Calling Scala code from Java with java.util.List when Scala's List is expected

pass_java_list_to_scala.scala

// Implicit 
import scala.collection.JavaConverters._

// For method:
def doSomething(things: List[Thing]): List[Result] = { ... }

// add the same method with another signature:
def doSomething(things: java.util.List[Thing]): java.util.List[Result] =
  doSomething(things.asScala.toList).asJava