[Java/Spring] Revert to fully qualified import for org.springframework.core.io.Resource

[cachescrubber]

Last Minute correction:

Revert to fully qualified import for org.springframework.core.io.Resource

On final Decision:

Springdoc (OAS3) is the default Documentation Provider since (#11258)

Should we set it to Springfox (OAS2) for 5.4.0, switching the default in 6.0?

PR checklist

• [x ] Read the contribution guidelines.
• [ x] Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
• [ x] Run the following to build the project and update samples:

  ./mvnw clean package 
  ./bin/generate-samples.sh
  ./bin/utils/export_docs_generators.sh
  

  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
  You may regenerate an individual generator by passing the relevant config(s) as an argument to the script, for example ./bin/generate-samples.sh bin/configs/java*.
  For Windows users, please run the script in Git BASH.
• File the PR against the correct branch: master (5.3.0), 6.0.x
• If your PR is targeting a particular programming language, @mention the technical committee members, so they are more likely to review the pull request.

[cachescrubber]

@wing328 FYI

[cachescrubber]

@welshm What do you think should be the default in 5.4.0?

[welshm]

@welshm What do you think should be the default in 5.4.0?

IMO I would default to OAS2 / SpringFox for backwards compatibility and change the default in 6.0.

Easy enough for people who want it to set the correct configurations and doesn't break people who just want stability improvements from the generator update

[wing328]

Springdoc (OAS3) is the default Documentation Provider since (#11258)

5.4.0 allows breaking changes with fallback so it's ok to do so

[cachescrubber]

Ok, then we go for Springdoc (OAS3).