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
