Demonstration of the correct way to handle InterruptedException

InterruptedExceptionDemo.java

/**
 * Demonstrates correct (and incorrect) usage of catching InterruptedException.
 *
 * @author aakoch
 */
public class InterruptedExceptionDemo
{
    public static void main(String[] args) throws InterruptedException
    {
        Thread t = correctHandling();
        t.start();

        Thread.sleep(1100);

        t.interrupt();

        t = incorrectHandling();
        t.start();

        Thread.sleep(1100);

        t.interrupt();
    }

    private static Thread correctHandling()
    {
        Thread t = new Thread(new Runnable()
        {
            @Override public void run()
            {
                // check if the thread has been interrupted
                while (!Thread.interrupted())
                {
                    System.out.print('.');
                    try
                    {
                        Thread.sleep(500);
                    }
                    catch (InterruptedException e)
                    {
                        System.err.println("caught interrupted exception");
                        e.printStackTrace();

                        // make sure to reset the interrupted flag
                        Thread.currentThread().interrupt();
                    }
                }
            }
        });

        return t;
    }

    private static Thread incorrectHandling()
    {
        Thread t = new Thread(new Runnable()
        {
            @Override public void run()
            {

                while (!Thread.interrupted())
                {
                    System.out.print('.');
                    try
                    {
                        Thread.sleep(500);
                    }
                    catch (InterruptedException e)
                    {
                        System.err.println("caught interrupted exception");
                        e.printStackTrace();
                        // incorrect *not* to reset the interrupt status
                        // Thread.currentThread().interrupt();
                    }
                }
            }
        });

        return t;
    }

    private static Thread incorrectHandling2()
    {
        Thread t = new Thread(new Runnable()
        {
            @Override public void run()
            {

                // incorrect *not* to check if the thread was interrupted
                while (true)
                {
                    System.out.print('.');
                    try
                    {
                        Thread.sleep(500);
                    }
                    catch (InterruptedException e)
                    {
                        System.err.println("caught interrupted exception");
                        e.printStackTrace();
                        Thread.currentThread().interrupt();
                    }
                }
            }
        });

        return t;
    }
}