13 The Service Layer

Grails defines the notion of a service layer. The Grails team discourages the embedding of core application logic inside controllers, as it does not promote reuse and a clean separation of concerns.

Services in Grails are the place to put the majority of the logic in your application, leaving controllers responsible for handling request flow with redirects and so on.

Creating a Service

You can create a Grails service by running the create-service command from the root of your project in a terminal window:

grails create-service helloworld.simple

The above example will create a service at the location grails-app/services/helloworld/SimpleService.groovy. A service’s name ends with the convention Service, other than that a service is a plain Groovy class:

package helloworld
class SimpleService {
}