generics stack

public class Stack<T> implements StackInterface<T> {

    private int size;
    private int top = -1;

    private T[] stackArr;

    @SuppressWarnings("unchecked")
    private Stack() {
        size = 16;
        stackArr = (T[]) new Object[size];
    }

    @SuppressWarnings("unchecked")
    private Stack(int curSize) {
        size = curSize;
        stackArr = (T[]) new Object[size];
    }

    public void push(T entry) {
        if (isFull()) {
            System.out.println("Бля, щас как расширю");
            ensureCapacity();
        }
        System.out.println("Adding: " + entry);
        stackArr[++top] = entry;
    }

    public T pop() throws Exception {
        if (isEmpty()) {
            throw new Exception("Бля, ну ты и долбоёб");
        }
        T entry = stackArr[top--];
        System.out.println("Removed entry: " + entry);
        return entry;
    }

    public T peek() {
        return stackArr[top];
    }

    @SuppressWarnings("unchecked")
    private void ensureCapacity() {
        T[] newStack = (T[]) new Object[2 * size];
        if (size >= 0) {
            System.arraycopy(stackArr, 0, newStack, 0, size);
        }
        size *= 2;
        stackArr = newStack;
    }

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

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

    public int size() {
        return size;
    }

    public static void main(String[] args)  {
        Stack<Object> integerStack = new Stack<>(4);
        for (int i = 1; i <= 17; i++) {
            integerStack.push(i);
        }
        System.out.println(integerStack.size());
    }
}