Java ArrayBlockingQueue.size()

public int size()

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
//  w  ww  .  j  a va 2 s .  c om
public class Main {
  public static void main(String[] argv) throws Exception {
    int capacity = 10;
    BlockingQueue<Integer> queue = new ArrayBlockingQueue<Integer>(capacity);

    int numWorkers = 2;
    Worker[] workers = new Worker[numWorkers];
    for (int i = 0; i < workers.length; i++) {
      workers[i] = new Worker(queue);
      workers[i].start();
    }

    for (int i = 0; i < 100; i++) {
      queue.put(i);
    }
  }
}

class Worker extends Thread {
  BlockingQueue<Integer> q;

  Worker(BlockingQueue<Integer> q) {
    this.q = q;
  }

  public void run() {
    try {
      while (true) {
        Integer x = q.take();
        System.out.println(q.size());
        if (x == null) {
          break;
        }
        System.out.println(x);
      }
    } catch (InterruptedException e) {
    }
  }
}