How to Parse ISO 8601 Strings Without Colon in Offset in Java 8 Date and Time?

How can I parse an ISO 8601 date-time string that lacks a colon in its offset using Java 8?

String dateTimeString = "2022-03-21T10:15:30-0500";

Java 8 introduced a robust Date and Time API that allows for easy manipulation and parsing of date-time strings. However, when dealing with ISO 8601 formatted strings that lack a colon in the offset (e.g., `-0500` instead of `-05:00`), we need to implement a custom parsing approach.

String dateTimeString = "2022-03-21T10:15:30-0500";
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ssZ");
OffsetDateTime dateTime = OffsetDateTime.parse(dateTimeString, formatter);

Causes

• ISO 8601 represents date and time in a standard format.
• The absence of a colon in the offset can lead to parsing errors using standard methods.

Solutions

• Use `DateTimeFormatter` with a custom pattern to parse these strings.
• Consider replacing the offset format before parsing for compatibility.
• Utilize `OffsetDateTime` and configure it to accommodate string formats.

Mistake: Using standard ISO 8601 parsers without customizing for offset.

Solution: Always check if the date-time strings conform to your expected format.

Mistake: Ignoring potential exceptions during parsing.

Solution: Implement try-catch blocks to handle parsing exceptions gracefully.