Spring. Resolve circular dependency with java config and without @Autowired

Question

I\'ve got circular dependency and java config. While resolving it with xml config is very easy I can\'t resolve it with java config without @Autowired. Beans:

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Answer 1

I want to add another possible solution for your code. Instead of setting circular dependencies right in the config:

@Configuration
public class Config {
    @Bean
    public A a() {
        A a = new A();
        a.setB(b());
        return a;
    }

    @Bean
    public B b() {
        B b = new B();
        b.setA(a());
        return b;
    }
}

You could also let the spring do the work with the power of @Autowired annotation.

@Configuration
public class Config {
    @Bean
    public A a() {
        A a = new A();
        return a;
    }

    @Bean
    public B b() {
        B b = new B();
        return b;
    }
}

public class A {
    private B b;

    @Autowired
    public setB(B b) { this.b = b; }
}

public class B {
    private A a;

    @Autowired
    public setA(A a) { this.a = a; }
}

Of course it is non trivial from the "clean/readable/understandable" point of view because now your configuration is mixed in @Configuration and class itself. But as circular dependencies are quite rare, we could afford the hack.