1 package Joker;
2 import java.text.SimpleDateFormat;
3 import java.time.Year;
4 import java.util.Calendar;
5 import java.util.Date;
6 /*
7 * Date
8 * 日期类
9 * 1970.1.1 0:00:00毫秒数
10 * UTC
11 * GMT
12 * java.util.Date
13 * setTime()
14 * getTime()
15 *
16 * SimpleDateFormat
17 * java.text.SimpleDateFormat
18 * 用来格式化(Date——String)和解析(String——Date)的类
19 * String Foramt(Date d):格式化
20 * Date Parse(String s):解析
21 *
22 * Calendar
23 *
24 */
25 public class xxx {
26 public static void main(String[] args) {
27 Date a=new Date();//当前系统时间
28 System.out.println(a);
29 long time=a.getTime();
30 //long getTime();//获取对象的毫秒数
31 System.out.println(time);
32 a.setTime(1823279);
33 //void setTime(long num);设定时间为Long num对应的时间
34 System.out.println(a);
35 long xxx=(2021-2001+1);
36 System.out.println(xxx);
37 //time-=24*60*60*1000-12*60*60*1000-38*60*1000-27*1000;
38 a.setTime(time);
39 System.out.println(a);
40 //SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
41 //String s=sdf.format(a);
42 System.out.println(a);
43 //System.out.println(s);
44 //String st="2021-04-22 12:27:30";
45 //a=sdf.parse(st);
46 System.out.println(a);
47 //前1t12h38min27s
48 a.setTime(time);
49 System.out.println(a);
50 SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
51 String st=sdf.format(a);
52 System.out.println(st);
53
54 Calendar cal=Calendar. getInstance();
55 //set:设置时间分量
56 //get:获取时间分量
57 System.out.println(cal.get(Calendar.DAY_OF_WEEK));
58 //add(1,2)
59 cal.add(Calendar.YEAR,1);
60 System.out.println(cal);
61 a=cal.getTime();
62 System.out.println(a);
63 }
64 }
1 package Joker;
2 import java.text.SimpleDateFormat;
3 import java.util.Date;
4 /**
5 * 根据当前日期获得昨天的当前日期
6 * @author Wakk
7 *
8 */
9 public class Biu {
10 public static void main (String[] args) {
11 // 时间日期格式化
12 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
13 // 获取当前日期
14 Date today = new Date();
15 System.out.println(today);
16 System.out.println(sdf.format(today));
17 System.out.println("============================================");
18 // 根据当前日期获取昨天的当前日期
19 Date yesterday = new Date(new Date().getTime() - 86400000L);
20 System.out.println(yesterday);
21 System.out.println(sdf.format(yesterday));
22 }
23 }
1 package Joker;
2 import java.text.SimpleDateFormat;
3 import java.util.Date;/*
4 * Date
5 * 日期类
6 * 1970.1.1 0:00:00毫秒数
7 * UTC
8 * GMT
9 * java.util.Date
10 * setTime()
11 * getTime()
12 *
13 * SimpleDateFormat
14 * java.text.SimpleDateFormat
15 * 用来格式化(Date——String)和解析(String——Date)的类
16 * String Foramt(Date d):格式化
17 * Date Parse(String s):解析
18 *
19 */
20 public class xxx {
21 public static void main(String[] args) {
22 Date a=new Date();//当前系统时间
23 System.out.printl
1 package Joker;
2 import java.text.SimpleDateFormat;
3 import java.util.Date;/*
4 * Date
5 * 日期类
6 * 1970.1.1 0:00:00毫秒数
7 * UTC
8 * GMT
9 * java.util.Date
10 * setTime()
11 * getTime()
12 *
13 * SimpleDateFormat
14 * java.text.SimpleDateFormat
15 * 用来格式化(Date——String)和解析(String——Date)的类
16 * String Foramt(Date d):格式化
17 * Date Parse(String s):解析
18 *
19 */
20 public class xxx {
21 public static void main(String[] args) {
22 Date a=new Date();//当前系统时间
23 System.out.println(a);
24 long time=a.getTime();
25 //long getTime();//获取对象的毫秒数
26 System.out.println(time);
27 a.setTime(1823279);
28 //void setTime(long num);设定时间为Long num对应的时间
29 System.out.println(a);
30 long xxx=(2021-2001+1);
31 System.out.println(xxx);
32 //time-=24*60*60*1000-12*60*60*1000-38*60*1000-27*1000;
33 a.setTime(time);
34 System.out.println(a);
35 //SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
36 //String s=sdf.format(a);
37 System.out.println(a);
38 //System.out.println(s);
39 //String st="2021-04-22 12:27:30";
40 //a=sdf.parse(st);
41 System.out.println(a);
42 //前1t12h38min27s
43 a.setTime(time);
44 System.out.println(a);
45 SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
46 String st=sdf.format(a);
47 System.out.println(st);
48 }
49 }
n(a);
24 long time=a.getTime();
25 //long getTime();//获取对象的毫秒数
26 System.out.println(time);
27 a.setTime(1823279);
28 //void setTime(long num);设定时间为Long num对应的时间
29 System.out.println(a);
30 long xxx=(2021-2001+1);
31 System.out.println(xxx);
32 //time+=24L*60*1000
33 a.setTime(time);
34 System.out.println(a);
35 SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
36 String s=sdf.format(a);
37 System.out.println(a);
38 System.out.println(s);
39 String st="2021-04-22 12:27:30";
40 a=sdf.parse(st);
41 System.out.println(a);
42 //前1t12h38min27s
43
44 }
45 }