java进阶 JDK7 -日期48

package com.cyjt97.dt;

import java.util.Date;

public class day {
    public static void main(String[] args) {
        Date dt = new Date();
        Date dt2 = new Date(0L);
        System.out.println(dt);//Sat Mar 18 16:09:15 CST 2023
        System.out.println(dt2);//Thu Jan 01 08:00:00 CST 1970

        System.out.println(dt.getTime());//1679127078299
        System.out.println(dt2.getTime());//0

    }
}

package com.cyjt97.dt;

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

public class day2 {
    public static void main(String[] args) throws ParseException {
//        创建日期格式化对象，封装时间
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat();
        //        手动修改
        SimpleDateFormat simpleDateFormat2 = new SimpleDateFormat("yyyy年MM月dd日  HH:mm:ss");

//        创建date对象，封装时间
        Date date = new Date();
//        将日期时间转为字符串
        String res =simpleDateFormat.format(date);
        String res2 =simpleDateFormat2.format(date);
        System.out.println(res);//2023/3/18 下午4:58
        System.out.println(res2);//2023年03月18日  17:41:01


        String today = "2023年3月18日";
        SimpleDateFormat simpleDateFormat1 = new SimpleDateFormat("yyyy年MM月dd日");
        Date date2 = simpleDateFormat1.parse(today);
        System.out.println(date2);//Sat Mar 18 00:00:00 CST 2023
        
        
        

    }
}

package com.cyjt97.dt;

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

public class day3 {
    public static void main(String[] args) throws ParseException {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入您的生日");
        String b = sc.nextLine();
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy年MM月dd日");
        Date bb = simpleDateFormat.parse(b);
        Date TODAY = new Date();
        long time =   TODAY.getTime()-bb.getTime();
        System.out.println(time/1000/60/60/24);

    }
}