[람다인터페이스] 소문자 대문자로 바꾸는거

package april4;

import java.util.Scanner;

public class practice2 {
    public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String  g = sc.nextLine();

        action(a->a.toUpperCase(),g);

    }

    public static void action(upper u,String b){


        u.make(b);
        System.out.println(u.make(b));

    }
}

interface upper{
    public String make(String a);

}