Fix: primitive boxed type schemas incorrectly cast to "string" in OAS 3.1 #4963

[K5qu4r3d]

Pull Request

Fixes: #4963

When generating OpenAPI 3.1 specs, @ApiResponse annotations that reference primitive boxed types (e.g. Boolean.class) as schema implementations produce a schema where the OAS 3.1 types set is correctly populated but type is then overwritten to "string". This causes invalid specs and incorrect client generation.

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What was broken

AnnotationsUtils falls back to setType("string") when a schema has no $ref and no type. It did not check getTypes(), so OAS 3.1 schemas that already had the correct types set were silently clobbered.

What changed

• AnnotationsUtils.java: added a doesSchemaHaveNullOrEmptyTypes guard to the setType("string") fallback so schemas already carrying an OAS 3.1 types value are not overwritten.

Type of Change

• 🐛 Bug fix
• ✨ New feature
• ♻️ Refactor (non-breaking change)
• 🧪 Tests
• 📝 Documentation
• 🧹 Chore (build or tooling)

Checklist

• I have added/updated tests as needed
• I have added/updated documentation where applicable
• The PR title is descriptive
• The code builds and passes tests locally
• I have linked related issues (if any)

Screenshots / Additional Context

• Added files:

  • modules/swagger-jaxrs2/src/test/java/io/swagger/v3/jaxrs2/resources/APIResponsesResource.java
  • modules/swagger-jaxrs2/src/test/java/io/swagger/v3/jaxrs2/APIResponsesResourceTest.java

• Affected files:

  • modules/swagger-core/src/main/java/io/swagger/v3/core/util/AnnotationsUtils.java
  • modules/swagger-core/src/main/java/io/swagger/v3/core/util/PrimitiveType.java
  • modules/swagger-java17-support/src/test/java/io/swagger/v3/java17/resolving/v31/ModelResolverOAS31Test.java
  • modules/swagger-core/src/test/java/io/swagger/v3/core/resolving/Ticket2992Test.java

[ewaostrowska]

There are still some failing tests in APIResponsesResourceTest.java. Please adjust tests :)

[ewaostrowska]

Hi @K5qu4r3d!
The fix in the AnnotationsUtils.java seems to be minimal and correct - the check on the types which is OAS 3.1 specific has been missing and adding it should restore setting the right types for this version of specification.
I have rolled back all the changes in PrimitiveType.class since :

• it would cause regression on fix: OAS 3.1 schema generation for raw Object properties #5034
• we do not want to set the type, which is OAS 3.0 specific, on schema for OAS 3.1. It is supposed to use types.