how to delete last element in java.util.Set?

Question

i want to delete every last element of this set.

        Set<String> listOfSources = new TreeSet<String>();
        for(Route route:listOfRoutes){
            Set<Stop> stops = routeStopsService.getStops(route);
            for(Stop stop:stops)
               listOfSources.add(stop.getStopName());
         }

here i want to remove last element from listOfSources.

Answer 1

You will need to cast back to TreeSet, as Set's don't have any order.

listOfSources.remove( ((TreeSet) listOfSources).last() );

Answer 2

As an alternative you can set listOfSources as a SortedSet

SortedSet<String> listOfSources = new TreeSet<String>();

Then you can use last() method without casting to TreeSet

listOfSources.remove(listOfSources.last());

I think that this is a preferred approach since you suppose that your Set has an order.