Is there a Heap in java?

Question

I am porting a C++ library to Java and I need a heap data structure. Is there a standard implementation or will I need to do it myself?

Answer 1

For Java 8, updating on an existing answer:

You can use Java Priority Queue as a Heap.

Min Heap: --> to keep the min element always on top, so you can access it in O(1).

PriorityQueue<Integer> minHeap = new PriorityQueue<Integer>(); 

Max Heap: --> to keep the max element always on top, the same order as above.

PriorityQueue<Integer> maxHeap = new PriorityQueue<>(Comparator.reverseOrder()); 

Which is the same as (Integer o1, Integer o2) -> Integer.compare(o2, o1) or - Integer.compare(o1, o2) as suggested from other answers.

And you can use:
add --> to add element to the queue. O(log n)
remove --> to get and remove the min/max. O(log n)
peek --> to get, but not remove the min/max. O(1)

Answer 2

Min heap:

PriorityQueue<Integer> minHeap = new PriorityQueue<Integer>(); 

Max heap:

PriorityQueue<Integer> maxHeap = new PriorityQueue<Integer>(new Comparator<Integer>() {     @Override     public int compare(Integer o1, Integer o2) {         return - Integer.compare(o1, o2);     } });