// Here the 'list' action is the default as there is only one action defned
class SampleController {
    def list() {}
}

// In this example 'index' is the default by convention
class SampleController {
    def list() {}
    def index() {}
}

// Here 'list' is explicitly set as the default
class SampleController {
    static defaultAction = 'list'
    def list() {}
    def index() {}
}