How can I make program in java that convert capital letter to small letter

public static void average( char [] letter ) {

for (int I = 0; I < letter.length; I++) {
letter[i] = Character.toLowerCase(letter);
}

System.out.println(Arrays.toString(letter));
}

import java.util.Scanner;






public class Convert {
static String s;
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter Text Here : ");
s=scanner.nextLine();


System.out.println("Your text in Lower Case : "+s.toLowerCase());

}


}