Equivalent of joda.ISODateTimeFormat in java.time?

Question

I have the following joda date parser:

ISODateTimeFormat.dateTimeParser().withOffsetParsed().

I'd like to refactor this to java.time api. But what is the exact equivalent to the parser above, especially regarding the offset?

Answer 1

The best equivalent should be this constant in package java.time.format which prefers the parsed offset according to the documentation (like the behaviour when Joda-withOffsetParsed() is used):

DateTimeFormatter.ISO_OFFSET_DATE_TIME

However, there are still small differences. The decimal separator must be a dot in Java-8 (comma not tolerated although valid and even recommended in ISO-paper). Also: Java-8 manages nanosecond precision in contrast to Jodas millisecond precision. And maybe most important difference: If the offset is missing in your input then Java-8 throws an exception but Joda not (and applies the default time zone).

About choice of type: Since you are working with DateTime and fixed offsets the best equivalent should be here OffsetDateTime in Java-8. Example of migration:

DateTime dt = ISODateTimeFormat.dateTimeParser().withOffsetParsed().parseDateTime(input);

=>

OffsetDateTime odt = OffsetDateTime.parse(input, DateTimeFormatter.ISO_OFFSET_DATE_TIME);