Correct way to use Enums in Groovy and Grails

Question

I want to create a number of global enums that are for use throughout my entire application.

I created a groovy file called enums which looks something like this:

class Enums {
    enum GameType{
        Game1,
        Game2,
        Game3
        Game4
        Game5
    }

    enum Enum2{
        Type1,
        Type2,
        Type3
    }

}

The first enum seems to work fine, but when I try to use the second one I get an 'unable to resolve class' error. What is the correct way to work with Enums in Grails?

Solution

Each enumeration should be in it's own class located under in src/groovy. I would also suggest using a package for them. Your example should be

src/groovy/my/example/GameType.groovy:

package my.example
enum GameType{
  Game1,
  Game2,
  Game3,
  Game4,
  Game5
}

src/groovy/my/example/Enum2.groovy:

package my.example
enum Enum2 {
  Type1,
  Type2,
  Type3
}

Comments

[Burt Beckwith]

You mean /src/groovy not grails-app/src/groovy right?

[Joshua Moore]

Indeed I did. Fixed that. Thanks for the spot check. Guess my brain checked out for a bit.

[Jay Edwards]

In Grails, I tend to use Enums as properties within services; say, if I have an enduring business need to use enum foobar { FOO, BAR } on methods explicitly within FooBarService. However, that is assuming I only want to use that enum within that service (or it is used elsewhere but relates to some common theme of that service - e.g. I'm performing some kind of action with a related Foo and Bar domain Class within a different service). I haven't really found much use for enum beyond that within Grails. Ergo, this is in addendum to the above rather than an answer in itself.