ZoneId id = ZoneId.systemDefault();LocalDateTime dateTime = LocalDateTime.now(id);System.out.println("时区ID："+id);System.out.println("当前时间："+dateTime);LocalDateTime addYear = dateTime.plus(1, ChronoUnit.YEARS);System.out.println("当前时间加1年："+addYear);LocalDateTime addDay = dateTime.plusDays(56);System.out.println("距56天后是几号："+addDay);System.out.println("从默认时区的系统获取当前日期时间："+ZonedDateTime.now());String now = "2018-09-01";String now1 = "2019-09-01 11:12:23";DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");DateTimeFormatter formatter1 = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");LocalDate nowTime = LocalDate.parse(now,formatter);LocalDateTime nowTime1 = LocalDateTime.parse(now1,formatter1);System.out.println("yyyy-MM-dd 字符串转时间："+nowTime);System.out.println("yyyy-MM-dd HH:mm:ss 字符串转时间："+nowTime1);Long now2 = System.currentTimeMillis();LocalDateTime date = LocalDateTime.ofEpochSecond(now2/1000,0,ZoneOffset.ofHours(8));System.out.println("时间戳转时间："+date);LocalDateTime startDateTime = LocalDateTime.of(2018,9,19,23,34,12);LocalDateTime endDateTime = LocalDateTime.of(2018,9,15,4,34,12);System.out.println("手动构造开始时间："+startDateTime);System.out.println("手动构造结束时间："+endDateTime);Duration duration = Duration.between(endDateTime,startDateTime);System.out.printf("时间1,时间2相差:%s天%n",duration.toDays());System.out.printf("时间1,时间2相差:%s分钟%n",duration.toMinutes());LocalDate startDate = LocalDate.of(2018,10,19);LocalDate endDate = LocalDate.of(2018,9,15);Period period = Period.between(endDate,startDate);System.out.printf("日期1,日期2相差:%s天%n",period.getDays());System.out.println("本月有多少天："+YearMonth.now().lengthOfMonth());System.out.println("今年有多少天："+YearMonth.now().lengthOfYear());