A bug of ThreadLocal's javadoc

I can't login to http://bugs.sun.com/ these days. So I write it here for reference. In line 39 of ThreadLocal.java (http://download.oracle.com/javase/6/docs/api/java/lang/ThreadLocal.html), uniqueId should be uniqueNum. The following code shows the reason. 

 

import java.util.concurrent.atomic.AtomicInteger;

class UniqueThreadIdGenerator {

  private static final AtomicInteger uniqueId = new AtomicInteger(0);

  private static final ThreadLocal<Integer> uniqueNum = 
    new ThreadLocal<Integer> () {
      @Override protected Integer initialValue() {
        return uniqueId.getAndIncrement();
      }
    };

  public static int getCurrentThreadId() {
    return uniqueNum.get();
  }
} // UniqueThreadIdGenerator

public class Bug {
  public static void main (String [] args) {
     Worker w1 = new Worker(); 
     Worker w2 = new Worker(); 
     w1.start();
     w2.start();
  }
  static class Worker extends Thread {
    @Override
    public void run() {
      System.out.println("number: " + UniqueThreadIdGenerator.getCurrentThreadId());  
    }
  }
}

 The above program prints:

 

number: 0

number: 1

If I can return uniqueNum.get() to return uniqueId.get(). It prints:

number: 0

number: 0