[java8新特性]
LocalDate:获取日期
LocalTime:获取时间
LocalDateTime:获取日期+时间
学会LocalDateTime，其余两个都类似，基本都学会。
LocalDateTime localDateTime = LocalDateTime.now();
System.out.println(localDateTime); // 获取当前时间:2019-01-24T13:16:07.126
System.out.println(localDateTime.getYear()); // 年：2019
System.out.println(localDateTime.getMonthValue());// 月：1
System.out.println(localDateTime.getMonth()); // 月：JANUARY
System.out.println(localDateTime.getDayOfMonth());// 日：24
System.out.println(localDateTime.getHour()); // 小时：13
System.out.println(localDateTime.getMinute()); // 分钟：24
System.out.println(localDateTime.getSecond()); // 秒：5
System.out.println(localDateTime.getDayOfWeek()); // 星期：THURSDAY
System.out.println(localDateTime.getNano()); // 纳秒：216000000
System.out.println(localDateTime.getDayOfYear()); // 一年的第几天：24
System.out.println(localDateTime.getLong(ChronoField.YEAR)); // 获取指定字段值：2019
// 2019-01-24T13:24:05
System.out.println(LocalDateTime.of(2019, 01, 24, 13, 24, 5));
// 2019-01-24T13:24:05
System.out.println(LocalDateTime.of(2019, Month.JANUARY, 24, 13, 24, 5));
// 2019-01-24T13:55:04.479
System.out.println(LocalDateTime.of(LocalDate.now(), LocalTime.now()));
// 2019-01-24T13:24
System.out.println(LocalDateTime.of(2019, 01, 24, 13, 24));
// 2019-01-24T13:24
System.out.println(LocalDateTime.of(2019, Month.JANUARY, 24, 13, 24));
// 2019-01-24T13:24:05.216
System.out.println(LocalDateTime.of(2019, 01, 24, 13, 24, 5,216000000));
// 2019-01-24T13:24:05.216
System.out.println(LocalDateTime.of(2019, Month.JANUARY, 24, 13, 24, 5,216000000));
// 加时间
System.out.println(localDateTime.plusYears(02)); // 年：加2年 2021-01-24T13:55:04.477
System.out.println(localDateTime.plusMonths(02)); // 月：加2月 2019-03-24T13:55:04.477
System.out.println(localDateTime.plusDays(02)); // 天：加2天 2019-01-26T13:55:04.477
System.out.println(localDateTime.plusHours(02)); // 时：加2时 2019-01-24T15:55:04.477
System.out.println(localDateTime.plusMinutes(02)); // 分：加2分 2019-01-24T13:57:04.477
System.out.println(localDateTime.plusSeconds(02)); // 秒：加2秒 2019-01-24T13:55:06.477
System.out.println(localDateTime.plusWeeks(02)); // 周：加2周 2019-02-07T13:55:04.477
System.out.println(localDateTime.plusNanos(02)); // 纳秒：加2纳秒 2019-01-24T13:55:04.477000002
// 减时间
System.out.println(localDateTime.minusYears(02)); // 年：减2年 2017-01-24T14:07:37.032
System.out.println(localDateTime.minusMonths(02)); // 月：减2月 2018-11-24T14:07:37.032
System.out.println(localDateTime.minusDays(02)); // 天: 减2天 2019-01-22T14:07:37.032
System.out.println(localDateTime.minusHours(02)); // 时：减2时 2019-01-24T12:07:37.032
System.out.println(localDateTime.minusMinutes(02)); // 分：减2分 2019-01-24T14:05:37.032
System.out.println(localDateTime.minusSeconds(02)); // 秒：减2秒 2019-01-24T14:07:35.032
System.out.println(localDateTime.minusWeeks(02)); // 周：减2周 2019-01-10T14:07:37.032
System.out.println(localDateTime.minusNanos(02)); // 纳秒：减2纳秒 2019-01-24T14:07:37.031999998
Instant instant = ZonedDateTime.now().toInstant();
LocalDateTime from = LocalDateTime.from(instant.atZone(ZoneId.systemDefault()));
System.out.println(from); // 2019-01-26T16:10:32.442
// LocalDateTime转localDate和localTime
LocalDate localDate = LocalDateTime.now().toLocalDate();
System.out.println(localDate); // 2019-01-26
LocalTime localTime = LocalDateTime.now().toLocalTime();
System.out.println(localTime); // 16:00:52.001
// LocalDate转LocalDateTime
LocalDateTime localDateTime = LocalDate.now().atTime(1, 1, 1);
System.out.println(localDateTime); // 2019-01-26T01:01:01
// LocalTime转LocalDateTime
LocalDateTime localDateTime1 = LocalTime.now().atDate(LocalDate.of(2019, 1, 1));
System.out.println(localDateTime1); // 2019-01-01T16:00:52.001其它特性或API，可查阅JDK1.8API或参考本人其它文章，另本人有中文版JDK1.8API可以参考我的分享文章