If you have no FilterController
the url localhost/filter
has no ressource to show - so you get a 404 error. You have to adapt your UrlMappings
so that localhost/filter
is a valid url of application.
Add the following to UrlMappings.groovy
:
"/filter" (controller: "yourController", action:"yourAction")
Now - the url localhost/filter
points to yourAction
in yourController
and the filter should be applied.