Add JsonFactoryBuilder.configureForJackson2(), JsonFactoryBuilder builderWithJackson2Defaults()

[pjfanning]

• Relates to Add JsonMapper builder support in Jackson 3.0 for optionally creating mappers with Jackson2 config defaults jackson-databind#4986

[cowtowncoder]

Makes sense as a starting point, but if the idea is to add same functionality for other backends, should probably implement in a way that can share general (non-JSON-specific) settings.
So parts in TokenStreamFactory/TSFBuilder, parts in JsonFactory/JsonFactoryBuilder.

And in fact, instead of (or in addition to?) having all of these in Builder factory method, could perhaps have builder member method like TSFBuilder.configureForJackson2().
This could be called separately, as well as part of factory method?

[pjfanning]

Makes sense as a starting point, but if the idea is to add same functionality for other backends, should probably implement in a way that can share general (non-JSON-specific) settings. So parts in TokenStreamFactory/TSFBuilder, parts in JsonFactory/JsonFactoryBuilder.

And in fact, instead of (or in addition to?) having all of these in Builder factory method, could perhaps have builder member method like TSFBuilder.configureForJackson2(). This could be called separately, as well as part of factory method?

I thought about having it on the builder but my worry is that users will then use annoying ordering in chaining their commands to configure the builder. Someone is bound to come along and create a build, set some config then call configureForJackson2() and that could undo some of their pre-set config. I guess you could say that about any command chaining on the builder but the actions of configureForJackson2() are a bit opaque - you need to read the code to see hat it does.

[cowtowncoder]

@pjfanning I still suggest adding configure method in Builder instance even if called from static factory method that creates Builders. That allows composition of TSFBuilder (format-agnostic settings) and format-specific actually builder (like JsonFactoryBuilder).

Configure method can then be alternatively called by someone being only handed Builder, as opposed to only being available from Factory.

[pjfanning]

configureForJackson2

I added configureForJackson2 in latest commit.