Please demonstrate Lock Interface using Example?

package com.test.yuvagen.basic;

import java.util.concurrent.locks.*;

/* Write a Java program that Demonstrate Lock Interface  

 * Read more:http://javainterviewprograms.blogspot.in/

 * */

public class LockThreadDemo {

          private final Lock queueLock = new ReentrantLock();

          public void print() {

                   queueLock.lock();

                   try {

                             Long duration = (long) (Math.random() * 10000);

                             System.out.println(Thread.currentThread().getName() + "\ttime taken" + (duration / 1000) + "sec");

                             Thread.sleep(duration);

                   } catch (Exception e) {

                             e.printStackTrace();

                   } finally {

                             queueLock.unlock();

                   }

          }

          public static void main(String args[]) {

                   LockThreadDemo lockDemo = new LockThreadDemo();

                   ThreadLock tl1 = new ThreadLock("Thread-1", lockDemo);

                   ThreadLock tl2 = new ThreadLock("Thread-2", lockDemo);

                   ThreadLock tl3 = new ThreadLock("Thread-3", lockDemo);

                   tl1.start();

                   tl2.start();

                   tl3.start();

          }

}

class ThreadLock extends Thread {

          LockThreadDemo lockDemo;

          ThreadLock(String name, LockThreadDemo lockDemo) {

                   super(name);

                   this.lockDemo = lockDemo;

          }

          @Override

          public void run() {

                   lockDemo.print();

          }

}

Output:

Thread-1   time taken3sec

Thread-2   time taken5sec

Thread-3   time taken6sec