java - Nested Map or equivalent to store triple -

i have store values list/map contains 3 values:

size  |   amount |  description 2,34  |     4    |  "i'm long string" 1,14  |     2    |  "i'm long string" 

so thought using nested map :

        map<double, map<integer,string>> = new hashmap<double, map<integer,string>>(); 

but how can easy add entries map? syntax

a.put(1,43, new map.entry<>(7,"9890")); 

didn't work, cause map abstract. best way nested map?

it's going tedious:

map<integer,string> val1 = a.get(2.34); if (val1 == null) {     val1 = new treemap<integer, string>();     a.put(2.34, val1); } val1.put(4, "i'm long string"); 

i've updated treemap since want access smallest element. should change map "a" treemap too.

edit 2

i made effort here, hope it's you're looking :)

import java.io.ioexception; import java.util.map; import java.util.treemap; import java.util.treeset;  public class main {      public static void main(string[] args) throws ioexception {         treemap<double, treemap<integer, string>> map = new treemap<>();         add(2.5, 5, "wrong value 1", map);         add(3, 2, "wrong value 2", map);         add(2.5, 3, "good value", map);          system.out.println(map.pollfirstentry().getvalue().pollfirstentry().getvalue());     }     public static void add(double val1, int val2, string val3, treemap<double, treemap<integer, string>> map) {         treemap<integer,string> submap = map.get(val1);         if (submap == null) {             submap = new treemap<integer, string>();             map.put(val1, submap);         }         submap.put(val2, val3);     }  }