使用DateTimeFormatter的索引解析问题

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class Main {
    public static void main(String[] args) {
        String dateTimeString = "2022-01-01 12:30:45";
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        LocalDateTime dateTime = LocalDateTime.parse(dateTimeString, formatter);

        int year = dateTime.getYear();
        int month = dateTime.getMonthValue();
        int day = dateTime.getDayOfMonth();
        int hour = dateTime.getHour();
        int minute = dateTime.getMinute();
        int second = dateTime.getSecond();

        System.out.println("年：" + year);
        System.out.println("月：" + month);
        System.out.println("日：" + day);
        System.out.println("时：" + hour);
        System.out.println("分：" + minute);
        System.out.println("秒：" + second);
    }
}