Java8新特性 - LocalTime 时间类的基本使用
1.说明
LocalTime 是 Java8 中新增的 时间类，主要包含了 小时、分钟、秒、纳秒 四个属性。
LocalTime类中提供了丰富的API，帮助我们更加简便的操作时间对象。
2.常用API
2.1 创建LocalTime类对象
* 1.创建时间类对象
* 1.1 获取当前时间
* LocalTime.now() : 获取默认时区下的系统时钟的时间
* LocalTime.now(Clock clock) : 获取指定时钟的时间
* LocalTime.now(ZoneId zone) : 获取指定时区的、默认系统时钟的时间
* 【补充：获取所有时区信息的方式 ： ZoneId.getAvailableZoneIds()】
* 1.2 获取指定时间
* * 小时的取值范围 : [0,23]
* * 分钟的取值范围 : [0,59]
* * 秒 的取值范围 : [0,59]
* * 纳秒的取值范围 : [0,999,999,999]
*
* LocalTime.of(int hour, int minute) : 指定小时和分钟，秒和纳秒为0
* LocalTime.of(int hour, int minute, int second) : 指定小时、分钟、秒，纳秒为0
* LocalTime.of(int hour, int minute, int second, int nanoOfSecond) : 指定小时、分钟、秒、纳秒
* LocalTime.ofSecondOfDay(long secondOfDay) : 指定一天当中的多少秒，纳秒将被置为0
* LocalTime.ofNanoOfDay(long nanoOfDay) : 指定一天当中的多少纳秒
*
代码
package com.northcastle.K_Date;
import java.time.Clock;
import java.time.Duration;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAdjuster;
public class LocalTimeTest {
public static void main(String[] args) {
//1.1 获取当前时间
LocalTime now01 = LocalTime.now(); // 我们是中国北京，东八区
System.out.println("now01 = " + now01);
LocalTime now02 = LocalTime.now(Clock.systemUTC()); // UTC/GMT 标准时区时间,零时区/中时区
System.out.println("now02 = " + now02);
LocalTime now03 = LocalTime.now(ZoneId.of("America/Panama")); // Asia/Shanghai 东八区 ；America/Panama 西五区
System.out.println("now03 = " + now03);
System.out.println("===========================");
//1.2 获取指定时间
LocalTime localTime01 = LocalTime.of(18, 10);
System.out.println("localTime01 = " + localTime01);
LocalTime localTime02 = LocalTime.of(19, 44, 56);
System.out.println("localTime02 = " + localTime02);
LocalTime localTime03 = LocalTime.of(19, 45, 12, 126);
System.out.println("localTime03 = " + localTime03);
LocalTime localTime04 = LocalTime.ofSecondOfDay(56);
System.out.println("localTime04 = " + localTime04);
LocalTime localTime05 = LocalTime.ofNanoOfDay(100);
System.out.println("localTime05 = " + localTime05);
System.out.println("===========================");
//获取所有可用的时区
// List zoneIds = ZoneId.getAvailableZoneIds().stream()
// .filter(s -> s.startsWith("Ame"))
// .collect(Collectors.toList());
// System.out.println(zoneIds);
}
}
运行结果
2.2 获取LocalTime对象的时分秒
* 2.获取时间对象的 时、分、秒、纳秒、信息
* getHour() : 获取小时信息
* getMinute() : 获取分钟信息
* getSecond() : 获取秒
* getNano() : 获取纳秒
*
代码
package com.northcastle.K_Date;
import java.time.Clock;
import java.time.Duration;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAdjuster;
public class LocalTimeTest {
public static void main(String[] args) {
//2.获取时间对象的 时、分、秒、纳秒
LocalTime now = LocalTime.now();
System.out.println("now = " + now);
System.out.println("小时 ： " + now.getHour());
System.out.println("分钟 ： " + now.getMinute());
System.out.println("秒 ： " + now.getSecond());
System.out.println("纳秒 ： " + now.getNano());
System.out.println("===========================");
}
}
运行结果
2.3 指定LocalTime对象的时分秒信息
* 3.指定时间对象的 时、分、秒、纳秒
* withHour(int) : 指定小时
* withMinute(int) : 指定分钟
* withSecond(int) : 指定秒
* withNano(int) : 指定毫秒
*
* with(TemporalAdjuster) : 时间矫正器
*
代码
package com.northcastle.K_Date;
import java.time.Clock;
import java.time.Duration;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAdjuster;
public class LocalTimeTest {
public static void main(String[] args) {
//3.指定时、分、秒、纳秒
LocalTime nowWith = LocalTime.now();
System.out.println("nowWith = " + nowWith);
System.out.println("指定小时6点 = " + nowWith.withHour(6));
System.out.println("指定分钟5分钟 = " + nowWith.withMinute(50));
System.out.println("指定秒5秒 = " + nowWith.withSecond(5));
System.out.println("指定纳秒123000000 = " + nowWith.withNano(123000000));
System.out.println();
//时间矫正器
TemporalAdjuster temporalAdjuster = (temporal)->{
System.out.println("temporal = " + temporal);
LocalTime localTime = (LocalTime) temporal;
localTime = localTime.withHour(localTime.getHour()+1)
.withMinute(30)
.withSecond(30)
.withNano(300000000);
System.out.println("localTime = " + localTime);
return localTime;
};
LocalTime withTemporalAdjuster01 = nowWith.with(temporalAdjuster);
System.out.println("withTemporalAdjuster01 = " + withTemporalAdjuster01);
System.out.println("===========================");
}
}
运行结果
2.4 增加/减少 LocalTime 对象的时分秒信息
* 4.加上 或者 减去 时、分、秒、纳秒
* plusHours(long) : 加几个小时
* plusMinutes(long) : 加几分钟
* plusSeconds(long) : 加几秒钟
* plusNanos(long) : 加几个纳秒
*
* minusHours(long) : 减几个小时
* minusMinutes(long) : 减几分钟
* minusSeconds(long) : 减几秒
* minusNanos(long) : 减几个纳秒
*
代码
package com.northcastle.K_Date;
import java.time.Clock;
import java.time.Duration;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAdjuster;
public class LocalTimeTest {
public static void main(String[] args) {
//4.加上 或者 减去 小时、分钟、秒、纳秒
LocalTime nowPlusOrMin = LocalTime.now();
System.out.println("nowPlusOrMin = " + nowPlusOrMin);
System.out.println("加两小时 = " + nowPlusOrMin.plusHours(2));
System.out.println("加20分钟 = " + nowPlusOrMin.plusMinutes(20));
System.out.println("加20秒 = " + nowPlusOrMin.plusSeconds(20));
System.out.println("加1纳秒 = " + nowPlusOrMin.plusNanos(1));
System.out.println();
System.out.println("减两小时 = " + nowPlusOrMin.minusHours(2));
System.out.println("减20分钟 = " + nowPlusOrMin.minusMinutes(20));
System.out.println("减20秒 = " + nowPlusOrMin.minusSeconds(20));
System.out.println("减1纳秒 = " + nowPlusOrMin.minusNanos(1));
System.out.println("===========================");
}
}
运行结果
2.5 LocalTime 对象的大小比较
* 5.比较时间对象的大小
* time01.isAfter(time02) : time01 是否比 time02 晚
* time01.isBefore(time02) : time01 是否比 time02 早
*
代码
package com.northcastle.K_Date;
import java.time.Clock;
import java.time.Duration;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAdjuster;
public class LocalTimeTest {
public static void main(String[] args) {
//5.比较两个时间对象的大小
LocalTime time01 = LocalTime.now();
LocalTime time02 = LocalTime.of(21, 28, 30);
System.out.println("time01 = " + time01);
System.out.println("time02 = " + time02);
System.out.println("time01是否比time02 晚 ： " + time01.isAfter(time02));
System.out.println("time01是否比time02 早 ： " + time01.isBefore(time02));
System.out.println("===========================");
}
}
运行结果
2.6 LocalTiime 对象格式化为字符串
* 6.时间对象 与 字符串的相互转化
* 6.1 时间对象 转 字符串 format() + DateTimeFormatter类
* String format01 = localTime.format(DateTimeFormatter.ISO_TIME); // 21:56:17.05
* String format02 = localTime.format(DateTimeFormatter.ISO_LOCAL_TIME); // 21:56:17.05
* String format03 = localTime.format(DateTimeFormatter.ofPattern("HH--:--mm--:--ss")); // 21--:--56--:--17
*
* 6.2 字符串 转 时间对象 parse()
* LocalTime timeParse01 = LocalTime.parse("21:53:53", DateTimeFormatter.ofPattern("HH:mm:ss"));
*
代码
package com.northcastle.K_Date;
import java.time.Clock;
import java.time.Duration;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAdjuster;
public class LocalTimeTest {
public static void main(String[] args) {
//6.1 时间对象 转 字符串
LocalTime timeFormat01 = LocalTime.now();
System.out.println("timeFormat01 = " + timeFormat01);
String format01 = timeFormat01.format(DateTimeFormatter.ISO_TIME); // 21:56:17.05
System.out.println("format01(ISO_TIME) = " + format01);
String format02 = timeFormat01.format(DateTimeFormatter.ISO_LOCAL_TIME); // 21:56:17.05
System.out.println("format02(ISO_LOCAL_TIME) = " + format02);
String format03 = timeFormat01.format(DateTimeFormatter.ofPattern("HH--:--mm--:--ss")); // 21--:--56--:--17
System.out.println("format03 = " + format03);
System.out.println();
//6.2 字符串 转 时间对象
LocalTime timeParse01 = LocalTime.parse("21:53:53", DateTimeFormatter.ofPattern("HH:mm:ss"));
System.out.println("timeParse01 = " + timeParse01);
System.out.println("===========================");
}
}
运行结果
2.7 计算两个时间对象之间的时间差
* 7.获取两个时间对象之间的差 Duration
* Duration between = Duration.between(timeDuration01, timeDuration02);
* between.toDays()
* between.toHours() // 一共差多少个小时
* between.toMinutes() // 一共差多少个分钟
* between.toMillis() // 一共差多少毫秒
* between.toNanos() // 一共差多少纳秒
*
代码
package com.northcastle.K_Date;
import java.time.Clock;
import java.time.Duration;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.time.temporal.TemporalAdjuster;
public class LocalTimeTest {
public static void main(String[] args) {
//7.获取两个时间对象之间的差
LocalTime timeDuration01 = LocalTime.of(22, 38, 50);
System.out.println("timeDuration01 = " + timeDuration01);
LocalTime timeDuration02 = LocalTime.of(22, 56, 32);
System.out.println("timeDuration02 = " + timeDuration02);
Duration between = Duration.between(timeDuration01, timeDuration02);
System.out.println("between.toDays() = " + between.toDays());
System.out.println("between.toHours() = " + between.toHours()); // 一共差多少个小时
System.out.println("between.toMinutes() = " + between.toMinutes()); // 一共差多少个分钟
System.out.println("between.toMillis() = " + between.toMillis()); // 一共差多少毫秒
System.out.println("between.toNanos() = " + between.toNanos()); // 一共差多少纳秒
System.out.println();
System.out.println("ChronoUnit.HOURS.between(timeDuration01,timeDuration02) = " + ChronoUnit.HOURS.between(timeDuration01, timeDuration02));
System.out.println("ChronoUnit.MINUTES.between(timeDuration01,timeDuration02) = " + ChronoUnit.MINUTES.between(timeDuration01, timeDuration02));
System.out.println("ChronoUnit.MILLIS.between(timeDuration01,timeDuration02) = " + ChronoUnit.MILLIS.between(timeDuration01, timeDuration02));
System.out.println("ChronoUnit.NANOS.between(timeDuration01,timeDuration02) = " + ChronoUnit.NANOS.between(timeDuration01, timeDuration02));
System.out.println("===========================");
}
}
运行结果
3.完成
Congratulations!
You are one step closer to success!