1public class Main {
2    static public void main(String[] args) throws Exception {
3        int millis = 1000;
4
5        if (args.length != 0) {
6            millis = Integer.parseInt(args[0]);
7        }
8
9        System.out.println("Sleeping " + millis + " msec...");
10
11        long start = System.currentTimeMillis();
12        Thread.sleep(millis);
13        long elapsed = System.currentTimeMillis() - start;
14        long offBy = Math.abs(elapsed - millis);
15
16        System.out.println("Done sleeping");
17
18        if (offBy > 250) {
19            System.out.println("Actually slept about " + elapsed + " msec...");
20        }
21    }
22}
23