在Java中如何从字母表中的"z“循环回到"a”？

public class AlphabetLoop {
    public static void main(String[] args) {
        char currentLetter = 'z';
        int asciiValue = (int) currentLetter;

        if (asciiValue == (int) 'a') {
            asciiValue = (int) 'z' + 1;
        } else {
            asciiValue--;
        }

        char nextLetter = (char) asciiValue;
        System.out.println("循环回到的字母是：" + nextLetter);
    }
}