system out print("list (first-->last)")link current first/start at beginning while(current !null/until end of listcurrent displaylink()/display data current current next/move to next link system out println("")/public void displaybackward(system out print("list (last-->first)")link current last/start at end while(current !null/until start of listcurrent displaylink()/display data current current previous/move to previous link system out println("")//end class doublylinkedlist ///////////////////////////////////////////////////////////////class doublylinkedapp public static void main(string[args/make new list doublylinkedlist thelist new doublylinkedlist()thelist insertfirst( )thelist insertfirst( )thelist insertfirst( )/insert at front thelist insertlast( )thelist insertlast( )thelist insertlast( )/insert at rear thelist displayforward()thelist displaybackward()/display list forward /display list backward thelist deletefirst()thelist deletelast()thelist deletekey( )/delete first item /delete last item /delete item with key