A model mapper can be used to convert domain model objects to a more suitable representation.

For example, a Calendar object can be converted to a ZonedDateTime Object.

      
@Bean
public ModelMapper<GregorianCalendar, ZonedDateTime> dateModelMapper() {
  return gregorianCalendar -> Optional.of(gregorianCalendar.toZonedDateTime());
}

    

Beans of type ModelMapper are picked up automatically and configured in the GraphQL wiring Factory.