Id of a Thread in java pgm

Id of a Thread

public class Main extends Object implements Runnable

{

  private ThreadID var;

  public Main(ThreadID v)

 {

    this.var = v;

  }

  public void run()

 {

    try

    {

      print("var getThreadID =" + var.getThreadID());

      Thread.sleep(2000);

      print("var getThreadID =" + var.getThreadID());

      }

      catch (InterruptedException x) {}

  }

  private static void print(String msg)

 {

    String name = Thread.currentThread().getName();

    System.out.println(name + ": " + msg);

  }

  public static void main(String[] args)

   {

    ThreadID tid = new ThreadID();

    Main shared = new Main(tid);

    try

    {

      Thread threadA = new Thread(shared, "threadA");

      threadA.start();

      Thread.sleep(500);

      Thread threadB = new Thread(shared, "threadB");

      threadB.start();

      Thread.sleep(500);

      Thread threadC = new Thread(shared, "threadC");

      threadC.start();

      }

      catch (InterruptedException x) {}

  }

}

class ThreadID extends ThreadLocal

{

  private int nextID;

  public ThreadID()

 {

    nextID = 10001;

  }

  private synchronized Integer getNewID()

  {

    Integer id = new Integer(nextID);

    nextID++;

    return id;

  }

  protected Object initialValue()

 {

    print("in initialValue()");

    return getNewID();

  }

  public int getThreadID()

  {

    Integer id = (Integer) get();

    return id.intValue();

  }

  private static void print(String msg)

  {

    String name = Thread.currentThread().getName();

    System.out.println(name + ": " + msg);

  }

}