目录
LocalDate/LocalTime/LocalDateTime类
ZoneDateTime和ZoneId
Instant类
DateTimeFormatter类 ：解析格式化时间
LocalDate/LocalTime/LocalDateTime类
package crrc.studytest1;import java.time.Duration;
import java.time.LocalDateTime;public class DurationClass {public static void main(String[] args) {//获取两个时间对象用来比较LocalDateTime start = LocalDateTime.of(1998,5,28,5,25,30);LocalDateTime end = LocalDateTime.of(2024,9,19,15,01,15);//创建一个Duration类来比较两个时间Duration duration = Duration.between(start,end);long days = duration.toDays();long hours = duration.toHours();long minutes = duration.toMinutes();long seconds = duration.getSeconds();long millis = duration.toMillis();long nanos = duration.toNanos();System.out.println(days);System.out.println(hours);System.out.println(minutes);System.out.println(seconds);System.out.println(millis);System.out.println(nanos);}
}
package crrc.studytest1;import java.time.LocalDate;
import java.time.LocalTime;public class LocalTimeClass {public static void main(String[] args) {//1.获取本地时间对象LocalTime ld = LocalTime.now();//时 分 秒 纳秒System.out.println(ld);//2.获取日期中的信息int hour = ld.getHour();//时int minute = ld.getMinute();//分int second = ld.getSecond();//秒int nano = ld.getNano();//纳秒System.out.println(hour);System.out.println(minute);System.out.println(second);System.out.println(nano);/*3.直接修改某个信息：withYear；withMonth.....都是以with开头，然后会返回一个新的对象，不会改变原有时间对象*/LocalTime ld2 = ld.withHour(15);System.out.println(ld2);LocalTime ld3 = ld2.withMinute(15);System.out.println(ld3);LocalTime ld33 = ld2.withSecond(0);System.out.println(ld33);//4.把某个信息加多少：plusYears；plusMonths；plusWeeks；LocalTime ld4 = ld.plusHours(10);System.out.println(ld4);LocalTime ld5 = ld.plusMinutes(10);System.out.println(ld5);//5.把某个信息减多少：minusYears；minusMonths；minusWeeks；minusDays；LocalTime ld6 = ld.minusHours(10);System.out.println(ld6);LocalTime ld7 = ld.minusSeconds(10);System.out.println(ld7);//6.获取指定日期的LocalDate对象：public static LocalDate of(int year,int month,int day)LocalTime ld8 = LocalTime.of(10,5,28);LocalTime ld9 = LocalTime.of(13,5,18);LocalTime ld10 = LocalTime.of(13,5,18);System.out.println(ld8);System.out.println(ld9);System.out.println(ld10);//7.判断两个日期对象，是否相等，在前还是在后： equals；isBefore；isAfter；System.out.println(ld9.equals(ld10));System.out.println(ld9.equals(ld8));System.out.println(ld8.isAfter(ld9));System.out.println(ld8.isBefore(ld9));}
}
package crrc.studytest1;import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;public class LocalDateTimeClass {public static void main(String[] args) {//用法基本和前面两个类一样 只不过把他们结合起来了 在这儿不演示了//简单用一下他们三者之间的转换LocalTime lt = LocalTime.now();LocalDate ld = LocalDate.now();LocalDateTime ldt = LocalDateTime.of(ld,lt);LocalDateTime ldt1 = LocalDateTime.now();LocalTime lt1 = ldt1.toLocalTime();LocalDate ld1 = ldt1.toLocalDate();System.out.println(lt);System.out.println(ld);System.out.println(ldt);System.out.println(ldt1);System.out.println(lt1);System.out.println(ld1);}
}
ZoneDateTime和ZoneId
package crrc.studytest1;import java.time.Clock;
import java.time.ZoneId;
import java.time.ZonedDateTime;public class ZoneId_ZoneDateTime {public static void main(String[] args) {//获取当前系统的时区id并打印出来// public static ZoneId systemDefault():获取系统默认时区ZoneId zoneId = ZoneId.systemDefault();System.out.println(zoneId);System.out.println(zoneId.getId());//获取Java支持的所有时区IDSystem.out.println(ZoneId.getAvailableZoneIds());//把某个时区ID封装成 ZoneId对象ZoneId zoneId1 = ZoneId.of("America/New_York");//ZoneDateTime 带时区的时间//public static ZoneDateTime now(ZoneId zone):获取某个时区的ZoneDateTime对象ZonedDateTime nowUSA = ZonedDateTime.now(zoneId1);ZonedDateTime nowChina = ZonedDateTime.now(zoneId);System.out.println(nowUSA);System.out.println(nowChina);//世界标准时间ZonedDateTime now = ZonedDateTime.now(Clock.systemUTC());System.out.println(now);//默认系统时间ZonedDateTime now2 = ZonedDateTime.now();System.out.println(now2);}
}
Instant类
package crrc.studytest1;import java.time.Instant;public class InstantClass {public static void main(String[] args) {//一般用来做代码性能分析 在代码执行前和代码执行后分别获取此刻时间戳，相减就是代码运行时间Instant instant = Instant.now();System.out.println(instant);//获取总秒数long second = instant.getEpochSecond();//获取不够1秒的纳秒数long nano = instant.getNano();System.out.println(second);System.out.println(nano);//也有plus minus 等方法 返回一个新的Instant对象}
}
DateTimeFormatter类 ：解析格式化时间
package crrc.studytest1;import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;public class DateTimeFormatterClass {public static void main(String[] args) {//用于时间格式化解析的//1.创建一个日期时间格式化对象器出来DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");//2.准备一些时间对其进行格式化LocalDateTime ldt = LocalDateTime.now();System.out.println(ldt);String strTime = dtf.format(ldt);//时间格式变成字符串(正向格式化)System.out.println(strTime);String strTime1 = ldt.format(dtf);//也可以用LocalDateTime类提供的format方法进行转换需要传入格式化器（反向格式化）System.out.println(strTime1);//3.解析时间 将字符串类型时间转换成相应时间对象String dateStr = "1998年5月28日 18:55:36";DateTimeFormatter dtf1 = DateTimeFormatter.ofPattern("yyyy年M月dd日 HH:mm:ss");LocalDateTime ldt1 = LocalDateTime.parse(dateStr,dtf1);System.out.println(ldt1);}
}
Period类
package crrc.studytest1;import java.time.LocalDate;
import java.time.Period;public class PeriodClass {public static void main(String[] args) {//1.先准备两个时间对象用于计算二者的时间间隔LocalDate ld1 = LocalDate.now();LocalDate ld2 = ld1.plusMonths(13);LocalDate ld3 = ld2.plusYears(5);LocalDate ld4 = ld3.plusDays(20);System.out.println(ld1);System.out.println(ld4);//2.创建一个Period对象Period p = Period.between(ld1,ld4);//3.获取两个日期相差的信息int year = p.getYears();int month = p.getMonths();int day = p.getDays();System.out.println(year);System.out.println(month);System.out.println(day);}
}
Duration类
package crrc.studytest1;import java.time.Duration;
import java.time.LocalDateTime;public class DurationClass {public static void main(String[] args) {//获取两个时间对象用来比较LocalDateTime start = LocalDateTime.of(1998,5,28,5,25,30);LocalDateTime end = LocalDateTime.of(2024,9,19,15,01,15);//创建一个Duration类来比较两个时间Duration duration = Duration.between(start,end);long days = duration.toDays();long hours = duration.toHours();long minutes = duration.toMinutes();long seconds = duration.getSeconds();long millis = duration.toMillis();long nanos = duration.toNanos();System.out.println(days);System.out.println(hours);System.out.println(minutes);System.out.println(seconds);System.out.println(millis);System.out.println(nanos);}
}
