Java8 API 时间类Year

Java8的时间类Year，只用来表示年，例如：2021。

import java.time.LocalDate;
import java.time.MonthDay;
import java.time.Year;
import java.time.temporal.ChronoField;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalQueries;

public class YearTest {

    public static void main(String[] args) {

        LocalDate localDate = LocalDate.of(2020,1,2);

        Year now = Year.now();
        System.out.println("now:"+now);

        //adjustInto
        System.out.println(now.adjustInto(localDate));

        //atDay
        LocalDate atDay = now.atDay(105);
        System.out.println("atDay:"+atDay);

        //atMonth
        System.out.println("atMonth:"+now.atMonth(5));

        //atMonthDay
        MonthDay monthDay = MonthDay.now();
        System.out.println("atMonthDay:"+Year.of(2010).atMonthDay(monthDay));

        //compareTo
        int i = now.compareTo(Year.of(2010));
        System.out.println("compareTo:"+i);
        i = Year.of(2010).compareTo(now);
        System.out.println("compareTo:"+i);

        //isAfter
        boolean after = now.isAfter(Year.of(2010));
        System.out.println("isAfter:"+after);

        //isBefore
        boolean before = now.isBefore(Year.of(2010));
        System.out.println("isBefore:"+before);

        //isLeap
        boolean leap = now.isLeap();
        System.out.println("isLeap:"+leap);

        //isSupported
        System.out.println("isSupported:"+now.isSupported(ChronoUnit.YEARS));
        System.out.println("isSupported:"+now.isSupported(ChronoUnit.MONTHS));
        System.out.println("isSupported:"+now.isSupported(ChronoUnit.DAYS));

        //get
        System.out.println("get:"+now.get(ChronoField.YEAR));
        //System.out.println("get:"+now.get(ChronoField.DAY_OF_YEAR));
        //System.out.println("get:"+now.get(ChronoField.DAY_OF_MONTH));
        //System.out.println("get:"+now.get(ChronoField.DAY_OF_WEEK));
        //System.out.println("get:"+now.get(ChronoField.NANO_OF_SECOND));
        //System.out.println("get:"+now.get(ChronoField.SECOND_OF_MINUTE));

        //isValidMonthDay
        MonthDay monthDay2 = MonthDay.of(2, 29);
        System.out.println("isValidMonthDay 2010:"+Year.of(2010).isValidMonthDay(monthDay2));
        System.out.println("isValidMonthDay 2011:"+Year.of(2011).isValidMonthDay(monthDay2));
        System.out.println("isValidMonthDay 2012:"+Year.of(2012).isValidMonthDay(monthDay2));
        System.out.println("isValidMonthDay 2013:"+Year.of(2013).isValidMonthDay(monthDay2));

        //parse
        System.out.println("parse:"+Year.parse("2010"));

        //plusYears
        System.out.println("plusYears:"+now.plusYears(10));

        //query
        System.out.println("query:"+now.query(TemporalQueries.chronology()));
        System.out.println("query:"+now.query(TemporalQueries.precision()));

        //range
        System.out.println("query:"+now.range(ChronoField.YEAR));

        //until
        LocalDate localDate1 = LocalDate.now().withYear(2050);
        System.out.println("until:"+now.until(localDate1, ChronoUnit.YEARS));

        //with
        LocalDate localDate2 = LocalDate.now().withYear(2050);
        System.out.println("with:"+localDate2);
    }
}

输出：

now:2021
2021-01-02
atDay:2021-04-15
atMonth:2021-05
atMonthDay:2010-07-16
compareTo:11
compareTo:-11
isAfter:true
isBefore:false
isLeap:false
isSupported:true
isSupported:false
isSupported:false
get:2021
isValidMonthDay 2010:false
isValidMonthDay 2011:false
isValidMonthDay 2012:true
isValidMonthDay 2013:false
parse:2010
plusYears:2031
query:ISO
query:Years
query:-999999999 - 999999999
until:29
with:2050-07-16