java新时间类

时间

java8以前使用的时间很多方法都已经废弃了，而且不是线程安全的，java8提供了一系列的时间类，这些时间类都是线程安全的

LocalDate、LocalTime、LocalDateTime

这三个关于时间的类在使用上都类似

/**	 * LocalDate	 */@Testpublic void test1() {  LocalDate date1 = LocalDate.now();  System.out.println(date1);//2020-03-30  LocalDate plusYears = date1.plusYears(1);  System.out.println(plusYears);//2021-03-30  LocalDate minusDays = date1.minusDays(2);  System.out.println(minusDays);//2020-03-28  LocalDate date2 = LocalDate.of(2019, 3, 30);  System.out.println(date2.getYear());//2019}/**	 * LocalTime	 */@Testpublic void test2() {  LocalTime now = LocalTime.now();  System.out.println(now);//21:15:23.418  int minute = now.getMinute();  System.out.println(minute);//15  int second = now.getSecond();  System.out.println(second);//23  LocalTime of = LocalTime.of(10, 10, 10);  System.out.println(of);//10:10:10  LocalTime minusMinutes = of.minusMinutes(2);  System.out.println(minusMinutes);//10:08:10  LocalTime plusHours = of.plusHours(2);  System.out.println(plusHours);//12:10:10}/**	 * LocalDateTime	 */@Testpublic void test3() {  LocalDateTime now = LocalDateTime.now();  System.out.println(now);//2020-03-30T21:20:37.961  int minute = now.getMinute();  System.out.println(minute);//20  LocalDateTime plusMinutes = now.plusMinutes(20);  System.out.println(plusMinutes);//2020-03-30T21:40:37.961  LocalDateTime minusYears = now.minusYears(2);  System.out.println(minusYears);//2018-03-30T21:20:37.961  LocalDateTime of = LocalDateTime.of(2021, 3, 30, 21, 19, 50);  System.out.println(of);//2021-03-30T21:19:50}

时间戳

/**	 * Instant	 */@Testpublic void test4() {  Instant now = Instant.now();  System.out.println(now);//2020-03-30T13:26:10.640Z  Instant plusSeconds = now.plusSeconds(10);  System.out.println(plusSeconds);//2020-03-30T13:26:20.640Z  //获取时间戳相对于1970年0时0分0秒的毫秒数  long epochMilli = plusSeconds.toEpochMilli();  System.out.println(epochMilli);//1585574780640}

Duration获取时间间隔

/**	 * Duration	 */@Testpublic void test5() {  Instant start = Instant.now();  Instant end = start.plusSeconds(10);  Duration duration = Duration.between(start, end);  long seconds = duration.getSeconds();  //获取时间间隔的秒数  System.out.println(seconds);//10  //获取时间间隔的毫秒数  long millis = duration.toMillis();  System.out.println(millis);//10000}

Peroid获取日期间隔

@Testpublic void test6() {  LocalDate date1 = LocalDate.now();  LocalDate date2 = date1.plusYears(2);  Period period = Period.between(date1, date2);  //获取两时间间隔的月数,指两个月份的间隔数，并不是时间间隔的总月数  int months = period.getMonths();  System.out.println(months);//0}

TemporalAdjuster矫正日期

@Testpublic void test7() {  LocalDate date1 = LocalDate.now();  System.out.println(date1);//2020-03-31  //TemporalAdjusters类中封装了一些常用地时间矫正方法  TemporalAdjuster next = TemporalAdjusters.next(DayOfWeek.FRIDAY);  LocalDate date2 = date1.with(next);  System.out.println(date2);//2020-04-03  //自定义时间矫正器  LocalDate date3 = date1.with(x->{    LocalDate ld=(LocalDate)x;    DayOfWeek dayOfWeek = ld.getDayOfWeek();    if(dayOfWeek.equals(DayOfWeek.FRIDAY)) {      return ld.plusDays(3);    }else if(dayOfWeek.equals(DayOfWeek.SATURDAY)) {      return ld.plusDays(2);    }else {      return ld.plusDays(1);    }  });  System.out.println(date3);//2020-04-01}

由于TemporalAdjuster是一个函数式接口，所以我们可以使用lambda表达式自定义矫正规则

@FunctionalInterfacepublic interface TemporalAdjuster {  Temporal adjustInto(Temporal temporal);}

DateTimeFormatter格式化日期时间

@Testpublic void test8() {  LocalDateTime dateTime1 = LocalDateTime.now();  System.out.println(dateTime1);//2020-03-31T18:28:04.256  DateTimeFormatter formatter1 = DateTimeFormatter.ISO_DATE;  String format1 = dateTime1.format(formatter1);  System.out.println(format1);//2020-03-31  DateTimeFormatter formatter2 = DateTimeFormatter.ofPattern("yyyy年MM月dd日HH时mm分ss秒");  String format2 = dateTime1.format(formatter2);  System.out.println(format2);//2020年03月31日18时28分04秒  LocalDateTime dateTime2 = LocalDateTime.parse(format2, formatter2);  System.out.println(dateTime2);//2020-03-31T18:28:04}

ZoneDate

@Testpublic void test9() {  //获取可用时区  ZoneId.getAvailableZoneIds().forEach(System.out::println);  LocalDate date1 = LocalDate.now(ZoneId.of("Asia/Tokyo"));  System.out.println(date1);//2020-03-31}

ZoneTime

@Testpublic void test10() {  LocalTime time1 = LocalTime.now(ZoneId.of("Asia/Tokyo"));  System.out.println(time1);//19:44:15.228  OffsetTime atOffset = time1.atOffset(ZoneOffset.ofHours(2));  System.out.println(atOffset);//19:44:15.228+02:00}

ZoneDateTime

@Testpublic void test11() {  LocalDateTime dateTime1 = LocalDateTime.now(ZoneId.of("Asia/Shanghai"));  System.out.println(dateTime1);//2020-03-31T18:51:07.136  ZonedDateTime atZone = dateTime1.atZone(ZoneId.of("Asia/Shanghai"));  System.out.println(atZone);//2020-03-31T18:51:07.136+08:00[Asia/Shanghai]	+09:00表示时间比格林尼治时间快9小时}