package mapsorttest06;
 
import java.util.Comparator;
import java.util.Map;
import java.util.TreeMap;
 
public class MapSortTest06 {
 
    public static void main(String[] args) {
        
        Map<Integer, String> treeMap = new TreeMap(
            new Comparator<Integer>() {
 
                @Override
                public int compare(Integer o1, Integer o2) {
                    return o2.compareTo(o1);
                }
        });
        
        treeMap.put(2, "Nick");
        treeMap.put(3, "Boris");
        treeMap.put(1, "Anton");
 
        System.out.println("Sorted treeMap: " + treeMap);
    }
 
}

Map<Integer, String> treeMap = new TreeMap(
            (Integer o1, Integer o2) -> o2.compareTo(o1));