The biggest difference here is that Spring Boot has the errors in a seperate object BindingResult. If you use Thymeleaf, this is smoothly integrated and you jus

The biggest difference here is that Spring Boot has the errors in a seperate object BindingResult. If you use Thymeleaf, this is smoothly integrated and you just write: <p th:if="${#fields.hasErrors('comment')}">Invalid Comment</p> Grails Framework (Spring Framework more like Rails) integrates errors directly into the domain model, so if you have a domain class Person, it was extended with person.errors property.