@Primary annotation is not working for beans with the same name [SPR-13980]

[spring-projects-issues]

Modestas Kažinauskas opened SPR-13980 and commented

@Primary annotation is not working for beans. This issue persists in older spring versions too.

Please see my code below

@Configuration
public class ConfigA {
    @Bean
    @Primary
    public MyObject createMyObject() {
        return new MyObject("A");
    }
}

@Configuration
public class ConfigB {
    @Bean
    public MyObject createMyObject() {
        return new MyObject("B");
    }
}

public class MyObject {
    private String name;

    public MyObject(String name) {
        this.name = name;
    }
    ...
}

@Configuration
public class Runner {
    @Autowired
    private MyObject myObject;

    @PostConstruct
    void init() {
        System.out.println(myObject.getName()); //Output is B, but primary bean is A
    }
}

2016-02-25 08:39:49.351 INFO 1196 --- [ main] o.s.b.f.s.DefaultListableBeanFactory : Overriding bean definition for bean 'init' with a different definition: replacing
[Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=true; factoryBeanName=configA; factoryMethodName=createMyObject; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [com/modzo/ConfigA.class]]
with
[Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=configB; factoryMethodName=createMyObject; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [com/modzo/ConfigB.class]]

DefaultListableBeanFactory takes bean name as 'init'. and overrides with another.

This configuration is resolved by changing init method name to not duplicate.

---

Affects: 4.2.4

Reference URL: #15434

Issue Links:

• Reconsider whether to generally allow bean overriding by name [SPR-10808] #15434 Reconsider whether to generally allow bean overriding by name

[spring-projects-issues]

Juergen Hoeller commented

I'm afraid this is working as designed: If you choose the same factory method name (which is usually a meaning bean name such as "accountService", not a generic name like "init"), we assume you intend to override a previously registered bean of the same name... including all of its metadata.

@Primary does not have an effect on this overriding-by-name behavior, since it is only meant to be applied for injection point resolution: i.e. when multiple matching beans have been found in the bean definition registry but only one is to be selected for a particular injection point. This is conceptually very different from overriding bean definitions which leads to hard replacing in the registry, with the previously registered bean not available anymore.

Juergen

[spring-projects-issues]

Modestas Kažinauskas commented

Hi,
thanks for your great explanation.

Could you please specify the link to documentation or design document? It would be very helpful.

Thanks!

[spring-projects-issues]

Modestas Kažinauskas commented

I have changed 'init' to 'createMyObject'.