add node between two node?

i have another question if i want two add node between two node in doubly linked list

add between is my method if i have two add method one for first and one for second what i shall do in my add between method

import java.util.NoSuchElementException;

public class DoublyLinkedListImpl<E> {

private Node head;

private Node tail;

private int size;

public DoublyLinkedListImpl() {

size = 0;

}

/**

* this class keeps track of each element information

* @author java2novice

*

*/

private class Node {

E element;

Node next;

Node prev;

public Node(E element, Node next, Node prev) {

this.element = element;

this.next = next;

this.prev = prev;

}

}

/**

* returns the size of the linked list

* @return

*/

public int size() { return size; }

/**

* return whether the list is empty or not

* @return

*/

public boolean isEmpty() { return size == 0; }

public E getFirstt()

{

return head.element;

}

public E getLast()

{

return tail.element;

}

/**

* adds element at the starting of the linked list

* @param element

*/

private void addBetween(Node e1, E elem, Node e2) {

prior.add(elem);

}