Java Thread Class

class MyThread extends Thread {
  public void run() {
    for (int i = 1; i <= 3; i++) {
      System.out.println("Thread running: " + i);
    }
  }

  public static void main(String[] args) {
    MyThread t = new MyThread();
    t.start();
  }
}

class Worker extends Thread {
  public void run() {
    System.out.println("Thread ID: " + Thread.currentThread().getId());
  }

  public static void main(String[] args) {
    for (int i = 0; i < 3; i++) {
      Worker w = new Worker();
      w.start();
    }
  }
}

class Demo extends Thread {
  String name;

  Demo(String n) {
    name = n;
  }

  public void run() {
    System.out.println(name + " is running");
  }

  public static void main(String[] args) {
    Demo d1 = new Demo("Thread A");
    Demo d2 = new Demo("Thread B");

    d1.start();
    d2.start();
  }
}

class SleepingThread extends Thread {
  public void run() {
    for (int i = 1; i <= 3; i++) {
      System.out.println(getName() + " running step " + i);
      try {
        Thread.sleep(500);
      } catch (InterruptedException e) {
        System.out.println(e);
      }
    }
  }

  public static void main(String[] args) {
    SleepingThread t1 = new SleepingThread();
    t1.setName("Alpha");
    t1.start();
  }
}