Java获取当天或者明天等零点时间（00:00:00）0时0分0秒的方法

SimpleDateFormat sdfYMD = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.SECOND,0); //这是将当天的【秒】设置为0
calendar.set(Calendar.MINUTE,0); //这是将当天的【分】设置为0
calendar.set(Calendar.HOUR_OF_DAY,0); //这是将当天的【时】设置为0
String ymd = sdfYMD.format(calendar.getTime()); //2021-02-24 00:00:00
calendar.add(Calendar.DATE,1); //当前日期加一
String ymd2  = sdfYMD.format(calendar.getTime()); //获取第二天的时间 2021-02-25 00:00:00