We're currently migrating some applications from JEE (WebLogic) to Spring Boot, and one of the steps is basically removing almost everything that is JEE. In the end we will probably only use the validation part (because Hibernate validator implements the spec) and JPA.
Spring is for the most part an alternative to Java Enterprise.
The idea is to provide a framework that promotes implementing business logic in plain old java objects, and as much as possible letting the framework deal with the configuration of the various services (data repositories, messaging, transactions etc).
JEE is still a valuable technology, but unless your dealing with large complex systems that require features like distributed transactions [EJB], its is probably overkill.
Spring is an Inversion of Control (IoC) framework. You can create Spring-based apps that have absolutely nothing to do with networking, the Internet, or Enterprise Java.
The JEE-related Spring components are just a small part of an open-ended framework.
So I would assert that it's far more important to understand IoC if you want to learn Spring.
If you do plan on developing Internet-connected apps in Spring, then I would recommend learning JEE, yes. And if you do plan on developing database-connected apps in Spring, I'd recommend learning JDBC. But that's because Spring builds their components on top of standard layers and I think that while having an abstraction mechanism such as Spring is a boon to productivity, knowing what's actually underneath can be a big help in tuning and supporting a Spring-based app.
"privilege" comes from the Latin words for "private" and "law" (legal) and dates to feudal times. To "claim privilege" meant that you were above the laws that applied to the common people.
What's a year in metric? Do you know this metric stuff tiny ad?