[BUG][Java][Spring] Always generate the default constructor if it is the only constructor

[anthonyvdotbe]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

The generator does not generate the default constructor if it is the only constructor. This is problematic, e.g., when such a class is in a package that is exported by a Java module and the module is compiled with javac -Xlint:all -Werror, because it fails the lint check missing-explicit-ctor.

openapi-generator version

v7.24.0

OpenAPI declaration file content or url

openapi.yaml

Generation Details

config.json

Steps to reproduce

• in a directory X, create openapi.yaml and config.json with the contents as above
• from within X, run docker run --rm -v .:/local openapitools/openapi-generator-cli:v7.24.0 generate --strict-spec true --input-spec /local/openapi.yaml --generator-name spring --config /local/config.json --output /local/output
• open .\output\src\main\java\org\openapitools\model\Foo.java

actual: the default constructor is not generated

expected: the default constructor is generated

Related issues/PRs

Suggest a fix

I assume this will require an update to the pojo.mustache template.

[jpfinne]

@anthonyvdotbe just a question: why do need linting on generated code?

you can use better linting tools and configure it to ignore files containing @Generated, no?

Have you tried the additionalModelTypeAnnotations @NoArgsConstructor lombok annotation?

[anthonyvdotbe]

@jpfinne because I expect code generators to generate decent code, because I don't want to complicate my build, and because the generated code might be part of the public interface, as in this case, and should meet the quality standards that go with that

Lombok is not an option for me.