Java中根据出生日期计算当前年龄大小

package com.common.utils;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class AgeUtil {
    public static  Date parse(String strDate) throws ParseException {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        return sdf.parse(strDate);
    }
    //由出生日期获得年龄
    public static  int getAge(Date birthDay) throws Exception {
        Calendar cal = Calendar.getInstance();
        if (cal.before(birthDay)) {
            throw new IllegalArgumentException(
                    "The birthDay is before Now.It's unbelievable!");
        }
        int yearNow = cal.get(Calendar.YEAR);
        int monthNow = cal.get(Calendar.MONTH);
        int dayOfMonthNow = cal.get(Calendar.DAY_OF_MONTH);
        cal.setTime(birthDay);

        int yearBirth = cal.get(Calendar.YEAR);
        int monthBirth = cal.get(Calendar.MONTH);
        int dayOfMonthBirth = cal.get(Calendar.DAY_OF_MONTH);

        int age = yearNow - yearBirth;

        if (monthNow <= monthBirth) {
            if (monthNow == monthBirth) {
                if (dayOfMonthNow < dayOfMonthBirth) age--;
            }else{
                age--;
            }
        }
        return age;
    }

    public static void main(String args[]) {
        try {
            int  age = getAge(parse("1993-4-24"));
            System.out.println("age=="+age);
        } catch (ParseException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }


    }
}