Modifying PriorityQueue keys while in queue

[Wesley May]

Is it acceptable to modify the keys of PriorityQueue elements while they are in the queue? That is, can I do something like this:

   
import java.util.*;

public class Queue
{
	public static int[] d;

	static Comparator<Integer> cmp = new Comparator<Integer>()
	{
		public int compare(Integer a, Integer b)
		{
			if(d[a] <= d[b])
				return -1;
			else
				return 1;
		}
	};

	public static void main(String args[])
	{
		PriorityQueue<Integer> q = new PriorityQueue<Integer>(10, cmp);

		d = new int[5];

		d[0] = 0;
		d[1] = 1;
		d[2] = 2;
		d[3] = 3;
		d[4] = 4;

		q.offer(0);
		q.offer(1);
		q.offer(2);
		q.offer(3);
		q.offer(4);

		d[0] = 2;
		d[1] = 5;
		d[2] = 1;
		d[3] = 4;
		d[4] = 3;

		while(!q.isEmpty())
			System.out.println(q.poll());
	}	
}
 

I expect to get 2, 0, 4, 3, 1 when I run this, but I actually get 0, 2, 4, 3, 1. This leads me to believe that elements only get sorted when they are inserted into the queue, and not when they're polled. Am I right? If so, is there some other structure I should be using instead for this? To the best of my knowledge, Priority Queues should allow for this...