Spring tries to instantiate nested annotation with a @Component annotation [SPR-8761]

[spring-projects-issues]

Stefan Gybas opened SPR-8761 and commented

When a component-scanned class has a nested annotation with a @Component annotation, Spring 3.1 RC1 tries to instantiate the nested annotation. For example:

// the test passes if you remove this annotation
@Component
public class WithNestedAnnotation {

    @Target({ ElementType.TYPE })
    @Retention(RetentionPolicy.RUNTIME)
    @Documented
    @Component
    public static @interface MyComponent {

        String value() default "";
    } 
}

@WithNestedAnnotation.MyComponent
public class UsesAnnotation {

}

fails with

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.example.WithNestedAnnotation$MyComponent#0': Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.example.WithNestedAnnotation$MyComponent]: Specified class is an interface
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:990)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:936)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:488)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:459)
	at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
	at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:103)
	at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:1)
	at org.springframework.test.context.support.DelegatingSmartContextLoader.loadContext(DelegatingSmartContextLoader.java:228)
	at org.springframework.test.context.TestContext.loadApplicationContext(TestContext.java:124)
	at org.springframework.test.context.TestContext.getApplicationContext(TestContext.java:148)
	... 24 more
Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.example.WithNestedAnnotation$MyComponent]: Specified class is an interface
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:56)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:983)
	... 39 more

This works fine with Sping 3.0.6 so it's a regression in 3.1 RC1. When you move the @Component annotation from MyComponent to UsesAnnotation it also works with 3.1RC1.

Attached is a Maven/Eclipse project with a test that demonstrates the problem.

---

Affects: 3.1 M2, 3.1 RC1

Attachments:

• NestedAnnotationTest.zip (5.97 kB)

[spring-projects-issues]

Chris Beams commented

Hi Stefan,

Thanks for the reproduction project.

This is definitely a regression as you pointed out. It works against 3.1.0.M1, and begins failing with 3.1.0.M2. I think I know what it is; should have it wrapped up for RC2.

Thanks

Chris

[spring-projects-issues]

Chris Beams commented

Note that I've added the test case to the issues repo at https://github.com/SpringSource/spring-framework-issues/tree/master/SPR-8761

[spring-projects-issues]

Chris Beams commented

Stefan, this is fixed. Please take a look and confirm if you can; we'll be releasing RC2 shortly.

[spring-projects-issues]

Stefan Gybas commented

Hi Chris,

I can confirm that it's fixed in 3.1 RC2. Thanks!

Stefan