public class MyRunnable implements Runnable
{
    public void run()
    {
        try
        {
            Thread.sleep(1000);
        }
        catch (InterruptedException e)
        {
            e.printStackTrace();
        }
        String threadName = Thread.currentThread().getName();
        /*
         * Returns the name of this thread group.
         */
        String threadGroupName = Thread.currentThread().getThreadGroup()
                .getName();

        System.out.println("Run by = " + threadName + " , Thread Group Name = "
                + threadGroupName);
    }
}

public class ThreadGroupDemo
{
    public static void main(String[] args) throws InterruptedException
    {
        MyRunnable myRunnable = new MyRunnable();

        ThreadGroup parentTg = new ThreadGroup("Parent ThreadGroup");

        Thread t1 = new Thread(parentTg, myRunnable, "thread1");
        Thread t2 = new Thread(parentTg, myRunnable, "thread2");

        t1.start();
        t2.start();

        ThreadGroup childTg = new ThreadGroup(parentTg, "Child ThreadGroup");

        Thread t3 = new Thread(childTg, myRunnable, "thread3");
        Thread t4 = new Thread(childTg, myRunnable, "thread4");
        Thread t5 = new Thread(childTg, myRunnable, "thread5");
        
        t3.start();
        t4.start();
        t5.start();

    }
}