计算一周里面的星期几和计算redis截止当天24点的过期时间计算

public class CalcTime {
    public static void main(String[] args) {
        Calendar midnight = Calendar.getInstance();
        // 在当前日期上加一天
        midnight.add(Calendar.DATE, 1);

        midnight.set(Calendar.HOUR_OF_DAY, 0);
        midnight.set(Calendar.MINUTE, 0);
        midnight.set(Calendar.SECOND, 0);
        Date expireTime = midnight.getTime();
        System.out.println("expireTime=" + expireTime);
        long expireSeconds = (expireTime.getTime() - System.currentTimeMillis()) / 1000;
        System.out.println("expireSeconds=" + expireSeconds);

        System.out.println("getWeek=" + getWeek(new Date()));
    }

    /**
     * 星期天是第一天
     * @param date
     * @return
     */
    public static int getWeek(Date date) {
        if (null == date) {
            date = new Date();
        }
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        return cal.get(Calendar.DAY_OF_WEEK);
    }

}