目录
- 内部源码详解
- 简单格式
- ISO-8601格式
- 格式说明
- 详解
- 源码介绍
- 总结
在新版本的spring boot中的Redis的时间相关的配置使用了 Java.time.Duration类
在配置时间时发现与老版本不同，就研究了下，发现使用了新的方式配置时间，这里记录下
从源码中可以看出 时间配置应该诸如： 1s 1.5s 0s 0.001S 1h 2d 1m 1M -PT0.001S P1DT2H15M(1天+2小时+15分钟) 形式
内部源码详解
1. 我们可通过源码找到springboot的转换器StringToDurationConverter,其中转换的核心代码使用了DurationStyle定义了时间格式:
private Duration convert(String source, DurationStyle style, ChronoUnit unit) {
style = (style != null) ? style : DurationStyle.detect(source);
return style.parse(source, unit);
}
2. 我们在DurationStyle中可以看到有两种格式(简单格式和ISO-8601格式)的支持:
/**
* Simple formatting, for example '1s'.(简单格式)
*/
SIMPLE("^([+-]?\\d+)([a-zA-Z]{0,2})$") {
......
},
/**
* ISO-8601 formatting. (ISO-8601格式)
*/
ISO8601("^[+-]?[pP].*$") {
......
};
简单格式
DurationStyle中简单格式支持的单位定义在下方的Unit枚举中:
- ns: 纳秒
- us: 微秒
- ms: 毫秒
- s: 秒
- m: 分钟
- h: 小时
- d: 天; (都不区分大小写)
/**
* Units that we support.
*/
enum Unit {
/**
* Nanoseconds.
*/
NANOS(ChronoUnit.NANOS, "ns", Duration::toNanos),
/**
* Microseconds.
*/
MICROS(ChronoUnit.MICROS, "us", (duration) -> duration.toNanos() / 1000L),
/**
* Milliseconds.
*/
MILLIS(ChronoUnit.MILLIS, "ms", Duration::toMillis),
/**
* Seconds.
*/
SECONDS(ChronoUnit.SECONDS, "s", Duration::getSeconds),
/**
* Minutes.
*/
MINUTES(ChronoUnit.MINUTES, "m", Duration::toMinutes),
/**
* Hours.
*/
HOURS(ChronoUnit.HOURS, "h", Duration::toHours),
/**
* Days.
*/
DAYS(ChronoUnit.DAYS, "d", Duration::toDays);
ISO-8601格式
格式说明
采用ISO-8601时间格式。格式为：PnYnMnDTnHnMnS （n为个数）
例如：P1Y2M3DT4H5M6.7S = 1年2个月3天4小时5分钟6.7秒
P：开始标记
- 1Y：1年 (Duration中没有)
- 2M：2个月 (Duration中没有)
- 3D：3天
T：日期和时间的分割标记
- 4H：4个小时
- 5M：5分钟
- 6.7S：6.7秒
注意: 这里的Duration只有D,H,M,S没有Y,M
详解
1."P", "D", "H", "M" 和 "S"可以是大写或者小写（建议大写）
2.可以用“-”表示负数
示例：
"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" python(where a day is 24 hours or 86400 seconds)
"P2DT3H4M" -- parses as "2 days, 3 hours and 4 minutes"
"PT-6H3M" --python parses as "-6 hours and +3 minutes"
"-PT6H3M" -- parses as "-6 hours and -3 minutes"
"-PT-6H+3M" -- parses as "+6 hours and -3 minutes"
源码介绍
ISO-8601格式在DurationStyle中直接是使用Duration.parse方法进行处理,Duration.parse方法的
定义如下:
/**
* 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编程客栈 from zero to 9 digits.
* <p&gwww.devze.comt;
* 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" 编程 -- 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) {
Objects.requireNonNull(text, "text");
Matcher matcher = PATTERN.matcher(text);
if (matcher.matches()) {
// check for letter T but no time sections
if ("T".equals(matcher.group(3)) == false) {
boolean negate = "-".equals(matcher.group(1));
String dayMatch = matcher.group(2);
String hourMatch = matcher.group(4);
String minuteMatch = matcher.group(5);
String secondMatch = matcher.group(6);
String fractionMatch = matcher.group(7);
if (dayMatch != null || hourMatch != null || minuteMatch != null || secondMatch != null) {
long daysAsSecs = parseNumber(text, dayMatch, SECONDS_PER_DAY, "days");
long hoursAsSecs = parseNumber(text, hourMatch, SECONDS_PER_HOUR, "hours");
long minsAsSecs = parseNumber(text, minuteMatch, SECONDS_PER_MINUTE, "minutes");
long seconds = parseNumber(text, secondMatch, 1, "seconds");
int nanos = parseFraction(text, fractionMatch, seconds < 0 ? -1 : 1);
try {
return create(negate, daysAsSecs, hoursAsSecs, minsAsSecs, seconds, nanos);
} catch (ArithmeticException ex) {
throw (DateTimeParseException) new DateTimeParseException("Text cannot be parsed to a Duration: overflow", text, 0).initCause(ex);
}
}
}
}
throw new DateTimeParseException("Text cannot be parsed to a Duration", text, 0);
}
总结
以上为个人经验，希望能给大家一个参考，也希望大家多多支持编程客栈(www.devze.com)。
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