java根据身份证算年龄

可以通过以下代码实现根据身份证号码计算年龄：

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class AgeCalculator {

    public static void main(String[] args) {
        String idCard = "身份证号码";
        int age = getAgeByIdCard(idCard);
        System.out.println("年龄：" + age);
    }

    public static int getAgeByIdCard(String idCard) {
        try {
            String birthdayStr = idCard.substring(6, 14);
            SimpleDateFormat format = new SimpleDateFormat("yyyyMMdd");
            Date birthday = format.parse(birthdayStr);
            Calendar cal = Calendar.getInstance();
            if (cal.before(birthday)) { // 出生日期晚于当前时间，无法计算
                throw new IllegalArgumentException("The birthDay is before Now.It's unbelievable!");
            }
            int yearNow = cal.get(Calendar.YEAR);
            int monthNow = cal.get(Calendar.MONTH) + 1;
            int dayOfMonthNow = cal.get(Calendar.DAY_OF_MONTH);
            cal.setTime(birthday);
            int yearBirth = cal.get(Calendar.YEAR);
            int monthBirth = cal.get(Calendar.MONTH) + 1;
            int dayOfMonthBirth = cal.get(Calendar.DAY_OF_MONTH);
            int age = yearNow - yearBirth;
            if (monthNow < monthBirth || (monthNow == monthBirth && dayOfMonthNow < dayOfMonthBirth)) {
                age--;
            }
            return age;
        } catch (ParseException e) {
            e.printStackTrace();
            return 0;
        }
    }
}

将其中的“身份证号码”替换为实际的身份证号码即可得到该身份证号码对应的年龄。