指定关闭时的 bean 销毁顺序

Question

I am currently working on a spring project and I have two beans Let's say Bean A and Bean B

I want to make sure

1. Bean A is created before Bean B
2. Bean A is destroyed after destroying Bean B

In simple terms, Bean A should exist for the entire lifecycle of Bean B

Is it possible to configure this?

Answer 1

Please look at below mentioned example, here Class A(Service Bean) will always be created after B as B(repository Bean) available as dependency to A, otherwise it will give exception. After usage of Bean B it will be destroyed as there is not significance in storing it. That is how it is design in Framework itself and it is best approach I cannot think of scenario where it is required.

Even if it is required then check out Bean Scopes as this teaches excellent way to define bean life span as per requirement. Please find documentation for bean scopes .

 @Service
    public class A{
        private B repository;
        
        @Autowired
        public A(B repository) {
            super();
            this.repository = repository;
        }
    .....//(Rest of code)
    }

    public interface B extends JpaRepository<User, Long> {
    .....//Rest of method declaration
    }