java进阶 JDK7 -日期 -案例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);

    }
}

　　

 

 

 

 

 

package com.cyjt97.dt;

import java.util.Calendar;

import static java.util.Calendar.*;

public class day4 {
    public static void main(String[] args) {
//        Calendar c是抽象方法
//        Calendar.getInstance()是子类对象
        Calendar c = getInstance();
//        年
        int i = c.get(YEAR);
//        月
        int i2 = c.get(MONTH);
//        日
        int i3 = c.get(DAY_OF_MONTH);
//        周
        int week = c.get(DAY_OF_WEEK);
        char weekIndex[] = {' ', '日', '一', '二', '三', '四', '五', '六'};

        System.out.println(i);
        System.out.println(i2 + 1);
        System.out.println(i3);
        System.out.println(weekIndex[week]);
//        修改年份信息
        c.set(YEAR,2022);
        System.out.println(c.get(YEAR));
//        修改年份信息
        c.set(2008,12,16);
        System.out.println(c.get(YEAR)+'年');
        System.out.println(c.get(Calendar.MONTH)+'月');
        System.out.println(c.get(DAY_OF_WEEK)+'日');
//        对年份做增减
        c.add(YEAR,-1);

    }
}

　　

 

 

package com.cyjt97.dt;

import java.util.Calendar;

import static java.util.Calendar.DAY_OF_WEEK;

public class day5 {
    public static void main(String[] args) {
        Calendar c = Calendar.getInstance();
        c.set(2023, 2, 23);
        char weekIndex[] = {' ', '日', '一', '二', '三', '四', '五', '六'};
        int week = c.get(DAY_OF_WEEK);
       if (weekIndex[week] == '四'){
           System.out.println("疯狂星期四");
       }else {
           System.out.println("not");
       }
    }
}

　　

 

 

package com.cyjt97.dt;

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

public class day6 {
    public static void main(String[] args) throws ParseException {
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入");
        String a = sc.nextLine();
        SimpleDateFormat dt = new SimpleDateFormat("yyyy年MM月dd日");
        Date date = dt.parse(a);
        Calendar c = Calendar.getInstance();
        c.setTime(date);
        int day = c.get(Calendar.DAY_OF_YEAR);
        System.out.println(day);


    }
}