时间工具 DateUtil

https://hutool.cn/docs/#/core/%E6%97%A5%E6%9C%9F%E6%97%B6%E9%97%B4/%E6%97%A5%E6%9C%9F%E6%97%B6%E9%97%B4%E5%B7%A5%E5%85%B7-DateUtil

获取指定时间

DateTime dateTime = DateUtil.nextMonth();

DateUtil对象返回的DateTime是Hutool包里的！调用.toString 就是 yyyy-MM-dd HH:mm:ss 格式的哦！

//昨天
DateUtil.yesterday()
//明天
DateUtil.tomorrow()
//上周
DateUtil.lastWeek()
//下周
DateUtil.nextWeek()
//上个月
DateUtil.lastMonth()
//下个月
DateUtil.nextMonth()

格式时间

    public static void main(String[] args) {
        DateTime dateTime = DateUtil.nextMonth(); // 默认是yyyy-MM-dd HH:mm:ss
        System.out.println(DateUtil.format(dateTime, "yyyy-MM-dd"));
    }

将Date类（及子类）转为JDK自带的LocalDateTime

        // 我是DateTime
        DateTime dateTime = DateUtil.nextMonth();
        // 我被转成LoclaDateTime了
        LocalDateTime localDateTime1 = DateUtil.toLocalDateTime(dateTime);

时间操作(获取、统计、推移)工具类 LocalDateTimeUtil

https://hutool.cn/docs/#/core/%E6%97%A5%E6%9C%9F%E6%97%B6%E9%97%B4/LocalDateTime%E5%B7%A5%E5%85%B7-LocalDateTimeUtil

将往前推2天

        LocalDateTime now = LocalDateTimeUtil.now();
        LocalDateTime localDateTime = now.plusDays(2L);
        System.out.println(DateUtil.format(localDateTime, "yyyy-MM-dd HH:mm:ss"));

计算时间差

        LocalDateTime startLocalDateTime = LocalDateTimeUtil.now();
        System.out.println(startLocalDateTime);
        LocalDateTime endLocalDateTime = LocalDateTimeUtil.now().plusDays(1);
        endLocalDateTime = endLocalDateTime.plusSeconds(3599);
        System.out.println(endLocalDateTime);
        System.out.println("两者差距(小时): " + LocalDateTimeUtil.between(startLocalDateTime, endLocalDateTime, ChronoUnit.HOURS)); // 自动抹去小数点，没有进位一说！
        System.out.println("两者差距(秒): " + LocalDateTimeUtil.between(startLocalDateTime, endLocalDateTime, ChronoUnit.SECONDS));