Check out example codes for "java treemap". It will help you in understanding the concepts better.

Code Example 1

import java.util.*;

// Declare the variable using the interface of the object for flexibility.
// Non-primative data types only.
Map<Integer, String> mambo = new TreeMap<Integer, String>();

mambo.put(key, value);
// TreeMap will be sorted by key.
// Work with any comparable object as a key.

mambo.put(1, "Monica");
mambo.put(2, "Erica");
mambo.put(3, "Rita");

Code Example 2

import java.util.TreeMap;
public class TreeMapFloorkeyExample
{
   public static void main(String[] args)
   {
      TreeMap<Integer, String> tm = new TreeMap<Integer, String>();
      tm.put(60, "apple");
      tm.put(10, "banana");
      tm.put(50, "cherry");
      tm.put(30, "fig");
      tm.put(80, "grape");
      tm.put(90, "kiwifruit");
      System.out.println("Checking greatest key less than or equal to 40: ");
      System.out.println("Value is: " + tm.floorKey(40));
   }
}

Learn ReactJs, React Native from akashmittal.com