import java.time.*;
import java.time.format.DateTimeFormatter;
import java.time.temporal.Temporal;
import java.time.temporal.TemporalAdjuster;
* @description: 验证JDK8的日期和时间类
* @author: xxx
* @date: 2021/12/02 22:08
public class TestLocalDateTime {
* 验证:LocalDate 日期 yyyy-MM-dd
@Test
public void testLocalDate(){
LocalDate.of(1985, 8, 6);
LocalDate.of(1985, Month.AUGUST,8);
LocalDate.ofYearDay(1985,218);
//从1970年之后的N天的日期
LocalDate.ofEpochDay(1);
LocalDate now = LocalDate.now();
now.getYear();
now.getMonth().getValue();
now.getDayOfMonth();
now.getDayOfWeek();
now.getDayOfYear();
* 验证:LocalTime 时间 HH:mm:ss(.ns)
@Test
public void testLocalTime(){
LocalTime.of(11, 15, 12, 234_444_933);
LocalTime.ofSecondOfDay(100L);
LocalTime.of(1, 1, 1);
LocalTime now = LocalTime.now();
now.getHour();
now.getMinute();
now.getSecond();
now.getNano();
* 验证:LocalDateTime 日期时间 yyyy-MM-ddTHH:mm:ss(.ns)
@Test
public void testLocalDateTime(){
LocalDateTime.of(1908, 12, 12, 12, 12, 12, 12);
LocalDateTime now = LocalDateTime.now();
now.getYear();
now.getMonthValue();
now.getDayOfMonth();
now.getDayOfYear();
now.getDayOfWeek();
now.getHour();
now.getMinute();
now.getSecond();
now.getNano();
* 验证:日期时间的操作
* 日期时间对象都是final修饰，不可变
@Test
public void testLocalDateTimeOption(){
//修改日期时间 不对原始对象做修改 withAttribute
LocalDateTime now = LocalDateTime.now();
LocalDateTime setYear = now.withYear(1993);
System.out.println(now);
System.out.println(setYear);
//在当前对象基础上加上or减去指定时间 plus | minus
now.plusDays(2);
now.plusMonths(2);
now.minusYears(1);
//日期比较 isBefore() isAfter() equal()
LocalDate of = LocalDate.of(1998, 12, 12);
System.out.println(LocalDate.now().isAfter(of));
//日期格式化,默认格式 yyyy-MM-ddTHH:mm:ss
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
System.out.println(now.format(formatter));
System.out.println(LocalDateTime.parse("1993-12-12 12:12:12", formatter));
System.out.println(LocalDateTime.parse("1993-12-12T12:12:12"));
* 日期时间差
* Duration: LocalTime之间的距离对象
* Period: LocalDate之间的距离对象
Duration duration = Duration.between(LocalTime.of(18, 12, 12), LocalTime.now());
System.out.println(duration.toDays());
System.out.println(duration.toHours());
System.out.println(duration.toMinutes());
//10天 = 240H
System.out.println(Duration.ofDays(10));
System.out.println(Duration.ofHours(1));
System.out.println(Duration.ofMinutes(6));
//10S
System.out.println(Duration.ofSeconds(10));
Period period = Period.between(LocalDate.now(), LocalDate.now().plusDays(1000));
System.out.println(period.getYears());
System.out.println(period.getMonths());
System.out.println(period.getDays());
* 验证:Instant类 -- 时间戳
@Test
public void testInstant(){
Instant now = Instant.now();
System.out.println(now);
//epoch 到现在的秒
System.out.println(now.getEpochSecond());
//纳秒数指的是该秒内的纳秒时间
System.out.println(now.getNano());
//epoch 到现在的 毫秒
System.out.println(now.toEpochMilli());
//等同于toEpochMilli
System.out.println(System.currentTimeMillis());
//epoch 之后的5秒
System.out.println(Instant.ofEpochSecond(5));
* 验证:时间校正器
@Test
public void testTimeTemporalAdjuster(){
LocalDateTime now = LocalDateTime.now();
//下个月的第一天
TemporalAdjuster temporalAdjuster = new TemporalAdjuster() {
@Override
public Temporal adjustInto(Temporal temporal) {
//这里temporal = now()
LocalDateTime now = (LocalDateTime)temporal;
System.out.println(now);
LocalDateTime nextMonth = now.plusMonths(1).withDayOfMonth(1);
return nextMonth;
System.out.println(now.with(temporalAdjuster));
* 验证:时区
* LocalDate/DateTime/Time 不带时区
* ZoneDate/DateTime/Time 带时区
@Test
public void testTimeZone(){
//获取所有的时区ID,格式为 区域/城市
//ZoneId.getAvailableZoneIds().forEach(System.out::println);
//根据当前系统的时区now(Clock.systemDefaultZone())，返回时间
System.out.println(LocalDateTime.now());
//获取带时区的类,世界标准时间
System.out.println(ZonedDateTime.now(Clock.systemUTC()));
System.out.println(ZonedDateTime.now());
//指定时区
System.out.println(ZonedDateTime.now(ZoneId.of("America/Vancouver")));
