fix(java) #10010 oneOf and readOnly inheritance

[thorstenhirsch]

The java generator has problems with oneOf wrapper inheritance and inherited readOnly @JsonCreator as you can see in e.g. #10010. An example spec that results in broken generated code is e.g. https://app.swaggerhub.com/apis/cashlink-dev/issuer-api/v2

This PR fixes the issues, so that the java generator will generate compilable code and unit tests.

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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)

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Summary by cubic

Stops using oneOf wrapper schemas as parent classes and fixes @JsonCreator for inherited readOnly fields in the Java generator. Generates compilable models and updated samples. Fixes #10010.

• Bug Fixes
  • Detect oneOf wrapper schemas (oneOf + properties/discriminator) and inline their properties instead of treating them as parents.
  • Skip wrappers in parent resolution to avoid invalid inheritance.
  • Mark inherited readOnly vars and generate protected setters; update Java native pojo.mustache so @JsonCreator calls setters (handles JsonNullable too).
  • Add unit tests for both scenarios and update petstore Java native samples.

^{Written for commit 35e1a2f. Summary will update on new commits.}

[cubic-dev-ai]

1 issue found across 12 files

Prompt for AI agents (all issues)

Check if these issues are valid — if so, understand the root cause of each and fix them. If appropriate, use sub-agents to investigate and fix each issue separately.


<file name="modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache">

<violation number="1" location="modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache:98">
P2: Inherited readOnly properties with `x-is-jackson-optional-nullable` call the protected setter with a `JsonNullable<T>` value, but the setter expects `T`, causing a compile-time type mismatch in generated code.</violation>
</file>

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[cubic-dev-ai]

P2: Inherited readOnly properties with x-is-jackson-optional-nullable call the protected setter with a JsonNullable<T> value, but the setter expects T, causing a compile-time type mismatch in generated code.

Prompt for AI agents

Check if this issue is valid — if so, understand the root cause and fix it. At modules/openapi-generator/src/main/resources/Java/libraries/native/pojo.mustache, line 98:

<comment>Inherited readOnly properties with `x-is-jackson-optional-nullable` call the protected setter with a `JsonNullable<T>` value, but the setter expects `T`, causing a compile-time type mismatch in generated code.</comment>

<file context>
@@ -95,7 +95,7 @@ public class {{classname}} {{#parent}}extends {{{.}}} {{/parent}}{{#vendorExtens
   this();
   {{#readOnlyVars}}
-    this.{{name}} = {{#vendorExtensions.x-is-jackson-optional-nullable}}{{name}} == null ? JsonNullable.<{{{datatypeWithEnum}}}>undefined() : JsonNullable.of({{name}}){{/vendorExtensions.x-is-jackson-optional-nullable}}{{^vendorExtensions.x-is-jackson-optional-nullable}}{{name}}{{/vendorExtensions.x-is-jackson-optional-nullable}};
+    {{#vendorExtensions.x-is-inherited-readonly}}this.set{{nameInPascalCase}}({{#vendorExtensions.x-is-jackson-optional-nullable}}{{name}} == null ? JsonNullable.<{{{datatypeWithEnum}}}>undefined() : JsonNullable.of({{name}}){{/vendorExtensions.x-is-jackson-optional-nullable}}{{^vendorExtensions.x-is-jackson-optional-nullable}}{{name}}{{/vendorExtensions.x-is-jackson-optional-nullable}});{{/vendorExtensions.x-is-inherited-readonly}}{{^vendorExtensions.x-is-inherited-readonly}}this.{{name}} = {{#vendorExtensions.x-is-jackson-optional-nullable}}{{name}} == null ? JsonNullable.<{{{datatypeWithEnum}}}>undefined() : JsonNullable.of({{name}}){{/vendorExtensions.x-is-jackson-optional-nullable}}{{^vendorExtensions.x-is-jackson-optional-nullable}}{{name}}{{/vendorExtensions.x-is-jackson-optional-nullable}};{{/vendorExtensions.x-is-inherited-readonly}}
   {{/readOnlyVars}}
   }{{/withXml}}{{/vendorExtensions.x-has-readonly-properties}}
</file context>