Both framework have their own advantage and disadvantage, we can select these framework according to the requirement of the project (which framework fits for the project).
Grails is an open source web application framework which uses the Groovy programming language. It is intended to be a high-productivity framework by following the "coding by convention" paradigm, providing a stand-alone development environment and hiding much of the configuration detail from the developer.
Like Rails, Grails seems to be what I call "Strongly Grained". If you do things the Grails way, development is easy (and generally quite fast). The framework tends to have a preferred way of doing most things. On the other hand, if you need to go against the grain, you'll have a comparably rough time of it.
Spring Boot makes it easy to create stand-alone, production-grade Spring based Applications that you can "just run". We take an opinionated view of the Spring platform and third-party libraries so you can get started with minimum fuss. Most Spring Boot applications need very little Spring configuration.
