Java根据身份证号获取年龄

/**
     * 根据身份证号获取年龄
     *
     * @param idNumber 身份证号
     * @return 年龄
     */
    private static int calculateAge(String idNumber) {
        int birthYear = Integer.parseInt(idNumber.substring(6, 10));
        int birthMonth = Integer.parseInt(idNumber.substring(10, 12));
        int birthDay = Integer.parseInt(idNumber.substring(12, 14));
        Calendar currentCalendar = Calendar.getInstance();
        int currentYear = currentCalendar.get(Calendar.YEAR);
        int currentMonth = currentCalendar.get(Calendar.MONTH) + 1;
        int currentDay = currentCalendar.get(Calendar.DAY_OF_MONTH);
        int age = currentYear - birthYear;
        if (birthMonth > currentMonth || (birthMonth == currentMonth && birthDay > currentDay)) {
            age--;
        }
        return age;
    }