[jira] Commented: (WW-2101) PreparatorServlet causes request and response objects to be used outside of service() method

["Aleksander Adamowski (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/struts/browse/WW-2101?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_42791 ] 

Aleksander Adamowski commented on WW-2101:
------------------------------------------

Don't you think that removing Preparator and ServletContextHolderListener without even noting it in release notes (http://struts.apache.org/2.0.11/docs/release-notes-2010.html, http://struts.apache.org/2.0.11/docs/release-notes-2011.html) is a bit irresponsible?

The Maven archtypes which provide example projects (e.g. struts2-archetype-portlet) contain references to those classes in web.xml and they get broken when updating struts2-core JAR to 2.0.10 or 2.0.11.

The example web.xml contains this:

    <listener>
		<listener-class>
			org.apache.struts2.portlet.context.ServletContextHolderListener
		</listener-class>
	</listener>

	<servlet id="preparator">
		<servlet-name>preparator</servlet-name>
		<servlet-class>
			org.apache.struts2.portlet.context.PreparatorServlet
		</servlet-class>
	</servlet>


What to do in 2.0.10 an later? Simply remove the listener and preparator? Won't something break in a mysterious way?


> PreparatorServlet causes request and response objects to be used outside of service() method
> --------------------------------------------------------------------------------------------
>
>                 Key: WW-2101
>                 URL: https://issues.apache.org/struts/browse/WW-2101
>             Project: Struts 2
>          Issue Type: Bug
>          Components: Plugin - Portlet
>            Reporter: Rickard Öberg
>            Assignee: Nils-Helge Garli
>            Priority: Critical
>             Fix For: 2.0.10, 2.1.0
>
>
> The PreparatorServlet stores the request and response object to be used later. The servlet spec (SRV.2.3.3.3) states the following:
> "References to the request and response objects should not be given to objects
> executing in other threads as the resulting behavior may be nondeterministic. If
> the thread created by the application uses the container-managed objects, such as
> the request or response object, those objects must be accessed only within the
> servlet's service life cycle and such thread itself should have a life cycle within
> the life cycle of the servlet's service method because accessing those objects
> after the service method ends may cause undeterministic problems."
> So, it is not legal to store those objects as there is no way to know that the objects are valid after the service() invocation. And indeed, in our portal container implementation those object are immediately invalidated after the service() method, causing deterministically problematic situations for our users that has chosen Struts 2.
> I understand that the whole idea of using PreparatorServlet is to get a reference to ServletRequest and ServletResponse objects, but it is not a valid way to do it. It would probably be better if it was possible to simple implement wrapper objects that work with the PortletRequest and PortletResponse objects instead, in the portlets render() method.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.