计算生日倒计时

 public static Integer getDate(LocalDateTime item){
        SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");
        // 存今天
        Calendar cToday = Calendar.getInstance();
        // 存生日
        Calendar cBirth = Calendar.getInstance();
        try {
            // 设置生日
            cBirth.setTime(myFormatter.parse(item.toString()));
        } catch (ParseException e) {
            throw new RuntimeException(e);
        }
        // 修改为本年
        cBirth.set(Calendar.YEAR, cToday.get(Calendar.YEAR));
        int days;
        if (cBirth.get(Calendar.DAY_OF_YEAR) < cToday.get(Calendar.DAY_OF_YEAR)) {
            // 生日已经过了，要算明年的了
            days = cToday.getActualMaximum(Calendar.DAY_OF_YEAR) - cToday.get(Calendar.DAY_OF_YEAR);
            days += cBirth.get(Calendar.DAY_OF_YEAR);
        } else {
            // 生日还没过
            days = cBirth.get(Calendar.DAY_OF_YEAR) - cToday.get(Calendar.DAY_OF_YEAR);
        }
        return days;
    }