package com.fjut.util;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* 时间工具类
* @author LGX
*
*/
public class DateUtil {
public static int getAgeByBirth(Date birthday) {
//Calendar：日历
/*从Calendar对象中或得一个Date对象*/
Calendar cal = Calendar.getInstance();
/*把出生日期放入Calendar类型的bir对象中，进行Calendar和Date类型进行转换*/
Calendar bir = Calendar.getInstance();
bir.setTime(birthday);
/*如果生日大于当前日期，则抛出异常：出生日期不能大于当前日期*/
if(cal.before(bir)){
throw new IllegalArgumentException("The birthday is before Now,It's unbelievable");
}
/*取出当前年月日*/
int yearNow = cal.get(Calendar.YEAR);
int monthNow = cal.get(Calendar.MONTH);
int dayNow = cal.get(Calendar.DAY_OF_MONTH);
/*取出出生年月日*/
int yearBirth = bir.get(Calendar.YEAR);
int monthBirth = bir.get(Calendar.MONTH);
int dayBirth = bir.get(Calendar.DAY_OF_MONTH);
/*大概年龄是当前年减去出生年*/
int age = yearNow - yearBirth;
/*如果出当前月小与出生月，或者当前月等于出生月但是当前日小于出生日，那么年龄age就减一岁*/
if(monthNow < monthBirth || (monthNow == monthBirth && dayNow < dayBirth)){
age--;
}
return age;
}
/**
* 日期格式化
* @param date
* @return
*/
public static String dateFormate(Date date) {
SimpleDateFormat sim = new SimpleDateFormat("yyyy-MM-dd");
return sim.format(date);
}
/**
* 日期格式化
* @param date
* @return
*/
public static String dateFormate2(Date date) {
SimpleDateFormat sim = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
return sim.format(date);
}
public static void main(String[] args) throws Exception {
// SimpleDateFormat sim = new SimpleDateFormat("yyyy-MM-dd");
// Date date = sim.parse("1997-11-16");
// int year = getAgeByBirth(date);
// System.out.println(year);
System.out.println(dateFormate(new Date()));
}
}
