j2ee, appservers and lightweight frameworks
I am wondering about one thing regarding j2ee appserver functionality
and more lightweight solutions, for example spring.
In j2ee you would use EJB to do business logic, and servlets to do web
programming. Both of these have their containers and surrounding support
environments that manages their life cycles and resources, such as
thread pools, runtime and configuration management etc. For servlets/jsp
this can be done by using e.g. tomcat and spring. But for the business
logic, is there a replacement to EJB? I know Spring can do a lot of the
same things as EJB, but it seems to me that it lacks the essential
runtime container part of it.
If I want to create an standalone web app, it is possible with spring
and a standalone servlet container. But if I want to create a standalone
business app that does not use a web interface, then it does not seem
possible because there is no runtime environment available, I would have
to program all the plumbing code myself, adding threads pools, runtime
interfaces etc, much the same way the EJB container does, it this correct?