How you can do this with standard Java libraries:
Integer[] ints = new Integer[]{3,2,1};
// For reverse of natural order i.e. largest to smallest
// If you want the natural order don't use the Collections.reverseOrder() comparator
Queue<Integer> queue = new PriorityQueue<Integer>(ints.length, Collections.reverseOrder());
queue.addAll(Arrays.asList(ints));
while (queue.size() > 0) {
System.out.println(queue.poll());
}