Java 字符串转 Date，Date 转字符串，计算前一天后一天的日期时间

public static void main(String[] args) {
        String data1 = "2021-03-01-第二大节(10:00-11:30)";
        String rq = data1.substring(0, 10);  // 2020-09-21
        String sj = data1.substring(16, 21);  // 10:00

        System.out.println(rq + " " + sj);

        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm");
        try {
            Date data2 = formatter.parse(rq + " " + sj);
            Date beforeTime = new Date(data2.getTime() - 24 * 60 * 60 * 1000);  // 前一天

            System.out.println(formatter.format(beforeTime));
        } catch (ParseException e) {
            e.printStackTrace();
        }
    }