Extract parameters from a URL

URLutils.scala

import java.net.URI

object URLutils {

  type LS = List[String]

  /**
   * Extract a map of parameters from a URI
   * @param url
   * @return
   */
  def paramsToMap(url: URI): Map[String, LS] = {
    import java.net.URLDecoder
    def mkMap(s: String): Map[String, LS] = {
      val x = s.split('&').map(_.split('=').toList).collect {
        case k :: v :: Nil => Some(URLDecoder.decode(k, "utf-8") -> URLDecoder.decode(v, "utf-8"))
      }.flatten
      var m = Map.empty[String, LS].withDefaultValue(List.empty[String])
      x.foreach {
        t =>
          m = m + (t._1 -> (t._2 :: m(t._1)))
      }
      m
    }
    url.toString.dropWhile(_ != '?').toList match {
      case head :: tail => mkMap(tail.mkString)
      case _ => Map.empty[String, LS]
    }
  }
}