listing the linkqueue java program /linkqueue java /demonstrates queue implemented as double-ended list /to run this programc>java linkqueueapp ///////////////////////////////////////////////////////////////class link public long ddata/data item public link next/next link in list /public link(long /constructor ddata /public void displaylink(/display this link system out print(ddata ")//end class link ///////////////////////////////////////////////////////////////class firstlastlist private link first/ref to first item private link last/ref to last item /public firstlastlist(/constructor first null/no items on list yet last null/public boolean isempty(/true if no links return first==null/public void insertlast(long dd/insert at end of list link newlink new link(dd)/make new link ifisempty(/if empty listfirst newlink/first --newlink else last next newlink/old last --newlink last newlink/newlink <-last /