2021-03-02获取指定日期的指定N天后的前N个小时

 /**
     * 获取指定日期的指定N天后的前N个小时
     *
     * @param date
     * @param hours
     * @return
     */
    private Date getBeforeTime(Date date,int days, int hours) {
     
        Calendar c = Calendar.getInstance();
        //下面set方法前后顺序不能调换
        c.setTime(date);//设置时间
        //指定时间的七天以后
        c.set(Calendar.DATE, (c.get(Calendar.DATE) + days));
        //指定时间的四个小时前
        c.set(Calendar.HOUR_OF_DAY, (c.get(Calendar.HOUR_OF_DAY) - hours));
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        try {
     
            date = sdf.parse(sdf.format(c.getTime()));
        } catch (ParseException e) {
     
            e.printStackTrace();
        }
        return date;
    }