java 由出生日期获得年龄

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Date;

/**

*

* @title: GetAgeByBirthday

*

* @description: 由出生日期获得年龄

*/

public class GetAgeByBirthday {

public static void main(String[] args) throws Exception {

SimpleDateFormat s = new SimpleDateFormat("yyyy/MM/dd");

Date date = s.parse("1995/6/7");

int age = getAge(date);

System.out.println(age);

System.exit(0);

}

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;

}

}