spotify/scio#546 - JMapWrapper

JMapWrapper.scala

package com.spotify.scio.util

import java.lang.{Iterable => JIterable}
import java.util.{Map => JMap}
import scala.collection.JavaConverters._

private[scio] object JMapWrapper {
  def of[A, B](j: JMap[A, JIterable[B]]): Map[A, Iterable[B]] = {
    new Map[A, Iterable[B]] {
      // scalastyle:off method.name
      override def +[B1 >: Iterable[B]](kv: (A, B1)): Map[A, B1] =
        j.asScala.mapValues(_.asScala).toMap + kv
      override def -(key: A): Map[A, Iterable[B]] =
        j.asScala.mapValues(_.asScala).toMap - key
      // scalastyle:on method.name

      override def get(key: A): Option[Iterable[B]] = Option(j.get(key)).map(_.asScala)
      override def iterator: Iterator[(A, Iterable[B])] =
        j.asScala.iterator.map(kv => (kv._1, kv._2.asScala))
    }
  }

  def of[K, V](j: JMap[K, V]): Map[K, V] = {
    new Map[K, V] {
      // scalastyle:off method.name
      override def +[B1 >: V](kv: (K, B1)): Map[K, B1] = j.asScala.toMap + kv
      override def -(key: K): Map[K, V] = j.asScala.toMap - key
      // scalastyle:on method.name

      override def get(key: K): Option[V] = Option(j.get(key))
      override def iterator: Iterator[(K, V)] = j.asScala.iterator
    }
  }
}