I didn't say that you would know how to use it. You don't need to know, the framework uses it. What I said is that you would know _what_ it is if you ever get a

I didn't say that you would know how to use it. You don't need to know, the framework uses it. What I said is that you would know _what_ it is if you ever get an exception from that class. I'm 95% sure that all those people complaining about Spring never read the reference documentation. I did, and whenever I bump into a problem I have an idea about how to solve it. Besides reading it only takes a few days and you're set for years. Why do anybody expect to be able to work with a technology if they don't bother reading the documentation? This is like complaining about not being able to drive a car when you sit down in the seat without training.