Analysis of Spring Source Code (Part 2) — How to resolve circular dependencies

wyr95626@gmail.com (Leafw) — Fri, 19 Feb 2021 00:00:00 +0000

In the last Spring source code analysis, we skipped part of the code on Spring to solve the circular dependency part of the code, in order to fill the hole, I here another article to discuss this issue.

First of all, explain what is circular dependency, in fact, very simple, is that there are two classes they are dependent on each other, as follows.

@Component
public class AService {

    @Autowired
    private BService bService;
}
@Component
public class BService {
  
    @Autowired
    private AService aService;
}

AService and BService are obviously both internally dependent on each other, singled out as if to see the common deadlock code in the multi-threaded, but obviously Spring solves this problem, otherwise we would not be able to use it properly.

Analysis of Spring Source Code (Part 1) — Starting from the Spring Bean Lifecycle

wyr95626@gmail.com (Leafw) — Tue, 02 Feb 2021 00:00:00 +0000

The lifecycle of Spring Beans is really one of the most frequently asked questions about Spring in interviews. I have been stumped by this question more than once. I was wrong to try to rote memorize the steps. On the surface it looks like just reciting a process, but actually many interesting knowledge points are involved in this process.

The following diagram is probably something many people have seen the same or similar:

Spring on Leafw's Blog

Analysis of Spring Source Code (Part 2) — How to resolve circular dependencies

Analysis of Spring Source Code (Part 1) — Starting from the Spring Bean Lifecycle