How to use sleep() to wait for a while

[Java Tip]

This Java tip shows how to use sleep() method of threads to wait for a while.

public class SleepingThread extends Thread {

  private int countDown = 5;

  private static int threadCount = 0;

  public SleepingThread() {
    super("" + ++threadCount);
    start();
  }

  public String toString() {
    return "#" + getName() + ": " + countDown;
  }

  public void run() {
    while (true) {
      System.out.println(this);
      if (--countDown == 0)
        return;
      try {
        sleep(100);
      } catch (InterruptedException e) {
        throw new RuntimeException(e);
      }
    }
  }

  public static void main(String[] args) throws InterruptedException {
    for (int i = 0; i < 5; i++)
      new SleepingThread().join();
  }
}