Hi John (or others using struts on IBM WAS),
I was wondering if you have come accross any other negative implications
besides the nasty show stopping Exception from using struts on WAS.
(work-around provided earlier in thread)
In particular I am concerned that struts makes calls to PageContext -
removeAttribute(String s), while in the Jasper code used by IBM, this will
remove page scope attributes only. Primarily, I am concerned with the
struts class, taglib.logic.IterateTag, which appears to be written to
iterate through attributes at any scope.
Any heads-up about struts on IBM is much appreciated.
Thanks a lot,
Mark
-----Original Message-----
From: Brugge, John [mailto:[EMAIL PROTECTED]]
Sent: Wednesday, July 25, 2001 9:26 AM
To: '[EMAIL PROTECTED]'
Subject: RE: Struts on IBM WAS 4.0 - Error removing attributes from
reques t sc ope!
Pardon my skepticism, but from all appearances, the WAS 4.0 GA release is
out (nothing on the IBM WebSphere site says that the 4.0 you can now
download is beta), and this particular issue is *not* resolved. The
antiquated version of Jasper is still included. And from the response to my
question about this on this list a month ago or so, just dropping in a new
Jasper is not something that's likely to happen quickly. If this issue was
just "brought to their attention a couple of weeks ago" (meaning that they
didn't know about it), I wouldn't hold my breath on a quick resolution.
I'd love to see the fix appear in a fixpack (and soon) but we tried out 4.0
as soon as it was released the end of June, primarily to see if this issue
was resolved, and were disappointed.
John
> -----Original Message-----
> From: Pravin George [SMTP:[EMAIL PROTECTED]]
> Sent: Tuesday, July 24, 2001 9:26 AM
> To: [EMAIL PROTECTED]
> Cc: [EMAIL PROTECTED]
> Subject: RE: Struts on IBM WAS 4.0 - Error removing attributes from
> reques t sc ope!
>
> Hi everyone,
>
> I wanted to clarify the status of Struts and Websphere 4
> compatability. As a business partner to IBM, we are on the beta testing
> program for Websphere 4.0 . This particular issue was brought to their
> attention a couple of weeks ago. Last week we received word that it has
> been fixed in the latest beta build and will not be an issue in the
> final GA release.
>
>
> Pravin George,
> Software Engineer,
> eBuilt Inc. ,
> Irvine, CA 92614.
>
>
>
>
>
> RE: Struts on IBM WAS 4.0 - Error removing attributes from
> reques t sc ope!
> Date:
> Tue, 24 Jul 2001 13:16:48 -0700
> From:
> "Calabrese, Jason" <[EMAIL PROTECTED]>
> Reply-To:
> [EMAIL PROTECTED]
> To:
> "'[EMAIL PROTECTED]'"
> <[EMAIL PROTECTED]>
>
>
>
> I'm running struts on Websphere 3.5.4 and had similar problems.
>
> This is the response I got.
>
> > Check this out..
> >
> http://www.mail-archive.com/struts-user@jakarta.apache.org/msg10964.html
>
> > And..
> > Sure thing - I already sent it but the list refused it due to its file
>
> size.
> > As an alternative, I'll put it up on my personal FTP space and anyone
> who
> > wants it can download it from there! :)
>
> > Struts.jar with Form tag modifications:
> http://www.enfused.com/struts.jar
>
>
> -----Original Message-----
> From: Mark Wilson [mailto:[EMAIL PROTECTED]]
> Sent: Tuesday, July 24, 2001 1:07 PM
> To: '[EMAIL PROTECTED]'
> Subject: Struts on IBM WAS 4.0 - Error removing attributes from request
> sc ope!
>
>
> Hello, thanks for you're attention.
>
> I am deploying the struts-example app on IBM Websphere App Server 4.0
> and
> receive an IllegalArgumentException - Can't remove attribute from
> request
> scope.
>
>
> the situation:
>
> I have drilled into the problem and discovered that IBM is using a
> significantly different implementation of the class,
> org.apache.jasper.runtime.PageContextImpl. Their class alters the logic
>
> of
> removing attributes using the methods removeAttribute(String s, int i)
> and
> removeAttribute(String s).
>
> I have included the code in the next section of the e-mail. In summary,
>
> using WAS 4.0, attributes are not removed from request scope.
>
> This conflicts most directly with the struts framework class,
> org.apache.struts.taglib.html.FormTag. FormTag calls
> pageContext.removeAttribute(Constants.BEAN_KEY,
> PageContext.REQUEST_SCOPE)
> and pageContext.removeAttribute(Constants.FORM_KEY,
> PageContext.REQUEST_SCOPE) within the doEndTag() method.
>
> Either of these method calls will generate an IllegalArgumentException
> on
> WAS 4.0.
>
>
> the code (more or less):
>
> org.apache.jasper.runtime.PageContextImpl (note: not the same code as
> used
> in tomcat's implementation...)
>
> public void removeAttribute(String s, int i)
> {
> switch (i)
> {
> case PAGE_SCOPE:
> pageScopeAttributes.remove(s);
> break;
>
> case REQUEST_SCOPE:
> throw new IllegalArgumentException("Can't remove Attributes
> from
> request scope");
>
> case SESSION_SCOPE:
> if (session == null)
> throw new IllegalArgumentException("Can't access
> SESSION_SCOPE without an HttpSession");
> theSession.removeAttribute(s);
> break;
>
> case APPLICATION_SCOPE:
> theContext.removeAttribute(s);
> break;
> }
> }
>
>
> // and ...
>
> public void removeAttribute(String s)
> {
> pageScopeAttributes.remove(s);
> }
>
> // (pageScopeAttributes is a Hashtable of objects stored at Page
> scope
> only!)
>
>
> a partial solution:
>
> Replacing the removeAttribute(String s, int i) method calls with
> removeAttribute(String s) within the struts class, FormTag.doEndTag()
> relieves the exception, but on WAS 4.0, it will not remove the
> attribute!
> (in fact, only attributes found in page scope will be removed when the
> method, removeAttribute(String s) is called.)
>
>
> testing results:
>
> Even though the attributes weren't removed from the request scope, those
>
> attributes were replaced by new objects the next time. This didn't seem
>
> to
> affect the observable behavior of the struts example application.
>
>
> the question(s):
>
> We really, really want to use struts on WAS 4.0. There seems to be some
>
> logic within struts that relates to "null" attributes.
>
> What are the architectural implications of running an app built upon
> struts
> that will never have it's attributes removed from request scope?
>
> If there are implications, are there ways to work around the problems?
>
> Is it feasible to extend the struts framework to specifically target the
>
> changes noted in WAS 4.0? If so, do you have any recommendations how to
>
> go
> about doing this?
>
>
> Thank you very much,
> Mark
>
>
>
>
