ArrayDeque is a class in Java that implements the Deque interface using a resizable array. It provides the functionality of both a stack and a queue, and allows elements to be added or removed from both ends.

Here are some of the methods of ArrayDeque:

1. addFirst(E e): Adds the specified element to the front of the deque.

2. addLast(E e): Adds the specified element to the end of the deque.

3. offerFirst(E e): Inserts the specified element at the front of the deque, returning true upon success and false if the deque is full.

4. offerLast(E e): Inserts the specified element at the end of the deque, returning true upon success and false if the deque is full.

5. removeFirst(): Removes and returns the first element of the deque, throwing a NoSuchElementException if the deque is empty.

6. removeLast(): Removes and returns the last element of the deque, throwing a NoSuchElementException if the deque is empty.

7. pollFirst(): Retrieves and removes the first element of the deque, returning null if the deque is empty.

8. pollLast(): Retrieves and removes the last element of the deque, returning null if the deque is empty.

9. getFirst(): Retrieves, but does not remove, the first element of the deque, throwing a NoSuchElementException if the deque is empty.

10. getLast(): Retrieves, but does not remove, the last element of the deque, throwing a NoSuchElementException if the deque is empty.

11. peekFirst(): Retrieves, but does not remove, the first element of the deque, returning null if the deque is empty.

12. peekLast(): Retrieves, but does not remove, the last element of the deque, returning null if the deque is empty.

13. size(): Returns the number of elements in the deque.

14. isEmpty(): Returns true if the deque contains no elements.

15. clear(): Removes all elements from the deque.