根据身份证号判断性别、年龄、生日

根据身份证号判断证件持有人的性别、年龄、生日。废话不多说，直接上代码。

public class IdentifyCard {
    private static final Integer[] ODD_NUMS = {1, 3, 5, 7, 9};
    private static final Integer[] EVEN_NUMS = {0, 2, 4, 6, 8};

    private static final ThreadLocal<SimpleDateFormat> DATE_FORMAT_THREAD_LOCAL =
            ThreadLocal.withInitial(() -> new SimpleDateFormat("yyyyMMdd"));
    
    /**
     * @param area     地区码，如：110101
     * @param birthday 出生日期：20000101
     * @param sex      性别：0=男；1=女
     * @param size     最小1；最大500
     * @return results 生成结果集
     */
    public static String[] generator(String area, Date birthday, int sex, int size) {
        SexEnum.checkSex(sex);
        checkSize(size);
        List<String> resultList = new ArrayList<>(size);
        String simpleBirthday = DATE_FORMAT_THREAD_LOCAL.get().format(birthday);
        Set<String> numbers = ordinalNumbers(sex, size);
        for (String seqNo : numbers) {
            String prefix = area + simpleBirthday + seqNo;
            String cardNo = prefix + getCheckCode(prefix);
            resultList.add(cardNo);
        }
        String[] results = resultList.toArray(new String[size]);
        new RandomSort<String>(results).changePosition();
        return results;
    }

    private static void checkSize(int size) {
        if (size < 1 || size > 500) {
            throw new IllegalArgumentException("The size min 1, max 500.");
        }
    }

    // prefix = area + birthdayFormat + seqNo
    private static String getCheckCode(String prefix) {
        int sum = 0;
        for (int i = 0; i < prefix.length(); i++) {