Is there a compelling reason why the REQUEST_ATTRIBUTES attachment in the exchange requires the values in the Map to be strings?
AttachmentKey<Map<String, String>>
I realize the only place Undertow really uses them is to pass along attribute from the AJP listener. However, I've found several use cases over the years where I want to set up attributes IO handler chain (prior to the servlet) for my servlet to use later. Servlet request attributes are allowed to have any value
Map<String, Object> attributes
This design in Undertow makes it impossible for me to set up request attributes which are not strings in the exchange prior to the servlet. Examples I've run into are SSL certs (javax.servlet.request.X509Certificate) and error exceptions (javax.servlet.error.exception, and javax.servlet.error.exception_type) which can't be set into the REQUEST_ATTRIBUTES attachment.