Node - pred.next = middle middle.prev = pred middle.next =...

class Node{
String item;
Node prev, next;
Node(String newItem){
item = newItem;
prev = next =null;
}
}
class CircularDoublyLinkedList{
private Node head;
private Node tail;
private int size;
CircularDoublyLinkedList(){
}
public void addFirst(String e){
if(size == 0)
{
tail =new Node(e);
head = tail;
}
else if(size == 1){
head =new Node(e);
head.next = tail;
head.prev = tail;
tail.prev = head;
tail.next = head;
}
else{
head.prev = new Node(e);
head.prev.next = head;
head.prev.prev = tail;
head = head.prev;
tail.next = head;
}
size ++;
}
public void addLast(String e){
if(size == 0)
{
tail = new Node(e);
head = tail;
}
else if(size == 1)
{
head.next = new Node(e);
head.prev = head.next;
head.next.prev = head;
head.next.next = head;
tail = head.next;
}
else {
tail.next = new Node(e);
tail.next.prev = tail;
tail.next.next = head;
head.prev = tail.next;
tail = tail.next;
}
size ++;

}
public void add(int index, String e){
if(index == 0) addFirst(e);
else if(index >= size) addLast(e);
else{
Node pred = head;
for(int i = 1; i < index; i++)
{
pred = pred.next;
}
Node succ = pred.next;
Node middle = new Node(e);