additional-properties-as-attribute.adoc

In some cases is necessary to use additionalProperties inside the OpenAPI specification, by default this extension creates an object that inherits a java.util.HashMap class. It works well, but there are some issues with Jackson on serialize/deserialize:

• Serialization throws com.fasterxml.jackson.databind.exc.MismatchedInputException exception.

• Deserialization Jackson does ignore plain fields.

If you want to use composition instead inheritance and serialize/deserialize with Jackson without those problems, consider to configure the additional-properties-as-attributes.

To map additionalProperties as attribute, add the following entry to your properties file. In this example, our spec file is in src/main/openapi/petstore.json:

quarkus.openapi-generator.codegen.spec.petstore_json.additional-properties-as-attribute=true

This configuration implies that all models using additionalProperties will be mapped using a java.util.Map as composition.