On Sun, Sep 11, 2022 at 6:10 PM Terry M <tmosc...@gmail.com> wrote: > > Hi Tatu, > > Thank you for your work on Jackson. > > Could I propose date/time classes (in particular java.time.*) serialise as > RFC 3339 / ISO 8601 interchange format by default for Jackson 3, and not as > an epoch second, milli, micro or nano, etc. > > It is the recommended practice by many in the industry (E.g. Google / > Microsoft / json-schema validation, see links below) that RFC 3339 / ISO 8601 > be used for the serialisation format for date/times in JSON and in particular > JSON REST API design. > > It is also generally the default format used by java.time.* .toString() and > .parse() methods. > > RFC 3339 / ISO 8601, I would say, is a better format than an epoch as > > it is human readable > can preserve timezone information > has nano precision > has a maximum timestamp value that is not limited by the bit-length of a > double/long (platform specific) and > does not have unambiguous precision when inspecting the value (milli/micro, > etc). > > Additionally, is a more intuitive format for serialising LocalDate, rather > than the current default of a JSON numeric array of [year, month, day] > > Speaking from my experience, its seems a common source of bugs for developers > not realising that either overriding global config defaults (e.g. disable > SerializationFeature.WRITE_DATES_AS_TIMESTAMPS) or field level annotations > (@JsonFormat(shape = STRING)) are necessary (or possible) to serialise as > such. > > Other frameworks may for instance try to do this already, for example Spring > Boot's JacksonAutoConfiguration does this by default. > > I did see JSTEP-2: Changes to date/time defaults and JSTEP-5: Unify Date/Time > handling but it seems it hadn't come to a firm conclusion what the default > behaviour for date time serialisation in Jackson should be. > > Thanks for your consideration. > > References which consider RFC 3339 / ISO 8601 for datetime: > > Google JSON style guide - Date Time Property values > Microsoft API guidelines - JSON serialisation of dates and times > JSON Schema - dates and times > API Stylebook - date time - Collection of other vendor Styleguides
Thank you for this well-researched proposal. I think that it would make sense to change the defaults here. But how do others feel? Does anyone think that the use of (Java-centric) timestamps as the default would be better choice? -+ Tatu +- -- You received this message because you are subscribed to the Google Groups "jackson-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to jackson-dev+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/jackson-dev/CAL4a10iQ%2By__wLq3DX5mhX4kM1KX3ib4_p8CiXmUmqDcteuhHw%40mail.gmail.com.
