DeadlockTest.java

public class DeadlockTest
{
    public static void main(String[] args)
    {
        final Foo a = new Foo();
        final Foo b = new Foo();

        new Thread(new Runnable()
        {
            @Override
            public void run()
            {
                sleepALitte();
                a.equals(b);
            }
        }).start();

        new Thread(new Runnable()
        {
            @Override
            public void run()
            {
                // sleep some time before firing threads
                // as to sync
                sleepALitte();
                b.equals(a);
            }
        }).start();

    }

    private static void sleepALitte()
    {
        try
        {
            Thread.sleep(3000);
        }
        catch (InterruptedException e)
        {
            e.printStackTrace();
        }
    }

    static class Foo {
        public synchronized boolean equals(Object o)
        {
            System.out.println("trying to get lock");

            synchronized (o) {
                /* IF you are not getting the deadlock then
                   try to uncomment the lines below */
//                System.out.println("do stuff");
//                sleepOneSecond();
            }

            return true;
        }
    }
}