(Quick Reference)
                redirect
Purpose
To redirect flow from one action to the next using an HTTP redirect.
Examples
redirect(action: "show")redirect(controller: "book", action: "list")redirect(controller: "book", action: "list", namespace: "publishing")redirect(controller: "book", action: "list", plugin: "publishingUtils")redirect(action: "show", id: 4, params: [author: "Stephen King"])redirect(controller: "book", action: "show", fragment: "profile")redirect(uri: "book/list")redirect(url: "http://www.blogjava.net/BlueSUN")
Description
Redirects the current action to another action, optionally passing parameters and/or errors.  When issuing a redirect from a namespaced controller, the namespace for the target controller is implied to be that of the controller initiating the redirect.  To issue a redirect from a namespaced controller to a controller that is not in a namespace, the namespace must be explicitly specified with a value of 
null as shown below.
class SomeController {
    static namespace = 'someNamespace'    def index() {
        // issue a redirect to PersonController which does not define a namespace
        redirect action: 'list', controller: 'person', namespace: null
    }
}Parameters
- action(optional) - the name of the action to use in the link, if not specified the default action will be linked
- controller(optional) - the name of the controller to use in the link, if not specified the current controller will be linked
- namespace(optional) - the namespace of the controller to redirect to
- plugin(optional) - the name of the plugin which provides the controller
- id(optional) - the id to use in the link
- fragment(optional) - The link fragment (often called anchor tag) to use
- mapping(optional) - The named URL mapping to use to rewrite the link
- params(optional) - a map containing request parameters
- url(optional) - a map containing the action, controller, id etc.
- absolute(optional) - If- truewill prefix the link target address with the value of the- grails.serverURLproperty from- application.groovy, or http://localhost:<port> if there is no value in- application.groovyand not running in the production environment.
- base(optional) - Sets the prefix to be added to the link target address, typically an absolute server URL. This overrides the behaviour of the- absoluteproperty if both are specified.
- permanent(optional) - If- truethe redirect will be issued with a 301 HTTP status code (permanently moved), otherwise a 302 HTTP status code will be issued