LocalDateTime format with time zone and milliseconds

Question

I'm trying to write a DateTimeFormatter to parse the following format:

2020-05-29T07:51:33.106-07:00

I have looked at ISO_OFFSET_DATE_TIME, but the problem is it does not contain milliseconds. So I decided to write on my own.

It is easy to do so without timezone:

public static void main (String[] args) throws java.lang.Exception {
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSS");
    System.out.println(
        LocalDateTime.parse("2020-05-29T07:51:33.106", formatter)
    );
}

It works just fine

But when I tried to add a timezone in the format as

public static void main (String[] args) throws java.lang.Exception {
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
    System.out.println(
        LocalDateTime.parse("2020-05-29T07:51:33.106-07:00", formatter)
    );
}

It now fails with an exception that the timezone is unable to be parsed.

Exception in thread "main" java.time.format.DateTimeParseException: Text '2020-05-29T07:51:33.106-07:00' could not be parsed at index 23
    at java.base/java.time.format.DateTimeFormatter.parseResolved0(DateTimeFormatter.java:2049)
    at java.base/java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1951)
    at java.base/java.time.LocalDateTime.parse(LocalDateTime.java:492)
    at Ideone.main(Main.java:16)

How to parse a timezone in such a format?

Answer 1

From the Javadoc (emphasis mine):

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.

Change the single Z to ZZZZZ.