java.time.Duration类是Java 8中添加的新日期和时间API的一部分，该API表示基于时间的时间量，例如" 34.5秒"。

持续时间类以秒和纳秒为单位对时间量或者时间量进行建模。可以使用其他基于持续时间的单位(例如分钟和小时)来访问它。此外，可以使用DAYS单位并将其视为完全等于24小时，因此忽略了夏时制的影响。

由于Duration类以秒和纳秒为单位对时间进行建模，因此它具有两个字段，其中一个字段长代表秒，一个int代表纳秒，始终在0到999,999,999之间。

Duration类中的of()方法

我们可以使用以下方法获取Duration类的实例：

• of(long amount, TemporalUnit unit)
• ofDays(long days)
• ofHours(long hours)
• ofMillis(long millis)
• ofMinutes(long minutes)
• ofNanos(long nanos)
• ofSeconds(long seconds)
• ofSeconds(long seconds, long nanoAdjustment)

public class DurationExample {
  public static void main(String[] args) {
    // Using days- stored as hours
    Duration duration = Duration.ofDays(122);
    System.out.println("Duration in days- " + duration);
    // Using hours- stored as hours
    duration = Duration.ofHours(150);	
    System.out.println("Duration in hours- " + duration);
    // Using minutes- stored as minutes
    duration = Duration.ofMinutes(220);	
    System.out.println("Duration in Minutes- " + duration);
    // Using Seconds
    duration = Duration.ofSeconds(12);
    System.out.println("Duration in Seconds- " + duration);
    // Using milliseconds- stored as Seconds
    duration = Duration.ofMillis(11);	
    System.out.println("Duration in Millis- " + duration);
    // Using nanoseconds- stored as Seconds
    duration = Duration.ofNanos(240000);
    System.out.println("Duration in Nanos- " + duration);
    // Using Seconds and nanoseconds
    duration = Duration.ofSeconds(1200, 245);
    System.out.println("Duration in Seconds and NanoSeconds- " + duration);
  }
}

输出：

Duration in days- PT2928H
Duration in hours- PT150H
Duration in Minutes- PT3H40M
Duration in Seconds- PT12S
Duration in Millis- PT0.011S
Duration in Nanos- PT0.00024S
Duration in Seconds and NanoSeconds- PT20M0.000000245S

使用ween()方法查找两个本地时间之间的差异

Java Duration类中有一个between方法

• 之间(时间开始包含在内，时间结束包含在内)

使用它可以获得两次之间的小时，分钟和秒数的持续时间。

public class DurationExample {
	public static void main(String[] args) {
		LocalTime t1 = LocalTime.of(5, 30, 56);
		LocalTime t2 = LocalTime.of(15, 35, 45);
		System.out.println("Start Time- " + t1);
		System.out.println("End Time- " + t2);
		Duration duration = Duration.between(t1, t2);
		// Total duration in hours
		System.out.println("Hours between- " + duration.toHours());
		// Total duration in Minutes
		System.out.println("Total difference in Minutes- " + duration.toMinutes());
		// Total duration in Seconds
		System.out.println("Total difference in Seconds- " + duration.toSeconds());
		
		// Difference between two times 
		System.out.println("Hours between " + duration.toHours());
		System.out.println("Minutes between " + duration.toMinutesPart());
		System.out.println("Seconds between " + duration.toSecondsPart());
	}
}

输出：

Start Time- 05:30:56
End Time- 15:35:45
Hours between 10
Minutes between 604
Seconds between 36289
Hours between 10
Minutes between 4
Seconds between 49

在这里，请注意toMinutes()和toMinutesPart()方法之间的区别，以及toSeconds()和toSecondsPart()方法之间的区别。

toMinutes()–获取此持续时间的分钟数。
toMinutesPart()–提取持续时间中分钟的分钟数。

toSeconds()–获取此持续时间的秒数。
toSecondsPart()–提取持续时间的秒数。

从给定时间开始的正负几天，小时，分钟，秒

使用plus(long amountToAdd，TemporalUnit单位)和minus(long amountToSubtract，TemporalUnit单位)方法可以从给定LocalTime中添加或者减去Duration。请注意，Duration类实现TemporalAmount。

public class DurationExample {
  public static void main(String[] args) {
    LocalTime lt = LocalTime.of(5, 30, 56);
    System.out.println("LocalTime- " + lt);
    System.out.println("Plus 2 hours " + lt.plus(Duration.ofHours(2))); 
    System.out.println("Plus 5 Minutes " + lt.plus(Duration.ofMinutes(5))); 
    System.out.println("Plus 20 Seconds " + lt.plus(Duration.ofSeconds(20))); 
  }
}

输出：

LocalTime- 05:30:56
Plus 2 hours 07:30:56
Plus 5 Minutes 05:35:56
Plus 20 Seconds 05:31:16

public class DurationExample {
	public static void main(String[] args) {
		LocalTime lt = LocalTime.of(5, 30, 56);
		System.out.println("LocalTime- " + lt);
		System.out.println("Minus 2 hours " + lt.minus(Duration.ofHours(2))); 
		System.out.println("Minus 45 Minutes " + lt.minus(Duration.ofMinutes(45))); 
		System.out.println("Minus 20 Seconds " + lt.minus(Duration.ofSeconds(20))); 
	}
}

输出：

LocalTime- 05:30:56
Minus 2 hours 03:30:56
Minus 45 Minutes 04:45:56
Minus 20 Seconds 05:30:36

将字符串转换为持续时间– parse()方法

• parse(CharSequence text)-从文本字符串(例如PnDTnHnMn.nS)获取持续时间。

在格式" PnDTnHnMn.nS"中，nD表示天数，T表示时间，nH表示小时数，nM表示分钟数，nS表示秒数。格式的字母接受大写或者小写。

public class DurationExample {
	public static void main(String[] args) {
		
		Duration duration = Duration.parse("PT20.345S");
		System.out.println("Duration- " + duration); 

		duration = Duration.parse("P2DT3H4M");
		System.out.println("Duration- " + duration); 
		
		duration = Duration.parse("PT-6H3M");
		System.out.println("Duration- " + duration); 
	}
}

输出：

Duration- PT20.345S
Duration- PT51H4M
Duration- PT-5H-57M