带可选冒号分隔符的时区DateTimeFormatter？

Question

我正在尝试构建一个可以接受带冒号的偏移量或不带冒号的偏移量的DateTimeFormatter。

有没有办法通过这个测试：

DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss[X]");
dateTimeFormatter.parse("2015-01-28T10:21:44+0100"); // OK
dateTimeFormatter.parse("2015-01-28T10:21:44+01:00"); // KO

Answer 1

这一点：yyyy-MM-dd'T'HH:mm:ss[XXX][X]似乎是有效的。

DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss[XXX][X]");
dateTimeFormatter.parse("2015-01-28T10:21:44+0100");
dateTimeFormatter.parse("2015-01-28T10:21:44+01:00");

Answer 2

这里是最终的模式匹配，几乎所有看起来像ISO字符串日期的东西！

"[yyyyMMdd][yyyy-MM-dd][yyyy-DDD]['T'[HHmmss][HHmm][HH:mm:ss][HH:mm][.SSSSSSSSS][.SSSSSS][.SSS][.SS][.S]][OOOO][O][z][XXXXX][XXXX]['['VV']']"

它适用于下面的测试列表，除了注释中的两个，但我仍然不知道为什么……

    ZonedDateTime dt = DateTimeUtils.parse("2016-10-27T16:36:08.993+02:00:00[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993+02:00[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993+020000[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993+0200[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993+0000[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993Z[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993GMT+1[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993UTC[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993PST[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993[Europe/Paris]");

    dt = DateTimeUtils.parse("2016-10-27T16:36:08+02:00[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08+020000[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08+0200[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08+0000[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08Z[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08GMT+1[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08UTC[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08PST[Europe/Paris]");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08[Europe/Paris]");

    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993+02:00:00");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993+02:00");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993+020000");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993+0200");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993+0000");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993Z");
    //dt = DateTimeUtils.parse("2016-10-27T16:36:08.993GMT+1");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993UTC");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993PST");

    dt = DateTimeUtils.parse("2016-10-27T16:36:08.993");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.000993");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08.000000993");

    dt = DateTimeUtils.parse("2016-10-27T16:36:08+02:00:00");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08+02:00");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08+020000");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08+0200");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08+0000");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08Z");
    //dt = DateTimeUtils.parse("2016-10-27T16:36:08GMT+1");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08UTC");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08PST");
    dt = DateTimeUtils.parse("2016-10-27T16:36:08");

    dt = DateTimeUtils.parse("2016-100T16:36:08Z");
    dt = DateTimeUtils.parse("2016-100T16:36.1Z");
    dt = DateTimeUtils.parse("2016-10-27");

    dt = DateTimeUtils.parse("20161223T163608");
    dt = DateTimeUtils.parse("20161223T1636");

以及解析方法本身：

public static ZonedDateTime parse(CharSequence text) {
    TemporalAccessor temporalAccessor = LOOSE_ISO_DATE_TIME_ZONE_PARSER.parseBest(text, ZonedDateTime::from, LocalDateTime::from, LocalDate::from);
    if (temporalAccessor instanceof ZonedDateTime) {
        return ((ZonedDateTime) temporalAccessor);
    }
    if (temporalAccessor instanceof LocalDateTime) {
        return ((LocalDateTime) temporalAccessor).atZone(ZoneId.systemDefault());
    }
    return ((LocalDate) temporalAccessor).atStartOfDay(ZoneId.systemDefault());
}