session.getValue(key) depreciated - getAttribute does not work

[Anthony Stump]

I'm trying to migrate a Java EE designed app from javax.servlet to jakarta.servlet in order to eventually migrate from Tomcat 9 to 10 (or 11).

I wrote a class to utilize session variables to do a custom DIY login method - probably not secure - but I don't care since it's only on localhost / SSH.

I'm using session.getValue(key) to get the session ID from the client in my Controller file (org.restlet). When I attempt to do session.getAttribute(key) - it breaks everything being returned from any part of the code above it. This causes the Session.jsp endpoint that this class creates to be unreachable, and the login to totally break.

What differences does session.getAttribute(key) have versus session.getValue(key) that would break this, since session.getValue(key) is depreciated?