A stack implementation using linked list in java

LinkedStack.java

/**
 * a stack implementation using linked list
 * @author Anim Malvat
 */
public class LinkedStack {
    /**
     * top pointer for stack
     */
    private Node top = null;
    /**
     * size of the stack
     */
    private int size = 0;

    /**
     * helper class that contains the information of the node
     */
    public class Node {
        /**
         * integer data to be stored
         */
        private int data;

        /**
         * reference to the next element
         */
        private Node next;

        /**
         * constructor of the node with value to be stored
         */
        public Node(int data) {
            this.data = data;
            this.next = null;
        }

        /**
         * getter for the data
         * @return the data
         */
        public int getData() {
            return this.data;
        }

        /**
         * getter for the next reference
         * @return  node
         */
        public Node getNext() {
            return this.next;
        }

        /**
         * sets the data of the node
         * @param data  integer data to be stored
         */
        public void setData(int data) {
            this.data = data;
        }

        /**
         * sets the next reference of the node
         * @param next  Node reference of the next node
         */
        public void setNext(Node next) {
            this.next = next;
        }
    }

    /**
     * adds the element on the top pointer 
     * @param data
     */
    public void push(int data) {
        this.size += 1;
        if (this.top == null) {
            this.top = new Node(data);
        } else {
            Node second = this.top;
            this.top = new Node(data);
            this.top.setNext(second);
        }
    }

    /**
     * removes the top most element and returns
     * @return
     */
    public int pop() {
        this.size -= 1;
        int value = this.top.getData();
        this.top = this.top.getNext();
        return value;
    }

    /**
     * displays the stack
     */
    public void display() {
        Node iterator = this.top;
        while (iterator != null) {
            System.out.print(iterator.getData() + " ");
            iterator = iterator.getNext();
        }
        System.out.println();
    }

    /**
     * returns the size of the stack
     * @return
     */
    public int getSize() {
        return size;
    }
    public static void main(String[] args) {
        LinkedStack stack = new LinkedStack();
        stack.push(3);
        stack.push(2);
        stack.push(1);
        stack.display();
        stack.pop();
        stack.display();
        System.out.println("this size of the stack is : " + stack.getSize());
    }
}