Java PriorityQueue class

import java.util.PriorityQueue;

public class Main {
  public static void main(String[] args) {
    // queue of capacity 11
    PriorityQueue<Double> queue = new PriorityQueue<>();

    // insert elements to queue
    queue.offer(1.2);/*from  w  w  w.  jav  a  2s  .  com*/
    queue.offer(2.8);
    queue.offer(3.4);

    System.out.print("Polling from queue: ");

    // display elements in queue
    while (queue.size() > 0) {
      System.out.printf("%.1f ", queue.peek()); // view top element
      queue.poll(); // remove top element
    }
  }
}