learning java java.time相关类

        var clock = Clock.systemUTC();
        System.out.println(clock.instant());
        System.out.println(clock.millis());
        System.out.println(System.currentTimeMillis());
        System.out.println(clock.getZone());

        var d  = Duration.ofSeconds();
        System.out.println(d.toDays());
        System.out.println(d.toMinutes());
        System.out.println(d.toHours());

        var clock2 = Clock.offset(clock,d);
        System.out.println(clock2.instant());

        var instant = Instant.now();

        System.out.println(instant);

        var instant2  =  instant.plusSeconds();
        System.out.println(instant2);

        System.out.println(instant.getEpochSecond());
        System.out.println(instant2.getEpochSecond());

        var instant3 = Instant.parse("2014-02-23T10:12:35.342Z");
        var instant4 = instant3.plus(Duration.ofHours().plusMinutes());
        System.out.println(instant4);

        var instant5 = instant4.minus(Duration.ofDays());

        var localDate = LocalDate.now();
        System.out.println(localDate);

        localDate = LocalDate.ofYearDay(,);
        System.out.println(localDate);

        localDate = LocalDate.of(, Month.MAY,);
        System.out.println(localDate);

        var localTime = LocalTime.now();
        System.out.println(localTime);

        localTime = LocalTime.of(,);
        System.out.println(localTime);

        localTime = LocalTime.ofSecondOfDay();
        System.out.println(localTime);

        var localDateTime = LocalDateTime.now();
        System.out.println(localDateTime);
        var future = localDateTime.plusHours().plusMinutes();
        System.out.println(future);

        var year = Year.now();
        System.out.println(year);

        year = year.plusYears();
        System.out.println(year);

        var ym = year.atMonth();
        System.out.println(ym);

        var md = MonthDay.now();
        System.out.println(md);

        var md2 = md.with(Month.MAY).withDayOfMonth();
        System.out.println(md2);

output:

2019-07-26T01:41:36.385911400Z
1564105296390
1564105296390
Z
0
100
1
2019-07-26T03:21:36.390898600Z
2019-07-26T01:41:36.390898600Z
2019-07-26T03:21:36.390898600Z
1564105296
1564111296
2014-02-23T15:16:35.342Z
2019-07-26
2014-05-26
2014-05-21
09:41:36.406855600
23:23
01:31:43
2019-07-26T09:41:36.406855600
2019-07-27T10:44:36.406855600
2019
2024
2024-10
--07-26
--05-23