Java8 新特性 - 新时间与日期API

package com.xq.java8;

import org.junit.jupiter.api.Test;

import java.time.*;
import java.time.format.DateTimeFormatter;
import java.time.temporal.TemporalAdjusters;
import java.util.Set;

public class TestLocalDateTime {

    // ZonedDate、ZonedTime、ZonedDateTime
    @Test
    public void test7(){
        Set<String> set = ZoneId.getAvailableZoneIds();
        set.forEach(System.out::println);
    }
    @Test
    public void test8(){
        LocalDateTime ldt = LocalDateTime.now(ZoneId.of("America/Rosario"));
        System.out.println(ldt);
        LocalDateTime ldt2 = LocalDateTime.now(ZoneId.of("America/Rosario"));
        ZonedDateTime zdt = ldt2.atZone(ZoneId.of("America/Rosario"));
        System.out.println(zdt);
    }

    //DateTimeFormatter : 格式化时间 / 日期
    @Test
    public void test6(){
        DateTimeFormatter dt = DateTimeFormatter.ISO_DATE;
        LocalDateTime ldt = LocalDateTime.now();
        String str = ldt.format(dt);
        System.out.println(str);
        System.out.println("--------------------");

        DateTimeFormatter dtf2 = DateTimeFormatter.ofPattern("yyyy年MM月dd日 HH:mm:ss");
        String strDate2 = dtf2.format(ldt);
        System.out.println(strDate2);

        LocalDateTime newdate = ldt.parse(strDate2,dtf2);
        System.out.println(newdate);
    }

    // TemporalAdjuster：时间校正器
    @Test
    public void test5(){
        LocalDateTime ldt = LocalDateTime.now();
        System.out.println(ldt);

        LocalDateTime ldt2 = ldt.withDayOfMonth(10);
        System.out.println(ldt2);

        LocalDateTime ldt3 = ldt.with(TemporalAdjusters.next(DayOfWeek.SUNDAY));
        System.out.println(ldt3);

        // 自定义：下一个工作日
        LocalDateTime ldt5 = ldt.with((l) -> {
            LocalDateTime ldt4 = (LocalDateTime)l;
            DayOfWeek dow = ldt4.getDayOfWeek();
            if(dow.equals(DayOfWeek.FRIDAY)){
                return ldt4.plusDays(3);
            } else if(dow.equals(DayOfWeek.SATURDAY)){
                return ldt4.plusDays(2);
            } else {
                return ldt4.plusDays(1);
            }
        });
        System.out.println(ldt5);
    }
    // 1.LocalDate LocalTime  LocalDateTime
    // 2. Instant: 时间戳（以 Unix 元年：1970年1月1日 00:00:00 到某个时间的毫秒值）
    @Test
    public  void test2(){
        Instant ins1 = Instant.now();
        System.out.println(ins1);
        OffsetDateTime odt = ins1.atOffset(ZoneOffset.ofHours(8));
        System.out.println(odt);
        System.out.println(ins1.toEpochMilli());
    }
    @Test
    public void test1(){
        LocalDateTime ldt = LocalDateTime.now();
        System.out.println(ldt);

        LocalDateTime ldt2 = LocalDateTime.of(2020,5,13,13,11,33);
        System.out.println(ldt2);

        LocalDateTime ldt3 = ldt.plusYears(2);
        System.out.println(ldt3);

        LocalDateTime ldt4 = ldt.minusMonths(2);
        System.out.println(ldt4);

        System.out.println(ldt.getYear());
        System.out.println(ldt.getMonthValue());
        System.out.println(ldt.getDayOfMonth());
        System.out.println(ldt.getHour());
        System.out.println(ldt.getMinute());
    }
}