While using integer in the place of int it's working. Why not with int

Question

import java.util.HashMap ;
class MyClass {
public static void main(String[]args){

//in the below object if I change Integer with int it's working. explain me why it's not working with int
HashMap<String,int> f = new HashMap<String,int>();
f.put("senthil",200);
f.put("santy",100);
System.out.println(f.get("santy"));

}
}

Answer 1

int will not work because you have to specific an object type not a primitive type. Integer is an wrapper class for int
https://www.sololearn.com/learn/432/?ref=app

Answer 2

Because you have specific it an objective type not a primitive type