将Scala嵌套地图转换为Java嵌套util.Map

val scalaMap = Map("key1" -> Map("nestedKey1" -> "value1"), "key2" -> Map("nestedKey2" -> "value2"))

import java.util

val javaMap = new util.HashMap[String, util.Map[String, String]]()

scalaMap.foreach { case (key, nestedMap) =>
  val javaNestedMap = new util.HashMap[String, String]()
  nestedMap.foreach { case (nestedKey, value) =>
    javaNestedMap.put(nestedKey, value)
  }
  javaMap.put(key, javaNestedMap)
}