With regard to CDI scopes and servlets, I think it would be a really REALLY bad idea to try and support scopes for servlets and filters.
A request scoped servlet would essentially be much the same as a javax.servlet.SingleThreadModel servlet - which was a bad idea then and is still a bad idea now
It's of course not just requests scope, but scopes like the view scope, client window scope, conversation scope, etc and whatever custom scope people can think of.
Why is this level of integration needed to be supported in the servlet container itself.
I think perhaps because Servlet is part of Jakarta EE, and Jakarta EE moves to CDI. In Jakarta EE a Servlet is already a Jakarta Managed Bean (
https://jakarta.ee/specifications/managedbeans/2.0/jakarta-managed-beans-spec-2.0), so moving it to CDI seems reasonable. Of course, only when running within a Jakarta EE environment. For Tomcat, Jetty, Piranha-Servlet and other standalone containers this would never be mandated.
Integrating web frameworks into servlets has been and will be a mistake.
I'm not really sure which web framework would have to be integrated in servlets. There are only two in scope from the Jakarta perspective: Jakarta Faces and Jakarta MVC and neither have that need AFAIK.
Kind regards,
Arjan
