Linked List implementation - Java program

Java implementation of the Linked List  is given below.





package lab.linkedlist;



public class LinkedList
{


public ListNode headnode;
public ListNode currentNode;
public ListNode lastnode;


public LinkedList()
{
headnode=null;  
currentNode=null;
lastnode=null;
}


public void insertBegining(Object info)
{
ListNode tmpnode=new ListNode();
tmpnode.data=info;
if(headnode==null)
{
tmpnode.nextnode=null;
lastnode=tmpnode;
}
else
{
tmpnode.nextnode=headnode;
}
headnode=tmpnode;
}






public Object getFirstinList()
{
if (headnode!=null)
{
return headnode.data;
}
else
{
return null;
}
}




public void deleteFirstInList()
{
if(headnode!=null)
{
headnode=headnode.nextnode;
}
else
{
return;
}

}


public Object getNextNode()
{
ListNode temp=currentNode;
if(currentNode==null)
{return null;}
else{
currentNode=currentNode.nextnode;
     return temp.data ;
   }
}

public void startIterator()
{
currentNode=headnode;
}


public void insertEnd(Object info)
{
ListNode tmpnode=new ListNode();
tmpnode.data=info;
if(headnode==null)
{
headnode=tmpnode;
}
else
{
lastnode.nextnode=tmpnode;
}
tmpnode.nextnode=null;
lastnode=tmpnode;
}


}





package lab.general;


public class Node {


public Object data;

public Node(Object dat){
data=dat;
               }


public Node()
{
data=null;
}
}

package lab.linkedlist;

import lab.general.Node;

public class ListNode extends Node {

ListNode nextnode;

}