Future and FutureTask in java

// Java program do two FutureTask
// using Runnable Interface

import java.util.concurrent.*;
import java.util.logging.Level;
import java.util.logging.Logger;

class MyRunnable implements Runnable {

    private final long waitTime;

    public MyRunnable(int timeInMillis)
    {
        this.waitTime = timeInMillis;
    }

    @Override
    public void run()
    {
        try {
            // sleep for user given millisecond
            // before checking again
            Thread.sleep(waitTime);

            // return current thread name
            System.out.println(Thread
                                   .currentThread()
                                   .getName());
        }

        catch (InterruptedException ex) {
            Logger
                .getLogger(MyRunnable.class.getName())
                .log(Level.SEVERE, null, ex);
        }
    }
}

// Class FutureTaskExample execute two future task
class FutureTaskExample {

    public static void main(String[] args)
    {
        // create two object of MyRunnable class
        // for FutureTask and sleep 1000, 2000
        // millisecond before checking again
        MyRunnable myrunnableobject1 = new MyRunnable(1000);
        MyRunnable myrunnableobject2 = new MyRunnable(2000);

        FutureTask<String>
            futureTask1 = new FutureTask<>(myrunnableobject1,
                                           "FutureTask1 is complete");
        FutureTask<String>
            futureTask2 = new FutureTask<>(myrunnableobject2,
                                           "FutureTask2 is complete");

        // create thread pool of 2 size for ExecutorService
        ExecutorService executor = Executors.newFixedThreadPool(2);

        // submit futureTask1 to ExecutorService
        executor.submit(futureTask1);

        // submit futureTask2 to ExecutorService
        executor.submit(futureTask2);

        while (true) {
            try {

                // if both future task complete
                if (futureTask1.isDone() && futureTask2.isDone()) {

                    System.out.println("Both FutureTask Complete");

                    // shut down executor service
                    executor.shutdown();
                    return;
                }

                if (!futureTask1.isDone()) {

                    // wait indefinitely for future
                    // task to complete
                    System.out.println("FutureTask1 output = "
                                       + futureTask1.get());
                }

                System.out.println("Waiting for FutureTask2 to complete");

                // Wait if necessary for the computation to complete,
                // and then retrieves its result
                String s = futureTask2.get(250, TimeUnit.MILLISECONDS);

                if (s != null) {
                    System.out.println("FutureTask2 output=" + s);
                }
            }

            catch (Exception e) {
                System.out.println("Exception: " + e);
            }
        }
    }
}