Basically, I want to be able to assign objects created within filters to members in a base controller from which every controller extends. Any possible way to do that?

Here's how I tried, but haven't got to make it work.

What I'm trying to achieve is to have all my controllers extend a base controller. The base controller's constructor would be used to assign values to its members, those values being pulled from the session map. Example below.

File grails-app/controllers/HomeController.groovy:

class HomeController extends BaseController {
    def index = {
        render username
    }
}

File grails-app/controllers/BaseController.groovy:

abstract class BaseController {
    public String username

    public BaseController() {
        username = session.username
    }
}

When running the app, the output shown is:

2010-06-15 18:17:16,671 [main] ERROR [localhost].[/webapp]  - Exception sending context initialized event to listener instance of class org.codehaus.groovy.grails.web.context.GrailsContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'pluginManager' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Invocation of init method failed; nested exception is java.lang.RuntimeException: Unable to locate constructor with Class parameter for class org.codehaus.groovy.grails.commons.DefaultGrailsControllerClass
    ...
Caused by: java.lang.RuntimeException: Unable to locate constructor with Class parameter for class org.codehaus.groovy.grails.commons.DefaultGrailsControllerClass
    ...
Caused by: java.lang.reflect.InvocationTargetException
    ...
Caused by: org.codehaus.groovy.grails.exceptions.NewInstanceCreationException: Could not create a new instance of class [com.my.package.controller.HomeController]!
    ...
Caused by: groovy.lang.MissingPropertyException: No such property: session for class: com.my.package.controller.HomeController
    at com.my.package.controller.BaseController.<init>(BaseController.groovy:16)
    at com.my.package.controller.HomeController.<init>(HomeController.groovy)
    ...
2010-06-15 18:17:16,687 [main] ERROR core.StandardContext  - Error listenerStart
2010-06-15 18:17:16,687 [main] ERROR core.StandardContext  - Context [/webapp] startup failed due to previous errors

And the app won't run.

This is just an example as in my case I wouldn't want to assign a username to a string value, but rather a few objects pulled from the session map. The objects pulled from the session map are being set within filters.

The alternative I see is being able to access the controller's instance within the filter's execution. Is that possible?

Please help! Thanks a bunch!