TreeMap sorts the elements in ascending order by default. You can browse the items in the list in reverse order to display them in descending order using the Collections.reverseOrder().

public static Comparator reverseOrder(): This method returns a comparator object that allows sorting in descending order for an object collection that implements the Comparable.

import java.util.Collections; 
import java.util.Iterator; 
import java.util.Set; 
import java.util.TreeMap; 
import java.util.Map; 
 
public class reverseOrder {
 
 public static void main(String a[]){
 // Create a TreeMap
 TreeMap< String, Integer> tmap =
 new TreeMap< String, Integer> (Collections.reverseOrder()); 
 
 // Add key-value pairs to TreeMap
 tmap.put("Key1",1); 
 tmap.put("Key2",2); 
 tmap.put("Key3",3); 
 tmap.put("Key4",4); 
 
 // Get all inputs
 Set set = tmap.entrySet(); 
 
 // Get iterator to browse the list
 Iterator itr = set.iterator(); 
 
 // Show key-value pairs
 while(itr.hasNext()) {
 Map.Entry mentry = (Map.Entry)itr.next(); 
 System.out.print("key: "+mentry.getKey() + " - "); 
 System.out.println("Value: "+mentry.getValue()); 
 } 
 }
}

Result:

key: Key4 - Value: 4
key: Key3 - Value: 3
key: Key2 - Value: 2
key: Key1 - Value: 1

References:
Java doc:Collections.reverseOrder()