根据出生日期计算年龄

import org.junit.Test;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class JunitAge {

    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");

    @Test
    public void testAge()throws Exception{

        int  age = getAge(format.parse("1993-06-27"));
        System.out.println(age);

    }

    //由出生日期获得年龄
    public  int getAge(Date birthDay) throws Exception {
        int age = 0;
        Calendar cal = Calendar.getInstance();
        if (cal.before(birthDay)) {
           return age;
        }
        int yearNow = cal.get(Calendar.YEAR);
        int monthNow = cal.get(Calendar.MONTH);
        int dayNow = cal.get(Calendar.DAY_OF_MONTH);
        cal.setTime(birthDay);

        int yearBirth = cal.get(Calendar.YEAR);
        int monthBirth = cal.get(Calendar.MONTH);
        int dayBirth = cal.get(Calendar.DAY_OF_MONTH);
        //年相减
        age = yearNow - yearBirth;
        //判断月份
        if (monthNow <= monthBirth) {
            if (monthNow == monthBirth) {
                //判断天
                if (dayNow < dayBirth){
                    age--;
                }
            }else{
                age--;
            }
        }
        return age;
    }
}

https://blog.youkuaiyun.com/qinxu0611/article/details/86146108 

js中：

<script type="text/javascript">
    var csrq = '1995-10-07';
    var age = '';
    var d = new Date();
    var year = d.getFullYear();
    var month = d.getMonth() + 1;
    var day = d.getDate();
    if (month < 10) {
        month = '0'+month;
    }
    if(day < 10){
        day = '0'+day;
    }
    var now = year+'-'+month+'-'+day;
    if (now.substring(0,4) >= csrq.substring(0,4) && now.substring(5,7) >=csrq.substring(5,7) 
        && now.substring(8,10)>=csrq.substring(8,10)) {
        age = year - parseInt(csrq.substring(0,4));
    }else{
        age = year - parseInt(csrq.substring(0,4)) - 1;
    }
    //alert(age);
</script>