OpenAPITools/openapi-generator · error · IllegalArgumentException

useJspecify is only suppored in these libraries: {JSPECIFY_S

Error message

useJspecify is only suppored in these libraries: {JSPECIFY_SUPPORTED_LIBRARIES}

What it means

Error "useJspecify is only suppored in these libraries: {JSPECIFY_SUPPORTED_LIBRARIES}" thrown in OpenAPITools/openapi-generator.

Source

Thrown at modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/JavaClientCodegen.java:346

        // Ensure the OAS 3.x discriminator mappings include any descendent schemas that allOf
        // inherit from self, any oneOf schemas, any anyOf schemas, any x-discriminator-values,
        // and the discriminator mapping schemas in the OAS document.
        this.setLegacyDiscriminatorBehavior(false);

        initMpRestClientVersionToRootPackage();
    }

    private void initMpRestClientVersionToRootPackage() {
        mpRestClientVersions.put("1.4.1", new MpRestClientVersion("javax", "pom.mustache"));
        mpRestClientVersions.put("2.0", new MpRestClientVersion("javax", "pom.mustache"));
        mpRestClientVersions.put("3.0", new MpRestClientVersion("jakarta", "pom_3.0.mustache"));
    }

    @Override
    public void setUseJspecify(boolean useJspecify) {
        // currently only available for a limited set of libraries
        if (useJspecify && !JSPECIFY_SUPPORTED_LIBRARIES.contains(library)) {
            throw new IllegalArgumentException("useJspecify is only suppored in these libraries: " + JSPECIFY_SUPPORTED_LIBRARIES);
        }
        super.setUseJspecify(useJspecify);
    }

    @Override
    public CodegenType getTag() {
        return CodegenType.CLIENT;
    }

    @Override
    public String getName() {
        return "java";
    }

    @Override
    public String getHelp() {
        return "Generates a Java client library (HTTP lib: Jersey (1.x, 2.x), Retrofit (2.x), OpenFeign (10.x) and more.";
    }

View on GitHub (pinned to fcec517be3)

Solutions

1. Set useJspecify only with one of the libraries listed in JSPECIFY_SUPPORTED_LIBRARIES, or remove the useJspecify option.

When it happens

Trigger: Thrown when useJspecify=true is set for the Java client generator with a library that does not support JSpecify annotations. Use one of the libraries listed in the message.

Common situations: See trigger scenarios.

AI-assisted analysis of OpenAPITools/openapi-generator@fcec517be3 (2026-08-22). Data as JSON: /api/errors/4921125ac80fd87f. Report an issue: GitHub.