Java 持續時間

java中的Duration是一個用來測量以秒和奈秒為單位的時間的類別。 java中duration類別的套件是java.time.Duration。 Duration 類別物件指定時間段或用於確定兩個時間之間的差異。 Duration 物件是不可變的且是線程安全的，因為 Duration 物件是不可變的，因此一旦創建它，我們就無法更改它的值。但是，我們可以基於另一個 Duration 物件建立新的 Duration 物件。 Duration 類別繼承了一個物件類別（因為物件是 java 中所有類別的超類別）並實作了 Comparable 介面。

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文法

java中Duration類別宣告的語法是：

public final class Duration extends Object implements Comparable ,
TemporalAmount, Serializable
{
//
variables and method of the class Duration}

持續時間列表

Duration 類別方法清單在下面透過範例程式碼進行了解釋；範例程式碼可以進一步用於類似的方法（對於未給出的每個方法範例程式碼）：

• Duration abs()：此方法傳回此持續時間的副本，其長度為正。
• long get(TemporalUnit unit)：傳回請求單位的值。
• staticuration Between(Temporal startInclusive, Temporal endExclusive)：傳回duration對象，即兩個時間對象之間的持續時間。

範例#1

我們透過下面的範例java程式碼來理解上述方法。

代碼：

package p1;
import java.time.Duration;
import java.time.LocalTime;
import java.time.temporal.ChronoUnit;
public class DurationClassDemo {
public static void main(String[] args) {
Duration d = Duration.between(LocalTime.MAX,LocalTime.MIN);
System.out.println(d.get(ChronoUnit.SECONDS));
Duration absd = d.abs();
System.out.println(absd.get(ChronoUnit.SECONDS));
}
}

輸出：

• Temporal addTo(Temporaltemporal)：傳回duration對象，即temporal與thisduration物件相加。
• Duration splitBy(long divisor)：返回duration對象，即這個duration除以除數。

範例#2

我們透過下面的範例java程式碼來理解上述方法：

代碼：

package p1;
import java.time.Duration;
import java.time.*;
import java.time.temporal.ChronoUnit;
public class DurationClassDemo {
public static void main(String[] args) {
Duration d = Duration.between(LocalTime.MAX,LocalTime.MIN);
LocalDateTime date = LocalDateTime.now();
System.out.println(date);
date = (LocalDateTime)d.addTo(date);
System.out.println(date);
Duration d1 = d.dividedBy(4);
System.out.println(d1);
System.out.println(d.getSeconds());
System.out.println(d1.getSeconds());
}
}

輸出：

• intcompareTo(Duration otherDuration)：此時長與指定時長比較。
• boolean equals(Object otherDuration)：檢查指定 Duration 的持續時間並傳回布林值。
• boolean isNegative()：如果此持續時間為負數，則傳回 True。
• boolean isZero()：如果此持續時間長度為零，則傳回 True。

範例#3

我們透過下面的範例java程式碼來理解上述方法：

代碼：

package p1;
import java.time.Duration;
import java.time.*;
import java.time.temporal.ChronoUnit;
public class DurationClassDemo {
public static void main(String[] args) {
Duration d = Duration.between(LocalTime.NOON,LocalTime.MAX);
Duration d1 = Duration.between(LocalTime.NOON,LocalTime.MIN);
System.out.println(d1.getSeconds());
System.out.println(d.compareTo(d1));
System.out.println(d1.compareTo(d1));
System.out.println(d1.compareTo(d));
System.out.println(d1.equals(d));
System.out.println(d1.isNegative());
System.out.println(d1.isZero());
}
}

輸出：

• 靜態持續時間 from(TemporalAmount amount)：從時間量取得持續時間實例。

範例#4

我們透過下面的範例java程式碼來理解上述方法：

代碼：

package p1;
import java.time.Duration;
import java.time.*;
import java.time.temporal.ChronoUnit;
public class DurationClassDemo {
public static void main(String[] args) {
Duration d = Duration.from(ChronoUnit.DAYS.getDuration());
System.out.println(d.toMinutes());
}
}

輸出：

• int getNano()：傳回以奈秒為單位的持續時間。
• long getSeconds()：傳回以秒為單位的持續時間。
• 清單 getUnits(): 傳回此持續時間支援的單位集。
• int hashCode()：傳回此持續時間的雜湊程式碼。

範例#5

我們透過下面的範例java程式碼來理解上述方法：

代碼：

package p1;
import java.time.Duration;
import java.time.*;
import java.time.temporal.ChronoUnit;
public class DurationClassDemo {
public static void main(String[] args) {
Duration d = Duration.between(LocalTime.NOON,LocalTime.MAX);
System.out.println(d.getUnits());
System.out.println(d.toMinutes());
System.out.println(d.getSeconds());
System.out.println(d.getNano());
System.out.println(d.getClass());
}
}

輸出：

• Duration minus(Duration duration):- Returns object which results from this duration subtracted with the specified duration.
• Duration minus(long amountToSubtract, TemporalUnit unit): Returns object resulting from this duration subtracted with the specified duration.
• Duration minusDays(long daysToSubtract): Returns object which results from this duration subtracted with the specified duration in standard 24-hour days.
• Duration minusHours(long hoursToSubtract): Returns object resulting from this duration subtracted with the specified duration in hours.
• Duration minusMillis(long millisToSubtract): Returns object resulting from this duration subtracted with the specified duration in milliseconds.
• Duration minusMinutes(long minutesToSubtract): Returns object resulting from this duration subtracted with the specified duration in minutes.
• Duration minusNanos(long nanosToSubtract): Returns object resulting from this duration subtracted with the specified duration in nanoseconds.
• Duration minusSeconds(long secondsToSubtract): Returns object resulting from this duration subtracted with the specified duration in seconds.
• Duration multipliedBy(long multiplicand): Returns object resulting from this duration multiplied by the scalar.
• Duration negated() – Returns object which results from this duration with the length negated.
• static duration of(long amount, TemporalUnit unit): Returns Duration object representing an amount in the specified unit.
• static Duration ofDays(long days): Returns Duration object of standard 24-hour days.
• static Duration ofHours(long hours): Returns Duration object of the hour.
• static Duration ofMillis(long millis): Returns Duration object of milliseconds.
• static Duration ofMinutes(long minutes): Returns Duration object of minutes.
• static Duration ofNanos(long nanos): Returns Duration object of nanoseconds.
• static Duration ofSeconds(long seconds): Returns Duration object of seconds.
• static Duration ofSeconds(long seconds, long nanoAdjustment): Returns Duration object of seconds and nanoseconds adjustment.

Example #6

We understand the above methods with the below sample java code:

Code:

package p1;
import java.time.Duration;
import java.time.*;
import java.time.temporal.ChronoUnit;
public class DurationClassDemo {
public static void main(String[] args) {
Duration d = Duration.ofDays(6);
System.out.println(d.getSeconds());
Duration d1 = d.minusDays(3);
System.out.println(d1.getSeconds());
d = Duration.ofHours(6);
System.out.println(d.getSeconds());
d1 = d.minusHours(2);
System.out.println(d1.getSeconds());
}
}

Output:

• static Duration parse(CharSequence text): Return duration object from a text, for example, PnDTnHnMn.nS.
• Duration plus(Duration duration): Return the duration object of this duration with added the specified duration.
• Duration plus(long amountToAdd, TemporalUnit unit): Return the duration object of this duration with add the specified duration.
• Duration plusDays(long daysToAdd): Return the duration object of this duration with add the specified duration in 24-hour days.
• Duration plusHours(long hoursToAdd): Return the duration object of this duration with add the specified duration in hours.
• Duration plusMillis(long millisToAdd): Return the duration object of this duration with add the specified duration in milliseconds.
• Duration plusMinutes(long minutesToAdd): Return the duration object of this duration with the add specified duration in minutes.
• Duration plusNanos(long nanosToAdd): Return the duration object of this duration with add the specified duration in nanoseconds.
• Duration plusSeconds(long secondsToAdd): Return the duration object of this duration with the specified duration in seconds.

Example #7

We understand the above methods with the below sample java code:

Code:

package p1;
import java.time.Duration;
import java.time.*;
import java.time.temporal.ChronoUnit;
public class DurationClassDemo {
public static void main(String[] args) {
Duration d = Duration.ofDays(6);
System.out.println(d.getSeconds());
Duration d1 = d.plusDays(2);
System.out.println(d1.getSeconds());
d = Duration.ofHours(6);
System.out.println(d.getSeconds());
d1 = d.plusHours(2);
System.out.println(d1.getSeconds());
}
}

Output:

• Temporal subtractFrom(Temporal temporal): Return Subtraction of this duration from the temporal object.
• long toDays(): Return the number of days in this duration.
• long toHours(): Return the number of hours in this duration.
• long toMillis(): Return the number of milliseconds in this duration.
• long toMinutes(): return the number of minutes in this duration.
• long toNanos(): return the number of nanoseconds in this duration.
• String toString(): Return this duration in string representation, such as PT8H6M12.345S.

Example #8

We understand the above methods with the below sample java code:

Code:

package p1;
import java.time.Duration;
import java.time.*;
import java.time.temporal.ChronoUnit;
public class DurationClassDemo {
public static void main(String[] args) {
Duration d = Duration.ofDays(6);
System.out.println(d.toHours());
Duration d1 =Duration.ofHours(24) ;
System.out.println(d1.toDays());
}
}

Output:

• Duration withNanos(int nanoOfSecond): Returns duration object with the specified nanoofsecond.
• Duration withSeconds(long seconds): Returns duration object of this duration with the seconds of the specified amount.

Example #9

We understand the above methods with the below sample java code:

Code:

package p1;
import java.time.Duration;
import java.time.*;
import java.time.temporal.ChronoUnit;
public class DurationClassDemo {
public static void main(String[] args) {
Duration d = Duration.ofDays(6);
System.out.println(d.toString());
d = d.withSeconds(3000);
System.out.println(d.toString());
}
}

Output:

Conclusion

The Duration class is one of the built-in class in java, which is used to measure time in seconds and nanoseconds and add, subtract, and convert the duration, or, in simple words, the duration class allows performance operation on time or day duration. The duration class is available in java.time.Duration package of java.

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