简介
本文用示例介绍java的Duration的用法。
Duration和Period
说明
Duration类通过年月日时分秒相结合来描述一个时间量，最高精度是纳秒。时间量可以为正也可以为负，比如1天（86400秒0纳秒）、-1天（-86400秒0纳秒）、1年（31556952秒0纳秒）、1毫秒（0秒1000000纳秒）等。
Period类通过年月日相结合来描述一个时间量，最高精度是天。时间量可以为正也可以为负，例如2年（2年0个月0天）、3个月（0年3个月0天）、4天（0年0月4天）等。
这两个类是不可变的、线程安全的、最终类。都是JDK8新增的。
Period用法
见：Java–Period–使用/实例_IT利刃出鞘的博客-CSDN博客
创建方法
通过时间单位创建
基于天、时、分、秒、纳秒创建。
ofDays(), ofHours(), ofMillis(), ofMinutes(), ofNanos(), ofSeconds()。例如：
Duration fromDays = Duration.ofDays(1);
通过LocalDateTime或LocalTime
通过LocalDateTime或者LocalTime 类，然后使用between获取创建Duration。
LocalDateTime start = LocalDateTime.of(2022, 1, 1, 8, 0, 0); LocalDateTime end = LocalDateTime.of(2022, 1, 2, 8, 30, 30); Duration duration = Duration.between(start, end);
通过已有的Duration
Duration du1 = Duration.ofHours(10); Duration duration = Duration.from(du1);
解析方法
用法说明
用法示例
Duration fromChar1 = Duration.parse("P1DT1H10M10.5S");
Duration fromChar2 = Duration.parse("PT10M");
格式说明
采用ISO-8601时间格式。格式为：PnYnMnDTnHnMnS （n为个数）
例如：P1Y2M10DT2H30M15.03S
- P：开始标记
- 1Y：一年
- 2M：两个月
- 10D：十天
- T：日期和时间的分割标记
- 2H：两个小时
- 30M：三十分钟
- 15S：15.02秒
详解
- “P”, “D”, “H”, “M” 和 “S”可以是大写或者小写（建议大写）
- 可以用“-”表示负数
示例大全
"PT20.345S" -- parses as "20.345 seconds" "PT15M" -- parses as "15 minutes" (where a minute is 60 seconds) "PT10H" -- parses as "10 hours" (where an hour is 3600 seconds) "P2D" -- parses as "2 days" (where a day is 24 hours or 86400 seconds) "P2DT3H4M" -- parses as "2 days, 3 hours and 4 minutes" "P-6H3M" -- parses as "-6 hours and +3 minutes" "-P6H3M" -- parses as "-6 hours and -3 minutes" "-P-6H+3M" -- parses as "+6 hours and -3 minutes"
源码：
public final class Duration
implements TemporalAmount, Comparable<Duration>, Serializable {
//其他代码
//-----------------------------------------------------------------------
/**
* Obtains a {@code Duration} from a text string such as {@code PnDTnHnMn.nS}.
* <p>
* This will parse a textual representation of a duration, including the
* string produced by {@code toString()}. The formats accepted are based
* on the ISO-8601 duration format {@code PnDTnHnMn.nS} with days
* considered to be exactly 24 hours.
* <p>
* The string starts with an optional sign, denoted by the ASCII negative
* or positive symbol. If negative, the whole period is negated.
* The ASCII letter "P" is next in upper or lower case.
* There are then four sections, each consisting of a number and a suffix.
* The sections have suffixes in ASCII of "D", "H", "M" and "S" for
* days, hours, minutes and seconds, accepted in upper or lower case.
* The suffixes must occur in order. The ASCII letter "T" must occur before
* the first occurrence, if any, of an hour, minute or second section.
* At least one of the four sections must be present, and if "T" is present
* there must be at least one section after the "T".
* The number part of each section must consist of one or more ASCII digits.
* The number may be prefixed by the ASCII negative or positive symbol.
* The number of days, hours and minutes must parse to an {@code long}.
* The number of seconds must parse to an {@code long} with optional fraction.
* The decimal point may be either a dot or a comma.
* The fractional part may have from zero to 9 digits.
* <p>
* The leading plus/minus sign, and negative values for other units are
* not part of the ISO-8601 standard.
* <p>
* Examples:
* <pre>
* "PT20.345S" -- parses as "20.345 seconds"
* "PT15M" -- parses as "15 minutes" (where a minute is 60 seconds)
* "PT10H" -- parses as "10 hours" (where an hour is 3600 seconds)
* "P2D" -- parses as "2 days" (where a day is 24 hours or 86400 seconds)
* "P2DT3H4M" -- parses as "2 days, 3 hours and 4 minutes"
* "P-6H3M" -- parses as "-6 hours and +3 minutes"
* "-P6H3M" -- parses as "-6 hours and -3 minutes"
* "-P-6H+3M" -- parses as "+6 hours and -3 minutes"
* </pre>
*
* @param text the text to parse, not null
* @return the parsed duration, not null
* @throws DateTimeParseException if the text cannot be parsed to a duration
*/
public static Duration parse(CharSequence text) {
......
}
}
比较方法
比较两个时间的差
Instant start = Instant.parse("2017-10-03T10:15:30.00Z");
Instant end = Instant.parse("2017-10-03T10:16:30.00Z");
// start - end
Duration duration = Duration.between(start, end);
// 任何一个时间单元为负数，则返回true。true：end早于start
duration.isNegative();
Duration.between(start, end).getSeconds();
Duration.between(start, end).getNano();
增减方法
plusX()、minusX()
X表示days, hours, millis, minutes, nanos 或 seconds
Duration duration = Duration.ofHours(2); Duration newDuration = duration.plusSeconds(33);
plus()/minus()方法
带TemporalUnit 类型参数进行加减：
Duration duration = Duration.ofHours(2); Duration newDuration = duration.plus(33, ChronoUnit.SECONDS);
转换单位
可以用toX来转换为其他单位，支持：toDays, toHours, toMinutes, toMillis, toNanos
Duration duration = Duration.ofHours(2); duration.toDays(); // 0 duration.toHours(); // 2 duration.toMinutes(); // 120 duration.toMillis(); // 7200000 duration.toNanos(); // 7200000000000
取值方法
可以用getX来获得指定位置的值，因为Duration是由秒和纳秒组成，所以只能获得秒和纳秒：
Duration duration = Duration.ofHours(2); duration.getSeconds(); //7200 duration.getNano(); //0
请先 ！