What is your idea of a "Java" job in contrast to the "framework" job ? You are taking a very very narrow view. You cannot expect to further your career if you concentrate on just one single technology/language. If you want to work in the general spectrum of Java/J2EE field, you need to know core java &
jsp & servlets & MVC frameworks like struts & spring (most important modules like DI, spring security) & the list goes on.
Point is: No good successful project is JUST java or struts or similar. It consists of almost all the technologies. You HAVE to be good in the basics (core java,jsp,servlets) AND the framework side too. If you concentrate on one thing, you will not be having the bigger picture.
If the current job is not involving enough basics concepts,
you should read the whole Head First JSP/Servlets, and change your company to one which offers you work in those basic stuff.