Trying out Futures in scala with callbacks

ScalaFuture.scala

/**
 * Created by init on 4/4/15.
 */

import scala.concurrent._
import ExecutionContext.Implicits.global
import scala.util.{Failure, Success}

// implicit execution context
import scala.io.Source


object ScalaFuture extends App {

  def getAPIResponse() ={
    val result = Source.fromURL("https://api.instagram.com/v1/users/search?access_token=1808215450.97d681d.36499ceeca304b2f9ac4383ff712dda3&q=raghothams");

    /*
      adding bad API token to test failure callback

    val result = Source.fromURL("https://api.instagram.com/v1/users/search?access_token=1808215450.36499ceeca304b2f9ac4383ff712dda3&q=raghothams");
    */
    result.mkString
  }

  def sleep(duration: Long) { Thread.sleep(duration) }

  println("Hello Scala World")

  // create a future which will make the API call
  // Future is of type T
  // so it expects the type as a param
  // this also signifies the type returned by the future
  val f : Future [String] = Future {
    val res = getAPIResponse()
    res
  }

  println("loling....")

  // use the onComplete callback on the future f, to get the result
  // the result can be success / failure
  // handle response based on success / failure
  f onComplete {
    case Success(apiResponse) => println(apiResponse)

    case Failure(t) => println("An error occured "+t.getMessage())
  }

  // keep JVM alive till future returns
  sleep(4000)

}