How to use join() method

[Java Tip]

This Java tip shows how to use join() method of threads.

Code:

class Sleeper extends Thread {
  private int duration;

  public Sleeper(String name, int sleepTime) {
    super(name);
    duration = sleepTime;
    start();
  }

  public void run() {
    try {
      sleep(duration);
    } catch (InterruptedException e) {
      System.out.println(getName() + " was interrupted. "
          + "isInterrupted(): " + isInterrupted());
      return;
    }
    System.out.println(getName() + " has awakened");
  }
}

class Joiner extends Thread {
  private Sleeper sleeper;

  public Joiner(String name, Sleeper sleeper) {
    super(name);
    this.sleeper = sleeper;
    start();
  }

  public void run() {
    try {
      sleeper.join();
    } catch (InterruptedException e) {
      throw new RuntimeException(e);
    }
    System.out.println(getName() + " join completed");
  }
}

public class Joining {

  public static void main(String[] args) {
    Sleeper sleepy = new Sleeper("Sleepy", 1500), grumpy = new Sleeper(
        "Grumpy", 1500);
    Joiner dopey = new Joiner("Dopey", sleepy), doc = new Joiner("Doc",
        grumpy);
    grumpy.interrupt();

  }
}