Dialect overwrite

This shows how to effectively overwrite draft4 dialect and treat it as draft2020-12 dialect.

Example of schema definition

Notice that $id was not a valid keyword in draft4, so it wouldn't be accessible under urn:schema URI, if not for the dialect overwrite.

{
  "$id": "urn:schema",
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "null"
}

Validator configuration

Validator validator = new ValidatorFactory()
        .withDialect(new Dialects.Draft2020Dialect() {
            @Override
            public String getMetaSchema() {
                return SpecificationVersion.DRAFT4.getId();
            }
        })
        .createValidator();
validator.registerSchema(schema);
Validator.Result res = validator.validate(URI.create("urn:schema"), "\"test\"");

04 August 2025