DOUBLE LINKEDLIST PROGRAM IN JAVA

 /**  
 DoubleLinkedlist.java: This program demonstrate How to create Double linked Node in java.   
 Author:itsafiz@gmail.com  
 */  
 import java.util.*;   
 class Node // Node class   
 {  
      int data; // data field  
      Node next; // address   
      Node pre; // address  
      Node(int data)  
      {  
           this.data=data;   
           next=null;  
           pre=null;   
      }  
 }  
 class DoubleLinkedlist  
 {  
 public static void main(String[]args)  
      {  
           int c,d;   
           Node start=null,head=null;   
           Scanner in = new Scanner(System.in);  
           while(true)  
           {       
           System.out.println("1.Insert\n2.Display \n3.Exit\n");                 
           c=in.nextInt();   
           switch(c)  
           {  
           case 1:   
                System.out.println("Enter Element");  
                d = in.nextInt();   
                Node temp = new Node(d);//  
                if(head==null){  
                     head=temp;   
                     start=head;}  
                else{  
                     head.next= temp;   
                     temp.pre=head;  
                     head=temp;                      
                  }  
           break;  
           case 2:   
                for(temp = start; temp!=null;temp=temp.next)  
                     System.out.print(temp.data);  
                System.out.println();   
                break;  
           default: System.exit(0);  
           }  
           }  
      }  
 }