Struts2 default namespace and root namespace

The default namespace is "Namespace=", "", and the root namespace "namespace="/"".

<package name= "test" extends= "Struts-default" >, if no namespace is specified, the namespace defaults to "Namespace=" ".

The action in the default namespace can handle action requests under any namespace. For example, if there is a request with a URL of/barspace/bar.action and there is no action named bar under the/barspace namespace, then an action named bar under the default namespace will also handle the user request. But the action under the root namespace handles only the request for action under the root namespace, which is the difference between the root namespace and the default namespace.
The namespace has only one level. If the requested URL is/bookservice/search/get.action, the system will first look for an action named get under the/bookservice/search namespace, and if an action named get is found within that namespace, The action handles the user's request, and if it is not found, the system will go directly to the default namespace to look for an action named get, without looking for an action named get under the/bookservice namespace.