import java.util.Calendar;
import java.util.Locale;
import java.util.Map;
import java.util.NavigableMap;
import java.util.TreeMap;
public class NavigableMapSample {
public static void main(String args[]) {
Calendar now = Calendar.getInstance();
Locale locale = Locale.getDefault();
Map<String, Integer> names = now.getDisplayNames(Calendar.DAY_OF_WEEK, Calendar.LONG, locale);
NavigableMap<String, Integer> nav = new TreeMap<String, Integer>(names);
System.out.printf("Whole list:%n%s%n", nav);
System.out.printf("Key lower before Sunday: %s%n", nav.lowerKey("Sunday"));
}
}