java - Adding and removing elements to a double ended queue -

i have create double ended queue can add,remove , peek elements both sides (i.e, front , rear)

i got methods adding,removing , peeking elements @ 'head' unable figure out methods same thing 'tail' of queue

here code far:-

public class dequeue {     private node rear;     private node front;     private int counter;      class node      {         private string item;         private node link;     }      public node()     {         rear = front = null;         counter = 0;     }      public void hadd(string o)     {         node temp = new node();         temp.item =o;         temp.link =null;          if (rear==null)             front = rear = temp;          else         {             rear.link = temp;             rear = temp;         }         counter++;     }      public boolean isempty()     {         if(counter==0)             return true;         return false;     }      public object hpeek()     {         return rear.item;     }      public object hremove()     {         if (isempty())             return null;          else             {             object temp=front.item;             front = front.link;              if (front == null)                 rear = null;             counter--;             return temp;         }     }      public int size()     {         return counter;     }      public void tadd(string o)     {         node temp = new node();         temp.item =o;         temp.link =null;          if (front==null)             front=rear=temp;          else         {             front.link=temp;             front=temp;         }         counter++;     }      public object tpeek()     {         return front.item;     }      public object tremove()     {         if (isempty())             return null;          else         {             object temp=rear.item;             rear=rear.link;             if (rear==null)             front=null;             counter--;             return temp;         }     }       public string tostring()     {         stringbuilder result=new stringbuilder();         node curr=front;         while(curr!=null)         {             result.append(curr.item+" \n");             curr = curr.link;         }         return result.tostring();     } }