有一个字符串代表日期(有或没有时间)喜欢13/12/2017
或13/12/2017 15:39:51
LocalDateTime localDateTime = LocalDateTime.parse("13/12/2017 15:39:51",DateTimeFormatter.ofPattern("dd/MM/yyyy[ HH:mm:ss]"));
System.out.println(localDateTime.format(DateTimeFormatter.ofPattern("dd/MM/yyyy")));
System.out.println(localDateTime.format(DateTimeFormatter.ofPattern("HH:mm:ss")));
13/12/2017
15:39:51
不明白为什么那个没有
LocalDateTime localDateTime = LocalDateTime.parse("13/12/2017",DateTimeFormatter.ofPattern("dd/MM/yyyy[ HH:mm:ss]"));
Exception in thread "main" java.time.format.DateTimeParseException: Text '13/12/2017' could not be parsed: Unable to obtain LocalDateTime from TemporalAccessor: {},ISO resolved to 2017-12-13 of type java.time.format.Parsed
at java.time.format.DateTimeFormatter.createError(DateTimeFormatter.java:1920)
at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1855)
at java.time.LocalDateTime.parse(LocalDateTime.java:492)
...
甚至还有
LocalDateTime localDateTime = LocalDateTime.parse("13/12/2017",DateTimeFormatter.ofPattern("dd/MM/yyyy"));
发布于 2018-08-29 10:39:40
使用可选组件时,应使用解析parseBest,
应用程序可能只在使用parse
,但它只是运气(因为你只解析完整的输入,而不是部分输入)。有了parseBest
,可以正确处理各种TemporalAccessor
,这是使用可选的全部原因。
TemporalAccessor
返回的决定相当简单:parseBest
将尝试TemporalQuery
按参数顺序匹配每个。当任何匹配时,该方法返回该匹配。因此,请确保从最精确到最精确。此外,如果没有匹配,则会抛出异常。
LocalDateTime dateTime;
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd/MM/yyyy[ HH:mm:ss]");
TemporalAccessor temporalAccessor = formatter.parseBest("13/12/2017", LocalDateTime::from, LocalDate::from);
if (temporalAccessor instanceof LocalDateTime) {
dateTime = (LocalDateTime)temporalAccessor;
} else {
dateTime = ((LocalDate)temporalAccessor).atStartOfDay();
}
https://stackoverflow.com/questions/-100006068
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