala.None$.MODULE$ thing doesn’t always typecheck, for example this doesn’t compile:

scala.Option<String> x = scala.None$.MODULE$;

because javac doesn’t know about Scala’s declaration-site variance, so you get:

J.java:3: incompatible types
found   : scala.None$
required: scala.Option<java.lang.String>
    scala.Option<String> x = scala.None$.MODULE$ ;

This does compile, though:

scala.Option<String> x = scala.Option.apply(null);

so that’s a different way to get a None that is usable in more situations.