Spring-boot: Override RabbitListenerAnnotationBeanPostProcessor default bean doesn't work in spring-boot v2.1.4.RELEASE

[juliofalbo]

Good night.

I have a library that extends Spring AMQP and changes the default Autoconfiguration file (I will open source it).

But when I migrate to Spring Boot 2.1.4, the method that is responsible to change the RabbitListenerAnnotationBeanPostProcessor behavior simply stop to be called.

@Primary
@Bean(name = RabbitListenerConfigUtils.RABBIT_LISTENER_ANNOTATION_PROCESSOR_BEAN_NAME)
@Role(BeanDefinition.ROLE_APPLICATION)
@DependsOn(RabbitConstants.CONNECTION_FACTORY_BEAN_NAME)
public RabbitListenerAnnotationBeanPostProcessor rabbitListenerAnnotationProcessor() {
    return new NewRabbitListenerAnnotationBeanPostProcessor();
}

This method belongs to a class that I defined to be the default Autoconfiguration file.

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
org.springframework.boot.autoconfigure.amqp.NewRabbitAutoConfiguration

@Configuration
@ConditionalOnClass({ RabbitTemplate.class, Channel.class })
@EnableConfigurationProperties({ RabbitProperties.class, RabbitCustomPropertiesMap.class })
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE)
@Import(RabbitAnnotationDrivenConfiguration.class)
public class NewRabbitAutoConfiguration {
...
}

So, if I can't call my NewRabbitListenerAnnotationBeanPostProcessor I will be a problem because I have some treats for the attribute containerFactory of RabbitListener annotation.

---

UPDATE 1

I think the problem is: RabbitListenerAnnotationBeanPostProcessor is executing before the new AutoConfiguration class (NewRabbitAutoConfiguration)

UPDATE 2

I tried to annotate the bean of my Listener with @ConditionalOnBean(NewRabbitAutoConfiguration.class), but the result was very strange, Spring called all methods of the NewRabbitAutoConfiguration but not call the rabbitListenerAnnotationProcessor method (and the bean RabbitConstants.CONNECTION_FACTORY_BEAN_NAME) was created.

UPDATE 3

I've created a repo to simulate the problem: https://github.com/juliofalbo/spring-2.1.4-bug-override-bean-post-processor

Note: If we change the version of Spring Boot to 2.1.3.RELEASE, works fine!

---

Can someone help me with this issue?

[philwebb]

I'm not sure what exactly has changed between 2.1.3 and 2.1.4 but your configuration looks quite unusual and I wouldn't recommend taking such an approach.

Specifically:

• Trying to directly import auto-configuration delegate classes is quite brittle
• You should not use a package named org.springframework.boot.autoconfigure.amqp in an open source project. The org.springframework package is reserved for official Spring projects.
• Requiring users to have spring.main.allow-bean-definition-overriding=true is not recommended
• Having @AutoConfigureOrder of HIGHEST is likely going to cause problems
• Your rabbitListenerAnnotationProcessor method might cause some initialization issues since it's a bean post processor that depends on a connection factory.

Instead I think it might be better to structure your configuration like this:

@Configuration
@ConditionalOnClass({ RabbitTemplate.class, Channel.class })
@AutoConfigureBefore(RabbitAutoConfiguration.class)
@Import({NewRabbitAutoConfiguration.RabbitPostProcessorConfiguration.class, RabbitAnnotationDrivenConfiguration.EnableRabbitConfiguration.class})
public class NewRabbitAutoConfiguration {

    @Configuration
    static class RabbitPostProcessorConfiguration {

        @Bean(name = RabbitListenerConfigUtils.RABBIT_LISTENER_ANNOTATION_PROCESSOR_BEAN_NAME)
        public static RabbitListenerAnnotationBeanPostProcessor rabbitListenerAnnotationProcessor() {
            return new NewRabbitListenerAnnotationBeanPostProcessor();
        }

    }

    @Configuration
    @EnableRabbit
    static class EnableRabbitConfiguration {

        @Bean(name = RabbitListenerConfigUtils.RABBIT_LISTENER_ANNOTATION_PROCESSOR_BEAN_NAME)
        public static RabbitListenerAnnotationBeanPostProcessor rabbitListenerAnnotationProcessor() {
            return new NewRabbitListenerAnnotationBeanPostProcessor();
        }

    }
}

This will create a configuration that's ordered to run before ours (because of @AutoConfigureBefore(RabbitAutoConfiguration.class)). It will import a couple of configuration in a specific order. The first will register your post processor and the second will enable rabbit.

The @EnableRabbit annotation triggers RabbitBootstrapConfiguration but this won't replace your post processor because it has an explicit check. When our auto-configuration runs it backs-off because it already finds a post processor.

[juliofalbo]

Hi Phil!
Thank you very much for your quick help!

Perfect, I'm sorry about the package, I didn't know about this info, but one question.
How can I access the RabbitAnnotationDrivenConfiguration.class in another package? This class is not public. :(

[wilkinsona]

I don't think you need to so do. Phil is proposing that you have your own EnableRabbitConfiguration so you can drop the import of RabbitAnnotationDrivenConfiguration.EnableRabbitConfiguration.class.

[juliofalbo]

Perfect Andy!

Thank you very much everyone!

[juliofalbo]

Hi, I have another question.

Phil said that requiring users to have spring.main.allow-bean-definition-overriding=true is not recommended, and I agree 100%, but there is another way to avoid this?

Thank you very much all support!

[philwebb]

@juliofalbo I don't think it's needed with the sample I gave above because rather than replacing beans, you version registers them first and the other configurations just back off.