heap using priority queue java code example

Example 1: create a min heap in java using priority queue

int arr[]={1,2,1,3,3,5,7};
        PriorityQueue<Integer> a=new PriorityQueue<>();
        for(int i:arr){
            a.add(i);
        }
        while(!a.isEmpty())
            System.out.println(a.poll());

Example 2: priority queue max heap in java

//Sol1
PriorityQueue<Integer> queue = new PriorityQueue<>(10, Collections.reverseOrder());


//Sol2
// PriorityQueue<Integer> pq = new PriorityQueue<>((x, y) -> y - x);
PriorityQueue<Integer> pq =new PriorityQueue<>((x, y) -> Integer.compare(y, x));


//Sol3
PriorityQueue<Integer> pq = new PriorityQueue<Integer>(defaultSize, new Comparator<Integer>() {
    public int compare(Integer lhs, Integer rhs) {
        if (lhs < rhs) return +1;
        if (lhs.equals(rhs)) return 0;
        return -1;
    }
});