[BUG][SPRING] Webflux minItems generates incompatible validation annotation

Description

Webflux minItems generates incompatible validation annotation. Size cannot validate a flux.

openapi-generator version

<openapi-generator-maven-plugin.version>7.2.0</openapi-generator-maven-plugin.version>

OpenAPI declaration file content or url

schema:
  items:
    format: uuid
    type: string
  minItems: 1
  type: array

Generation Details

<configuration>
  <inputSpec>...</inputSpec>
  <packageName>...</packageName>
  <apiPackage>...</apiPackage>
  <modelPackage>...</modelPackage>
  <generatorName>spring</generatorName>
  <skipIfSpecIsUnchanged>true</skipIfSpecIsUnchanged>
  <generateApiTests>false</generateApiTests>
  <generateModelTests>false</generateModelTests>
  <skipValidateSpec>true</skipValidateSpec>
  <configOptions>
      <useSpringBoot3>true</useSpringBoot3>
      <openApiNullable>false</openApiNullable>
      <interfaceOnly>true</interfaceOnly>
      <useTags>true</useTags>
      <generateBuilders>false</generateBuilders>
      <hideGenerationTimestamp>true</hideGenerationTimestamp>
      <reactive>true</reactive>
      <generatedConstructorWithRequiredArgs>false</generatedConstructorWithRequiredArgs>
      <additionalModelTypeAnnotations>@lombok.Builder(toBuilder = true)
          @lombok.NoArgsConstructor
          @lombok.AllArgsConstructor</additionalModelTypeAnnotations>
  </configOptions>
  <typeMappings>
      <typeMapping>OffsetDateTime=Instant</typeMapping>
  </typeMappings>
  <importMappings>
      <importMapping>java.time.OffsetDateTime=java.time.Instant</importMapping>
  </importMappings>
</configuration>

 @Parameter(name = "UUID") @Valid @Size(min = 1) @RequestBody(required = false) Flux<UUID> uuids,

Suggest a fix

Good fix would be it not being a flux in order to validate it properly. Previous versions (f.e. 5.4.0) just did not add the @Size annotation to it.

Start in the Spring generator's reactive parameter and validation-annotation generation, using the provided array schema and WebFlux configuration as the reproduction. Compare generated output with the 5.4.0 behavior, then verify that minItems does not produce an incompatible @Size annotation on Flux.