Java 8 日期时间格式化程序 : confusion with 'z' and 'Z ' pattern letters

Question

我有日期字符串“2015-01-12T13:00:00.000+02:00”。查看 JavaDoc，我看到以下内容:

z       time-zone name              zone-name         Pacific Standard Time; PST
Z       zone-offset                 offset-Z          +0000; -0800; -08:00;

所以我怀疑要解析它，我必须使用大写的“Z”，因为我有 +02:00 中给出的区域格式:

DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.000Z");

但是我得到了一个解析错误。

如果我使用小写字母“z”，它会起作用:

DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.000z")

有谁知道这是怎么回事吗？

---

代码:

DateTimeFormatter changetimeParser_Z = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.000Z");
DateTimeFormatter changetimeParser_z = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.000z");

String time = "2015-01-12T13:00:00.000+02:00";

ZonedDateTime time1 = ZonedDateTime.parse(time, changetimeParser_z);
System.out.println(time1);
ZonedDateTime time2 = ZonedDateTime.parse(time, changetimeParser_Z);

System.out.println(time2);

异常堆栈跟踪:

2015-01-12T13:00+02:00
java.time.format.DateTimeParseException: Text '2015-01-12T13:00:00.000+02:00' could not be parsed at index 23
    at java.time.format.DateTimeFormatter.parseResolved0(DateTimeFormatter.java:1949)
    at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1851)
    at java.time.ZonedDateTime.parse(ZonedDateTime.java:597)

Answer 1

我认为这是 Javadoc 中的一个错误，这部分是一个错误

Symbol  Meaning                     Presentation      Examples<br>
------  -------                     ------------      -------
Z       zone-offset                 offset-Z          +0000; -0800; -08:00;

因为如果你进一步阅读，你会发现偏移量 Z 的解释

Offset Z: This formats the offset based on the number of pattern letters. One, two or three letters outputs the hour and minute, without a colon, such as '+0130'. The output will be '+0000' when the offset is zero. Four letters outputs the full form of localized offset, equivalent to four letters of Offset-O. The output will be the corresponding localized offset text if the offset is zero. Five letters outputs the hour, minute, with optional second if non-zero, with colon. It outputs 'Z' if the offset is zero. Six or more letters throws IllegalArgumentException.

符合 RFC 822 .

对我来说，模式的行为应该与 SimpleDateFormat 相同