Fetch exchange rates in Play2

ExchangeRateService.scala

package services

import javax.inject.Singleton

import play.api.libs.ws._
import play.api.Play.current
import scala.concurrent.Future
import scala.concurrent.ExecutionContext.Implicits.global

@Singleton
class ExchangeRateService
{

    implicit def client = WS.client

    def fetch(from: String, to: String): Future[Either[Error, Double]] = {

      val url: String = s"https://www.google.com/finance/converter?a=1&from=$from&to=$to"
      val response = WS.clientUrl(url).get()

      response.map(res => {

        val str = "<span class=bld>.+</span>".r.findFirstIn(res.body)
        if (str.isDefined){
          val rate = "[^0-9\\.]".r.replaceAllIn(str.get, "")
          Right(rate.toDouble)
        }
        else {
          Left(new Error(s"Invalid service response ${res.status} ${res.body}"))
        }
      })
    }
}