Support Jackson 3

[ihostage]

Jackson Release 3.0
What do you think about support a new major version of Jackson in Pekko 2.0.0?

[pjfanning]

I'm a Jackson contributor and Pekko contributor. This is my opinion (as opposed to a Jackson team or Pekko team opinion) - Jackson 3 is a big change. There are also some issues in the initial release.
Users who are are happy with Jackson 2 should stick with Jackson 2 for the next while. Bugs will be fixed in Jackson 2. There are no super new features in Jackson 3. It is basically a tidy up of the APIs and default configuration.
Users may find that they rely on some of the config settings whose defaults have changed in Jackson 3.

I have personally released Jackson 3 support for Pekko but I don't expect many people to use it.

• https://github.com/pjfanning/pekko-serialization-jackson3
• https://github.com/pjfanning/pekko-http-json (includes "com.github.pjfanning" %% "pekko-http-jackson" and "com.github.pjfanning" %% "pekko-http-jackson3" for Jackson 2 and 3 support respectively)

[mkurz]

@pjfanning Do you have any information on how long Jackson 2.x will be maintained? I guess it will take a long time (years?) until libraries and projects migrate to Jackson 3 (even more because the groupid and the namespace changed - plus the Java 17 requirement).
So my question is, will there be more 2.x minor releases (2.21, 2.22,...) or do the Jackson maintainers expect everyone to upgrade to Jackson 3 and will stop 2.x development soon?
For me, looking at https://github.com/FasterXML/jackson/wiki/Jackson-Releases, it seems that Jackson 3 and 2 will coexist at least for a while (?) as it states that 2.21 started development in September. Is the purpose of 2.21 to just simplify the upgrade experience to 3 (in a way like new Scala 2.13 releasees often catch up with latest Scala 3 stable to ease migration) - or is the intention to just continue Jackson 2 development independent of version 3?

[pjfanning]

@mkurz I don't see any push to abandon 2.x. It will probably be left without too much going on other than bug fixes but I think they will happen for at least a year or 2 and probably longer than that. 2.x will be stable while 3.x could see a bit of churn while teething issues are sorted out.