Self-injection in configuration class hierarchies broken [SPR-10668]

[spring-projects-issues]

Oliver Drotbohm opened SPR-10668 and commented

Assume you have a configuration class autowiring a component a subclass of this config class might declare:

@Configuration
class ParentConfig {

  @Autowired(required = false) MyComponent component;
}

@Configuration
class ChildConfig extends ParentConfig {

  @Bean
  public MyComponentImpl myComponent() { … }
}

This fails with a rather ambiguous:

Caused by: java.lang.IllegalArgumentException: Object of class [null] must be an instance of interface org.springframework.beans.factory.config.ConfigurableBeanFactory
  at org.springframework.util.Assert.isInstanceOf(Assert.java:339)
  at org.springframework.util.Assert.isInstanceOf(Assert.java:319)
  at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.getBeanFactory(ConfigurationClassEnhancer.java:414)
  at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:289)
  at de.olivergierke.samples.spring.ConfigClassExtensionTest$ChildConfig$$EnhancerByCGLIB$$769c39d2.myComponent(<generated>)

This seems to be caused by the fix for #14941. Previously a BeanFactory instance had been available at the point in time when the autowiring happens. As of the change, the BeanFactory will be injected through an BeanFactoryAware call which by Spring's lifecycle happens after property injection. Thus the required BeanFactory is null when the injection shall happen and thus it fails.

I have an executable sample for this at http://github.com/olivergierke/spring-samples. Steps to reproduce:

1. Clone the repo:
2. Run mvn clean test -> works
3. Upgrade Spring version in the pom.xml to 4.0.0.BUILD-SNAPSHOT
4. Run mvn clean test -> fails

---

Issue Links:

• DATAGRAPH-363 Spring Data Neo4j doesn't work with Spring 4.0.0.BUILD-SNAPSHOT ("is depended on by")
• NPE in LoadTimeWeavingConfiguration: loadTimeWeaver() called too early [SPR-14931] #19498 NPE in LoadTimeWeavingConfiguration: loadTimeWeaver() called too early

Referenced from: commits a403e8f

[spring-projects-issues]

Phil Webb commented

Hi Oliver,

Thanks for the excellent analysis, it helped a lot.

I have committed a fix that resolves the test case but I would appreciate it if you could double check the latest snapshot against DATAGRAPH-363.

Cheers.