[java][resttemplate] Fix model combining properties and additional properties

[JoaoBrlt]

When additionalProperties is set to true, use an additionalProperties attribute and @JsonAnySetter and @JsonAnyGetter annotations instead of extending HashMap.

This fixes the issue https://github.com/OpenAPITools/openapi-generator/issues/17361 only for the resttemplate library.

I also created the following pull requests to fix the same issue for other libraries:

• https://github.com/OpenAPITools/openapi-generator/pull/19711 for the webclient library.
• https://github.com/OpenAPITools/openapi-generator/pull/19713 for the feign library.

PR checklist

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• [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.
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• [x] File the PR against the correct branch: master (upcoming 7.x.0 minor release - breaking changes with fallbacks), 8.0.x (breaking changes without fallbacks)
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@bbdouglas (2017/07) @sreeshas (2017/08) @jfiala (2017/08) @lukoyanov (2017/09) @cbornet (2017/09) @jeff9finger (2018/01) @karismann (2019/03) @Zomzog (2019/04) @lwlee2608 (2019/10) @martin-mfg (2023/08) @wing328

[martin-mfg]

Hi @JoaoBrlt, thanks for the PRs! They look really good. 👍 I'll approve all 3 of them. May I ask you to resolve the conflicts with master?

[JoaoBrlt]

Hey @martin-mfg! :wave: Thanks for approving the pull requests. Yeah, no problem. I'll take a look right now.

[JoaoBrlt]

Hey @martin-mfg! I updated the pull requests to resolve the conflicts with the master branch. :heavy_check_mark: I redid the modifications using the latest Mustache templates to make sure to benefit from the latest changes. Don't hesitate to tell me if there's any issue.

[JoaoBrlt]

Hey @martin-mfg @wing328! :wave: Do you think we could merge these pull requests for the next version? This would be very useful for my current project. Indeed, we have to manually patch the OpenAPI specs to fix the code generation. I would be happy to help if needed. :smile:

[martin-mfg]

Hey @martin-mfg @wing328! 👋 Do you think we could merge these pull requests for the next version? This would be very useful for my current project. Indeed, we have to manually patch the OpenAPI specs to fix the code generation. I would be happy to help if needed. 😄

just for your info: I've done everything I could by approving your PR. :) Now it's up to @wing328 to merge it, because I don't have merge permissions.

[JoaoBrlt]

Hi @wing328 ! :wave: I just rebased the branch to avoid conflicts. Do you think we could merge this pull request? It should be a quick win and it would be very useful for my current project.

[wing328]

@JoaoBrlt thanks for the PR

please ping me via Slack for a quick chat when you've time: https://join.slack.com/t/openapi-generator/shared_invite/zt-2uoef5v0g-XGwo8~2oJ3EoziDSO1CmdQ

[jorgerod]

Hi @wing328 @JoaoBrlt @martin-mfg

I see that this PR has been approved and I don't quite know what state it is in or why it doesn't merge.

For me it would be very useful and I see that there are several issues related to this topic.

[mohsen-saeidi]

Are there any plans to merge this? this bug also blocks us

[wing328]

thanks for the PR, which has been merged.

sorry for the delay in merging as there're too many PRs pending review.

have a nice weekend.

[JoaoBrlt]

Hi @wing328 ! No problem, thank you for all the work that goes into maintaining the project! :muscle: Have a nice weekend.