Generic Stack using Arraylist

class GenericStackArray<T> {
    private T[] stackArray;
    private int top;
    private int maxSize;

    @SuppressWarnings("unchecked")
    public GenericStackArray(int size) {
        this.maxSize = size;
        this.stackArray = (T[]) new Object[maxSize];
        this.top = -1;
    }

    public void push(T item) {
        if (top < maxSize - 1) {
            stackArray[++top] = item;
        } else {
            System.out.println("Stack Overflow");
        }
    }

    public T pop() {
        if (top >= 0) {
            return stackArray[top--];
        } else {
            System.out.println("Stack Underflow");
            return null;
        }
    }

    public boolean isEmpty() {
        return top == -1;
    }
}