how to use java custom annotation in openapi spec 3

Question

Just wondering if there is a way I can use my custom annotation in openapi specification.

Scenario-

User Object- I need to have notnull validation between username or email. either one of these should be provided in request

For this I can create a custom annotation in code something like @ValidateUserNameAndEmail, but not finding a way to apply this in openapi spec and include it like other annotation in generated code.

Answer 1

I use the latest version (6.2.1) of openapi-generator-maven-plugin and following works for me.

User:
  type: object
  x-class-extra-annotation: "@org.example.ValidateUsernameAndEmail"
  ...

The plugin generates following class:

@Schema(name = "User ")
@Generated(value = "org.openapitools.codegen.languages.SpringCodegen", date = "2022-11-24T14:51:09.277810200+01:00[Europe/Prague]")
@org.example.ValidateUsernameAndEmail
public class User {
    ...
}

You can also define a field-level annotation using x-field-extra-annotation if needed.