Java日期类使用技巧

说明：

Java特有的日期类的使用

Java代码模板：

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
import java.time.Duration;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.temporal.ChronoUnit;


public class DateJudge {
    public static void main(String[] args) {

        LocalDateTime nowDateTime = LocalDateTime.of(2022, 12, 6, 12, 36,25);
        // 2.1 int getYear()：获取年份字段。
        System.out.println(nowDateTime.getYear()); //2022

        // 2.2 Month getMonth()/ int getMonthValue()：获取时间的月份。
        System.out.println(nowDateTime.getMonth()); // DECEMBER
        System.out.println(nowDateTime.getMonthValue()); //12

        // 2.3 int getDayOfMonth()：获取日期在当月中的天数。
        System.out.println(nowDateTime.getDayOfMonth()); //6

        // 2.4 DayOfWeek getDayOfWeek()：获取日期属于当前周的第几天
        System.out.println(nowDateTime.getDayOfWeek()); //TUESDAY
        System.out.println(nowDateTime.getDayOfWeek().getValue()); //2

        // 2.5  int getDayOfYear()：获取日期时间在当前年的天数。
        System.out.println(nowDateTime.getDayOfYear()); //340

        //字符串转LocalDateTime
        LocalDateTime localDateTime = LocalDateTime.parse("2021-01-28 13:12:11", DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));


        // 3.1 int getHour()：获取当前时间的小时数。
        System.out.println(nowDateTime.getHour()); //12
        // 3.2 int getMinute()：获取当前时间的分钟。
        System.out.println(nowDateTime.getMinute()); //36
        // 3.3  int getSecond()：获取当前时间秒数。
        System.out.println(nowDateTime.getSecond()); //25

        LocalDateTime tempTime = LocalDateTime.of(2021, 7, 6, 11, 36,25);
        System.out.println(tempTime); //2021-07-06T11:36:25
        System.out.println("x = 1年后的日期时间"+tempTime.plusYears(1)); //x = 1年后的日期时间2022-07-06T11:36:25
        System.out.println("x = 1月后的日期时间"+tempTime.plusMonths(1)); //x = 1月后的日期时间2021-08-06T11:36:25
        System.out.println("x = 1周后的日期时间"+tempTime.plusWeeks(1)); //x = 1周后的日期时间2021-07-13T11:36:25
        System.out.println("x = 1天后的日期时间"+tempTime.plusDays(1)); //x = 1天后的日期时间2021-07-07T11:36:25
        System.out.println("x = 1小时后的日期时间"+tempTime.plusHours(1)); //x = 1小时后的日期时间2021-07-06T12:36:25
        System.out.println("x = 1分钟后的日期时间"+tempTime.plusMinutes(1)); //x = 1分钟后的日期时间2021-07-06T11:37:25


        System.out.println("x = 1年前的日期时间"+tempTime.minusYears(1)); //x = 1年前的日期时间2020-07-06T11:36:25
        System.out.println("x = 1月前的日期时间"+tempTime.minusMonths(1)); //x = 1月前的日期时间2021-06-06T11:36:25
        System.out.println("x = 1周前的日期时间"+tempTime.minusWeeks(1)); //x = 1周前的日期时间2021-06-29T11:36:25
        System.out.println("x = 1天前的日期时间"+tempTime.minusDays(1)); //x = 1天前的日期时间2021-07-05T11:36:25
        System.out.println("x = 1小时前的日期时间"+tempTime.minusHours(1)); //x = 1小时前的日期时间2021-07-06T10:36:25
        System.out.println("x = 1分钟前的日期时间"+tempTime.minusMinutes(1)); //x = 1分钟前的日期时间2021-07-06T11:35:25


        LocalDateTime tempTime1 = LocalDateTime.of(2021, 7, 6, 11, 36,25);
        LocalDateTime tempTime2 = LocalDateTime.of(2021, 8, 6, 12, 36,25);
        // 5.1 判断tempTime1是否在tempTime2之后，是否比其更晚
        boolean after = tempTime1.isAfter(tempTime2); // false
        // 5.2 判断tempTime1是否在tempTime2之前，是否比其更早
        boolean before = tempTime1.isBefore(tempTime2); //true
        // 5.3 判断tempTime1是否与tempTime2相等
        boolean equal = tempTime1.isEqual(tempTime2); // false


        LocalDateTime changeBeforeTime = LocalDateTime.of(2021, 7, 6, 11, 36,25);
        System.out.println("修改年份后的日期" + changeBeforeTime.withYear(2022)); // 修改年份后的日期2022-07-06T11:36:25
        System.out.println("修改月份后的日期" + changeBeforeTime.withMonth(11)); // 修改月份后的日期2021-11-06T11:36:25
        System.out.println("修改当月天数后的日期" + changeBeforeTime.withDayOfMonth(11)); // 修改当月天数后的日期2021-07-11T11:36:25
        System.out.println("修改当年天数后的日期" + changeBeforeTime.withDayOfYear(11)); // 修改当年天数后的日期2021-01-11T11:36:25
        System.out.println("修改小时后的日期" + changeBeforeTime.withHour(10)); // 修改小时后的日期2021-07-06T10:36:25
        System.out.println("修改分钟.秒后的日期" + changeBeforeTime.withMinute(10).withSecond(10)); //修改分钟.秒后的日期2021-07-06T11:10:10






        LocalDateTime beginTime = LocalDateTime.of(2021, 7, 6, 11, 36,25);
        LocalDateTime endTime = LocalDateTime.of(2021, 9, 8, 01, 56,25);
        // 相差的年份数
        long betweenYears = ChronoUnit.YEARS.between(beginTime, endTime);
        System.out.println(betweenYears);  // 0
        // 相差的月份数
        long betweenMonths = ChronoUnit.MONTHS.between(beginTime, endTime);
        System.out.println(betweenMonths);  // 2
        // 相差的天数
        long betweenDays = ChronoUnit.DAYS.between(beginTime, endTime);
        System.out.println(betweenDays);  // 63
        // 相差的小时数
        long betweenHours = ChronoUnit.HOURS.between(beginTime, endTime);
        System.out.println(betweenHours); //1526
        // 相差的分钟数
        long betweenMinutes = ChronoUnit.MINUTES.between(beginTime, endTime);
        System.out.println(betweenMinutes);//91580
        // 相差的秒钟数
        long betweenMillis = ChronoUnit.MILLIS.between(beginTime, endTime);
        System.out.println(betweenMillis);//91580




        Duration between1 = Duration.between(beginTime, endTime);
        System.out.println(between1.toDays()); // 63
        System.out.println(between1.toHours()); //1526 (63天*24小时+(24+1-11)不是整天的小时数)
        System.out.println(between1.toMinutes()); // 91580 (1526小时*60分钟+（56-25）分钟外相差的秒数)
        System.out.println(between1.toMillis()); // 5494800000

    }

}