How to convert Scala's List[Double] to java.util.List[java.lang.Double]?

问题

I have only seen examples where the result is a Java list of Scala doubles. I got as far as

def getDistance(): java.util.List[java.lang.Double] = {
  val javadistance = distance.toList.asJava
  javadistance
}

but this is still a Java list containing Scala doubles (distance is a member of the same class as getDistance).

回答1:

One has to use the java boxed variant in a map:

  def getDistance(): java.util.List[java.lang.Double] = {
    distance.toList.map(Double.box).asJava
  }

来源：https://stackoverflow.com/questions/46830217/how-to-convert-scalas-listdouble-to-java-util-listjava-lang-double