Java 獲取當天的零點時間戳

/**
     * 獲取當天的零點時間戳
     *
     * @return 當天的零點時間戳
     */
    public static long getTodayStartTime() {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(new Date());
        calendar.set(Calendar.HOUR_OF_DAY, 0);
        calendar.set(Calendar.MINUTE, 0);
        calendar.set(Calendar.SECOND, 0);
        return calendar.getTime().getTime();
    }