Learning Linklist implement with java language

DoubleLinkList.java

package Main;

public class DoubleLinkList {
	private DoubleLinkList prev;
	private int data;
	private DoubleLinkList next;
	
	public void add (int value) {
		DoubleLinkList node = this;
		DoubleLinkList prevNode = new DoubleLinkList();
		while (node.next != null) {
			prevNode = node;
			node = node.next;
		}
		node.prev = prevNode;
		node.data = value;
		node.next = new DoubleLinkList ();
	}
	
        public void print () {
		DoubleLinkList node = this;
		while (node.next != null) {
			System.out.println (node.data);
			node = node.next;
		}
	}

	public int getData () {
		return data;
	}
	
	public DoubleLinkList getNext () {
		return next;
	}
	
	public DoubleLinkList getPrev () {
		return prev;
	}
}

main.java

package Main;

public class main {
	public static void main (String[] args) {
		Node list = new Node ();
		
		list.add(100);
		
		System.out.println (list.getN());
		System.out.println (list.getNext());
		
		list.add(200);
		
		System.out.println (list.getNext().getN());
		System.out.println (list.getNext().getNext());
	}
}

Node.java

package Main;

public class Node {
	private int n;
	private Node next;
	
	public void add (int num) {
		Node nextNode = this;
		while (nextNode.next != null) {
			nextNode = nextNode.next;
		}
		nextNode.n = num;
		nextNode.next = new Node();
	}

        public void insert (int index, Node node) {
		Node nextNode = this;
		int count = 0;
		while (count != index) {
			nextNode = nextNode.next;
			count++;
		}
		node.next = nextNode.next;
		nextNode.next = node;
	}

        public void delete (int index) {
		Node pNode = this;
		Node nNode = pNode;
		int count = 0;
		while (count != index) {
			nNode = pNode;
			pNode = pNode.next;
			count++;
		}
		nNode.next = pNode.next;
	}
	
	public void print () {
		Node node = this;
		while (node.next != null) {
			System.out.println (node.n);
			node = node.next;
		}
	}

	public int getN () {
		return n;
	}
	
	public Node getNext () {
		return next;
	}
}