List

import java.{lang, util}
import scala.collection.JavaConverters._
object Demo3 {
  def main(args: Array[String]): Unit = {
    val seqScala: List[Int] = List(1, 2, 3)
    val listJava: util.List[Int] = seqScala.asJava
    println(listJava)
}

Map

import java.{lang, util}
import scala.collection.JavaConverters._
object Demo3 {
  def main(args: Array[String]): Unit = {
    val mapScala: Map[Int, Int] = Map(1 -> 2, 3 -> 3)
    val mapJava: util.Map[Int, Int] = mapScala.asJava
    println(mapJava)
}