pilha node dinamica

package pilha;

public class Node {

    private Node next = null;
    private int value;

    public Node getNext() {
        return next;
    }

    public void setNext(Node next) {
        this.next = next;
    }

    public int getValue() {
        return value;
    }

    public void setValue(int value) {
        this.value = value;
    }
}

package pilha;

public class PilhaDin {

    Node top = null;

    public void push(Node element) {
        if (isEmpty()) {
            top = element;
        }else {
            element.setNext(top);
            top = element;
        }
    }

    public void pop() {
        if (!isEmpty()) {
            top = top.getNext();
        }else {
            System.out.println("Vazia");
        }
    }

    private boolean isEmpty() {
        if (top == null)
            return true;

        return false;
    }
}