java8时间有关新特性

//LocalDate、LocalTime、LocalDateTime
LocalDateTime ldt = LocalDateTime.now();
System.out.println(ldt);
//2019-08-13T22:30:11.982

LocalDateTime ldt2 = LocalDateTime.of(2015, 10, 19, 13, 22, 22);
System.out.println(ldt2);
//2015-10-19T13:22:22

LocalDateTime ldt3 = ldt.plusYears(2);
System.out.println(ldt3);
//2021-08-13T22:30:11.982

LocalDateTime ldt4 = ldt.minusMonths(2);
System.out.println(ldt4);
//2019-06-13T22:30:11.982

System.out.println(ldt.getYear());
//2019
System.out.println(ldt.getMonthValue());
//8
System.out.println(ldt.getDayOfMonth());
//13
System.out.println(ldt.getHour());
//22
System.out.println(ldt.getMinute());
//30
System.out.println(ldt.getSecond());
//11

Instant 时间戳（以unix元年:1970年1月1日00:00:00到某个时间之间的毫秒值）

// Instant 时间戳（以unix元年:1970年1月1日00:00:00到某个时间之间的毫秒值）
Instant instant=Instant.now();
System.out.println(instant.toEpochMilli());

// Duration 用来计算两个时间之间的间隔

// Duration 用来计算两个时间之间的间隔
Instant instant=Instant.now();
Thread.sleep(1000);
Instant instant1=Instant.now();
Duration duration=Duration.between(instant,instant1);
System.out.println(duration.toMillis());
//1009

LocalTime localTime=LocalTime.now();
Thread.sleep(1000);
LocalTime localTime1= LocalTime.now();
Duration duration=Duration.between(localTime,localTime1);
System.out.println(duration.toMillis());
//1003
                

// Period 用来计算两个日期之间的间隔

LocalDate localDate = LocalDate.of(2015, 1, 1);
LocalDate localDate1 = LocalDate.now();
Period between = Period.between(localDate, localDate1);
System.out.println(between.getYears());
// 4
System.out.println(between.getMonths());
// 7
System.out.println(between.getDays());
// 12