HolydaysProvider.scala

import java.time.LocalDate
import java.time.format.DateTimeFormatter

import com.typesafe.config.{Config, ConfigFactory}

import scalaj.http.{Http, HttpRequest, HttpResponse}
import scala.xml.XML

object HolydaysProvider {
  def get(year: Option[String], state: Option[String], city: Option[String]): List[String] = {

    val apiUrl: String = "http://www.calendario.com.br/api/api_feriados.php"
    val config: Config = ConfigFactory.load()
    val token: String = config.getString("elektro.calendario.token")
    val baseRequest: HttpRequest = Http(apiUrl)
    val response: HttpResponse[String] = baseRequest
                                          .param("token", token)
                                          .param("year", year.getOrElse(""))
                                          .param("state", state.getOrElse(""))
                                          .param("city", city.getOrElse(""))
                                          .timeout(connTimeoutMs = 2000, readTimeoutMs = 5000)
                                          .asString
    val xmlString = response.body

    // convert the `String` to a `scala.xml.Elem`
    val xml = XML.loadString(xmlString)

    // handle the xml as desired ...
    val dates = xml \ "event" \ "date"
    val formatador: DateTimeFormatter  = DateTimeFormatter.ofPattern("dd/MM/yyyy")
    dates.map { date =>
      LocalDate.parse(date.text, formatador).toString
    }.toList
  }
}

WorkingDayHelper.scala

import java.time.LocalDate

import HolydaysProvider

object WorkingDayHelper {
  val holydays: List[String] = HolydaysProvider.get(Option("2017"), None, None)
  def next(date: Option[LocalDate]): LocalDate = {
    val nextDay = date.getOrElse(LocalDate.now).plusDays(1)
    if(holydays.indexOf(nextDay.toString) < 0 && nextDay.getDayOfWeek.getValue <= 5) {
      nextDay
    } else {
      next(Option(nextDay))
    }
  }
}