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📜  Java8 Instant类

📅  最后修改于: 2020-10-01 06:42:16             🧑  作者: Mango

Java Instant类

Java Instant类用于表示时间轴上的特定时刻。它继承了Object类并实现Comparable接口。

Java Instant类声明

我们来看一下java.time.Instant类的声明。

public final class Instant extends Object 
implements Temporal, TemporalAdjuster, Comparable, Serializable

Java Instant的方法

Method Description
Temporal adjustInto(Temporal temporal). It is used to adjust the specified temporal object to have this instant.
int get(TemporalField field) It is used to get the value of the specified field from this instant as an int.
boolean isSupported(TemporalField field) It is used to check if the specified field is supported.
Instant minus(TemporalAmount amountToSubtract) It is used to return a copy of this instant with the specified amount subtracted.
static Instant now() It is used to obtain the current instant from the system clock.
static Instant parse(CharSequence text) It is used to obtain an instance of Instant from a text string such as 2007-12-03T10:15:30.00Z.
Instant plus(TemporalAmount amountToAdd) It is used to return a copy of this instant with the specified amount added.
Instant with(TemporalAdjuster adjuster) It is used to return an adjusted copy of this instant.

Java Instant示例：parse()

import java.time.Instant;
public class InstantExample1 {
  public static void main(String[] args) {
    Instant inst = Instant.parse("2017-02-03T10:37:30.00Z");
    System.out.println(inst);
  }
}

输出：

2017-02-03T10:37:30Z

Java Instant示例：now()

import java.time.Instant;
public class InstantExample2 {
  public static void main(String[] args) {
    Instant instant = Instant.now();
    System.out.println(instant);  
  }
}

输出：

2017-02-03T06:11:01.194Z

Java Instant示例：minus()

import java.time.*;
public class InstantExample3 {
  public static void main(String[] args) {
    Instant instant = Instant.parse("2017-02-03T11:25:30.00Z");
    instant = instant.minus(Duration.ofDays(125));
    System.out.println(instant); 
  }
}

输出：

2016-10-01T11:25:30Z

Java Instant示例：plus()

import java.time.*;
public class InstantExample4 {
  public static void main(String[] args) {
    Instant inst1 = Instant.parse("2017-02-03T11:25:30.00Z");
    Instant inst2 = inst1.plus(Duration.ofDays(125));
    System.out.println(inst2); 
  }
}

输出：

2017-06-08T11:25:30Z

Java Instant示例：isSupported()

import java.time.Instant;
import java.time.temporal.ChronoUnit;
public class InstantExample5 {
  public static void main(String[] args) {
    Instant inst = Instant.parse("2017-02-03T11:35:30.00Z");
    System.out.println(inst.isSupported(ChronoUnit.DAYS));
    System.out.println(inst.isSupported(ChronoUnit.YEARS));    
  }
}

输出：

true
false