Stream.scala

def stream[T](f: => T, t:T => Boolean):Stream[T] = {
    val v = f
    if (t(v)) Stream.cons(v, stream(f, t)) else Stream.empty
}

def whileNotNull[T](f: => T):Stream[T] = stream(f, {t:T => t != null})

StreamExample.scala

import java.io._
val br = new BufferedReader(new FileReader("foo.txt"))
val stream = whileNotNull(br.readLine) // get the scala Stream
stream.foreach { line => System.out.println(line) } // print out each line of the file