How to Parse OffsetDateTime '2016-08-24T18:38:05.507+0000' in Java 8

Why can't OffsetDateTime parse '2016-08-24T18:38:05.507+0000' in Java 8?

OffsetDateTime.parse("2016-08-24T18:38:05.507+0000")

In Java 8, the OffsetDateTime class is designed to parse date-time strings that comply with the ISO-8601 standard. The string '2016-08-24T18:38:05.507+0000' does not conform to this format due to its timezone offset style, leading to a parsing exception when using the default parser.

String dateStr = '2016-08-24T18:38:05.507+0000';
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
OffsetDateTime dateTime = OffsetDateTime.parse(dateStr.replaceAll("([+-]\d{2})(\d{2})", "$1:$2"), formatter); 
System.out.println(dateTime);

Causes

• The date-time string is missing a colon in the timezone offset. The expected format would look like '+00:00' instead of '+0000'.
• The default parser of OffsetDateTime in Java 8 expects a specific format and fails if the string does not match it.

Solutions

• Change the format of the date-time string to include the colon in the timezone offset, resulting in '2016-08-24T18:38:05.507+00:00'.
• Use a custom DateTimeFormatter that can handle the original string format.
• Example code using a custom formatter:
• ```java
• import java.time.OffsetDateTime;
• import java.time.format.DateTimeFormatter;
• import java.time.format.DateTimeFormatterBuilder;
• import java.time.temporal.ChronoField;
• public class Main {
• public static void main(String[] args) {
• String dateStr = "2016-08-24T18:38:05.507+0000";
• DateTimeFormatter formatter = new DateTimeFormatterBuilder()
• .appendOptional(DateTimeFormatter.ISO_OFFSET_DATE_TIME)
• .parseDefaulting(ChronoField.OFFSET_SECONDS, 0)
• .toFormatter();
• OffsetDateTime dateTime = OffsetDateTime.parse(dateStr.replaceAll("([+-]\d{2})(\d{2})", "$1:$2"), formatter);
• System.out.println(dateTime);
• }
• }
• ```

Mistake: Assuming all date formats will automatically be parsed by OffsetDateTime.

Solution: Always ensure the input date format conforms to ISO-8601 or use a custom DateTimeFormatter.

Mistake: Ignoring the timezone offset format in date-time strings.

Solution: Always check for the expected timezone offset format (with colon) when parsing date-time strings.