JAVA基础知识时间总结

大家有什么问题或者意见可以在评论区回复。欢迎大家一起讨论学习。新的时间类型LocalDateTime,OffsetDateTime,LocalDate//截取到日、时.HOURS));//输出2020-05-06T00:002020-05-06T13:00//设置小时为14点System.out.println(LocalDateTime.now().withHour(14));//减去12天System.out.println(LocalDateTime.now().minusDays(12));//加12小时System.out.println(LocalDateTime.now().plusHours(12));//设置0时区时间，截取到全天，设置12点OffsetDateTime.now(ZoneOffset.of("+00:00")).truncatedTo(ChronoUnit.DAYS).withHour(12)//获取上海时区时间OffsetDateTime.now(ZoneId.of("Asia/Shanghai"))//实时转换LocalDateloc=LocalDate.parse("2020-01-02");System.out.println(loc);DateTimeFormatterusDateformatter=DateTimeFormatter.ofPattern("MM-dd-yyyy");System.out.println(usDateformatter.format(loc));//输出2020-01-0201-02-2020//当parse的格式不是本地时间格式时，需要使用对应的formatterformatLocalDatenewDate=LocalDate.parse("07-04-2020",usDateformatter);System.out.println(newDate);//输出2020-07-04旧版本时间类型Calendar,DateCalendarcal=Calendar.getInstance();cal.set(2020,1,26);Datedate=cal.getTime();System.out.println(date);//输出WedFeb2622:01:51CST2020cal.add(Calendar.DAY_OF_MONTH,7);System.out.println(cal.getTime());//输出WedMar0422:01:51CST2020新增时间类型Instant不可变System.out.println(Instant.MIN);System.out.println(Instant.now());System.out.println(Instant.MAX);//输出-1000000000-01-01T00:00:00Z2020-05-17T14:10:23.739Z+1000000000-12-31T23:59:59.999999999ZDuration，包括toDays()、toHours()、toMinutes()、toNanos()等方法，minus()减去，加上增加，multipliedBy乘以Instantstart=Instant.now();Thread.sleep(1);Instantend=Instant.now();Durationduration=Duration.between(start,end);longmillionSeconds=duration.toMillis();System.out.println(millionSeconds);//输出1LocalDateTemporalAdjusters中包含的方法：firstDayOfMonth,lastDayOfMonth,firstDayOfYear,lastDayOfYear,firstDayOfNextDath,firstDayOfNext.MonOffirstInMonth(DAYOfSUNOfFirstInMonth(yOfWeek.SUNDAY),dayOfWeekInMonth(2,DayOfWeek.SUNDAY)next(DayOfWeek.SUNDAY),nextOrSame(DayOfWeek.SUNDAY),previous(DayOfWeek.SUNDAY),previousOrSame(DayOfWeek.SUNDAY)LocalDate现在=LocalDate。dateOfBirth=LocalDate.of(1987,Month.NOVEMBER,23);System.out.println(dateOfBirth);System.out.println(now);//输出1987-11-232020-05-18Periodp=dateOfBirth.until(now);System.out.println("Years:"+p.getYears());//输出Years:32Longdays=dateOfBirth.until(now,ChronoUnit.DAYS);System.out.println("Days:"+days);//OutputDays:11865//月份差距只是余数，不是和上面一样的月数，而是去掉差后的月数System.out.println(p.get(ChronoUnit.YEARS));System.out.println(p.get(ChronoUnit.MONTHS));//输出325LocalDatenextSunday=LocalDate.now().with(TemporalAdjusters.next(DayOfWeek.SUNDAY));System.out.println(nextSunday);//输出2020-05-24LocalTimeLocalTimelocalTime=LocalTime.now();System.out.println(localTime);System.out.println(localTime.plusHours(8));System.out.println(LocalTime.of(20,10));//输出20:28:59.82304:30:25.36720:10ZonedDateTimeSetallZoneIds=ZoneId.getAvailableZoneIds();for(StringzoneId:allZoneIds){if(zoneId.contains("America")){System.out.println(zoneId);}}//输出很多暂停时间ZoneIdukTZ=ZoneId.of("Asia/Shanghai");System.out.println(ukTZ);ZonedDateTimecurrentMetting=ZonedDateTime.of(LocalDate.of(2020,Month.JUNE,18),LocalTime.of(10,0),ZoneId.of("亚洲/上海"));ZonedDateTimenextMetting=currentMetting.plus(Period.ofMonths(1));ZonedDateTimenextUsMeeting=nextMetting.withZoneSameInstant(ZoneId.of("美国/New_York"));System.out.println(currentMetting);System.out.println(nextMetting);System.out.println(nextUsMeeting);//输出2020-06-18T10:00+08:00[亚洲/上海]2020-07-18T10:00+08:00[亚洲/上海]2020-07-17T22:00-04:00[美国/纽约]DateTimeFormatterSystem.out.println("ISO_DATE_TIME="+DateTimeFormatter.ISO_DATE_TIME.format(currentMetting));System.out.println("RFC_1123_DATE_TIME="+DateTimeFormatter.RFC_1123_DATE_TIME.format(currentMetting));//输出ISO_DATE_TIME=2020-06-18T10:00:00+08:00[Asia/Shanghai]RFC_1123_DATE_TIME=Thu,18Jun202010:00:00+0800旧版本时间和新版本时间转换Instantinstant=Instant.now();Datedate=Date.from(instant);instant=date.toInstant();Timestamptimestamp=Timestamp.from(instant);instant=timestamp.toInstant();