Regression: @Inherited annotations declared in superclass are not recognized anymore

[amrynsky]

Overview

After migration to spring boot 2.2 we noticed that behavior of the annotations scan has been changed. In our case we define @SpringBootApplication in the base abstract class

@SpringBootApplication
public abstract class BaseApplication {

    protected abstract BaseApplication getApp();

    public void start(String[] args) {
        SpringApplication.run(getApp().getClass(), args);
    }
}

and then multiple concrete applications extend this class

public class DemoApplication extends BaseApplication {
	public static void main(String[] args) {
		new DemoApplication().start(args);
	}

	@Override
	protected BaseApplication getApp() {
		return this;
	}
}

It works fine in the v 2.1.x, but in 2.2 attempt to run the app causes the error:"

java.lang.IllegalArgumentException: No auto-configuration attributes found. Is com.xxx.Application annotated with EnableAutoConfiguration

2019-11-13 09:52:58.571 ERROR 97155 --- [           main] o.s.boot.SpringApplication               : Application run failed

java.lang.IllegalArgumentException: No auto-configuration attributes found. Is com.example.demo.DemoApplication annotated with EnableAutoConfiguration?
	at org.springframework.util.Assert.notNull(Assert.java:215) ~[spring-core-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.getAttributes(AutoConfigurationImportSelector.java:148) ~[spring-boot-autoconfigure-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector.getAutoConfigurationEntry(AutoConfigurationImportSelector.java:115) ~[spring-boot-autoconfigure-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector$AutoConfigurationGroup.process(AutoConfigurationImportSelector.java:396) ~[spring-boot-autoconfigure-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGrouping.getImports(ConfigurationClassParser.java:874) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGroupingHandler.processGroupImports(ConfigurationClassParser.java:801) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorHandler.process(ConfigurationClassParser.java:771) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:188) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:325) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:242) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:275) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:95) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:706) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:532) ~[spring-context-5.2.1.RELEASE.jar:5.2.1.RELEASE]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:747) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) ~[spring-boot-2.2.1.RELEASE.jar:2.2.1.RELEASE]
	at com.example.demo.BaseApplication.start(BaseApplication.java:12) ~[classes/:na]
	at com.example.demo.DemoApplication.main(DemoApplication.java:8) ~[classes/:na]

Steps to reproduce

• use attached demo project to reproduce the issue
  demo.zip
• change spring-boot version to 2.1.8.RELEASE and run app again - everything works as expected

[amrynsky]

It looks like spring-boot v2.2 uses deprecated way to discover annotations org.springframework.core.type.StandardAnnotationMetadata with nestedAnnotationsAsMap set to true. With nestedAnnotationsAsMap = false everything works as expected.

[mbhave]

@philwebb This seems like a bug in Spring Framework. Could you move it there if you agree?

[jhoeller]

@sbrannen Could you look at this one tomorrow? Otherwise I can pick it up on Friday.

[sbrannen]

@sbrannen Could you look at this one tomorrow? Otherwise I can pick it up on Friday.

Sure, I'll take a look and report back to you.

[sbrannen]

Some preliminary debugging reveals the following.

Spring Framework 2.1.8

The StandardAnnotationMetadata.annotations field contains:

• @SpringBootApplication(scanBasePackageClasses=[], exclude=[], excludeName=[], scanBasePackages=[])
• @EnableConfigurationProperties(value=[class com.example.demo.ApplicationConfig])

Spring Framework 5.2.x (master)

The StandardAnnotationMetadata.annotationTypes field contains:

• org.springframework.boot.context.properties.EnableConfigurationProperties

---

So, it appears that @Inherited annotations are no longer taken into account in StandardAnnotationMetadata, since the @Inherited @SpringBootApplication annotation is not visible.

[sbrannen]

@amrynsky, I tested your app locally with the changes I pushed to master, and your app no longer fails to start.

If you'd like to test it on your own, you can test against the latest snapshot builds -- for example, by specifying the following in the <properties> section of your pom.xml:

<spring-framework.version>5.2.2.BUILD-SNAPSHOT</spring-framework.version>

You'll also need to configure the snapshot repo for Maven as follows.

<repository>
    <id>repository.spring.snapshot</id>
    <name>Spring Snapshot Repository</name>
    <url>https://repo.spring.io/snapshot</url>
</repository>

Let us know if you run into any issues.

[amrynsky]

Just tested in several scenarios including our project and everything works as expected.

[sbrannen]

Great! Thanks for letting us know.