Collections.sort

20m.scala

case class A(value: Int)

def sort(a: java.util.List[A]) = {
    val c = new java.util.Comparator[A] {
        override def compare(x: A, y: A) = x.value - y.value
    }
    java.util.Collections.sort(a, c)
}

def profile[T](what: String)(action: => T) = {
    val start = System.currentTimeMillis()
    val r = action
    val delta = System.currentTimeMillis() - start
    println(what + ": " + delta + "; " + r)
}


while (true) {
    val a = new java.util.ArrayList[A]
    val r = new java.util.Random
    for (i <- 1 to 20 * 1000 * 1000) {
        a.add(new A(r.nextInt()))
    }
    profile("sort")(sort(a))
}