Spring
ExplainedFramework
Also known as: Spring Framework
Comprehensive Java framework with dependency injection, AOP and integration modules for enterprise applications.
Spring, explained
Written by EduVerseWhat it is
Spring is a framework for building Java applications, mostly backends. Its core is a container that creates your objects (called beans) and hands each one the other objects it needs, which is known as dependency injection. Around that core sit modules for web APIs, database access, security and messaging.
Why teams use it
Wiring hundreds of classes together by hand gets messy and hard to test. Spring takes over that wiring and gives teams the same patterns for transactions, security and data access. Jakarta EE, Quarkus and Micronaut cover similar ground, but Spring has been around so long that most problems you hit are already solved and documented.
An example from work
You open OrderService in your team’s backend and see @Service above the class and a constructor that takes an OrderRepository, yet nothing ever calls new OrderService(). Spring creates it at startup. Forget that annotation on a class another class needs, and the app won’t start: the log says “No qualifying bean of type”.
Our own explanation, not a quote from the book.
Where it fits
Enterprise Java applications, the foundation of Spring Boot
Coverage in the book
Explained and compared with alternatives, so you know where and why it’s used.
