NoClassDefFoundError in BuildCompatibleExtension

[vbaidak]

Describe the bug

Hi!

I'm trying to integrate the AxonFramework with Quarkus using the Jakarata's BuildCompatibleExtension, which is expected to be fully supported by Quarkus

Basically, I have these 2 classes:

// This class is registered via the SPI in META-INF/services
class AxonExtension : BuildCompatibleExtension {

	@Synthesis
	fun synthesis(syntheticComponents: SyntheticComponents) {
		syntheticComponents.addBean(Configuration::class.java)
			.type(Configuration::class.java)
			.scope(ApplicationScoped::class.java)
			.createWith(AxonConfigurationSyntheticBeanCreator::class.java)
	}

	open class AxonConfigurationSyntheticBeanCreator : SyntheticBeanCreator<Configuration> {
		override fun create(lookup: Instance<Any>, params: Parameters): Configuration =
			DefaultConfigurer.defaultConfiguration().buildConfiguration()
	}

}

@ApplicationScoped
class AxonConfigurer(private val configuration: Configuration) {

	@Startup
	fun startup() {
		configuration.start() // we're failing here
	}

	@Shutdown
	fun shutdown() {
		configuration.shutdown()
	}

}

When the application starts I get the following exception:

2023-11-27 20:36:42,551 ERROR [io.qua.run.Application] (Quarkus Main Thread) Failed to start application (with profile [dev]): java.lang.RuntimeException: Failed to start quarkus
	at io.quarkus.runner.ApplicationImpl.doStart(Unknown Source)
	at io.quarkus.runtime.Application.start(Application.java:101)
	at io.quarkus.runtime.ApplicationLifecycleManager.run(ApplicationLifecycleManager.java:111)
	at io.quarkus.runtime.Quarkus.run(Quarkus.java:71)
	at io.quarkus.runtime.Quarkus.run(Quarkus.java:44)
	at io.quarkus.runtime.Quarkus.run(Quarkus.java:124)
	at io.quarkus.runner.GeneratedMain.main(Unknown Source)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at io.quarkus.runner.bootstrap.StartupActionImpl$1.run(StartupActionImpl.java:113)
	at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.NoClassDefFoundError: axonframework/AxonExtension$AxonConfigurationSyntheticBeanCreator
	at org.axonframework.config.Configuration_c43ae979bb9b4bef9e5e8cd9524490415f9f2b13_Synthetic_Bean.createSynthetic(Unknown Source)
	at org.axonframework.config.Configuration_c43ae979bb9b4bef9e5e8cd9524490415f9f2b13_Synthetic_Bean.doCreate(Unknown Source)
	at org.axonframework.config.Configuration_c43ae979bb9b4bef9e5e8cd9524490415f9f2b13_Synthetic_Bean.create(Unknown Source)
	at org.axonframework.config.Configuration_c43ae979bb9b4bef9e5e8cd9524490415f9f2b13_Synthetic_Bean.create(Unknown Source)
	at io.quarkus.arc.impl.AbstractSharedContext.createInstanceHandle(AbstractSharedContext.java:113)
	at io.quarkus.arc.impl.AbstractSharedContext$1.get(AbstractSharedContext.java:37)
	at io.quarkus.arc.impl.AbstractSharedContext$1.get(AbstractSharedContext.java:34)
	at io.quarkus.arc.impl.LazyValue.get(LazyValue.java:32)
	at io.quarkus.arc.impl.ComputingCache.computeIfAbsent(ComputingCache.java:69)
	at io.quarkus.arc.impl.AbstractSharedContext.get(AbstractSharedContext.java:34)
	at io.quarkus.arc.impl.ClientProxies.getApplicationScopedDelegate(ClientProxies.java:21)
	at org.axonframework.config.Configuration_c43ae979bb9b4bef9e5e8cd9524490415f9f2b13_Synthetic_ClientProxy.arc$delegate(Unknown Source)
	at org.axonframework.config.Configuration_c43ae979bb9b4bef9e5e8cd9524490415f9f2b13_Synthetic_ClientProxy.start(Unknown Source)
	at axonframework.AxonBootstrapper.startup(AxonBootstrapper.kt:19)
	at axonframework.AxonBootstrapper_ClientProxy.startup(Unknown Source)
	at axonframework.AxonBootstrapper_Observer_Synthetic_956ca697e4afd84927d0d5400c3426ddaf02372c.notify(Unknown Source)
	at io.quarkus.arc.impl.EventImpl$Notifier.notifyObservers(EventImpl.java:346)
	at io.quarkus.arc.impl.EventImpl$Notifier.notify(EventImpl.java:328)
	at io.quarkus.arc.impl.EventImpl.fire(EventImpl.java:82)
	at io.quarkus.arc.runtime.ArcRecorder.fireLifecycleEvent(ArcRecorder.java:155)
	at io.quarkus.arc.runtime.ArcRecorder.handleLifecycleEvents(ArcRecorder.java:106)
	at io.quarkus.deployment.steps.LifecycleEventsBuildStep$startupEvent1144526294.deploy_0(Unknown Source)
	at io.quarkus.deployment.steps.LifecycleEventsBuildStep$startupEvent1144526294.deploy(Unknown Source)
	... 13 more
Caused by: java.lang.ClassNotFoundException: axonframework.AxonExtension$AxonConfigurationSyntheticBeanCreator
	at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass(QuarkusClassLoader.java:489)
	at io.quarkus.bootstrap.classloading.QuarkusClassLoader.loadClass(QuarkusClassLoader.java:466)
	... 36 more

Is this an expected behavior or am I doing something wrong?

Expected behavior

Bean successfully registered

Actual behavior

java.lang.NoClassDefFoundError exception is thrown

How to Reproduce?

1. Check out the Project
2. Execute ./gradlew quarkusDev

Output of uname -a or ver

No response

Output of java -version

java version "17.0.6" 2023-01-17 LTS Java(TM) SE Runtime Environment (build 17.0.6+9-LTS-190) Java HotSpot(TM) 64-Bit Server VM (build 17.0.6+9-LTS-190, mixed mode, sharing)

Quarkus version or git rev

3.5.2

Build tool (ie. output of mvnw --version or gradlew --version)

Gradle 8.4

Additional information

No response

[quarkus-bot]

/cc @evanchooly (kotlin), @geoand (kotlin)

[geoand]

cc @Ladicek @mkouba

[Ladicek]

The code looks correct on the first sight. The stack trace shows that the synthetic bean has been registered, the Bean implementation has been generated, the CDI infrastructure behaves as expected, it's "just" that the class is not found at runtime. I'm not sure why off the top of my head; I'll play with the reproducer and report back.

[vbaidak]

@Ladicek , thanks!

I made 2 additional checks:

• the issue reproduces only for ./gradlew quarkusDev launch. When building and running using the jar file java -jar quarkus-axon-issue/build/quarkus-app/quarkus-run.jar everything works
• the issue is somehow connected with dependency. When I add a simple class inside the project and replace axon with it, this bean is successfully added to CDI even when launching with ./gradlew quarkusDev

I also tried setting up quarkus.class-loading.parent-first-artifacts=org.axonframework:axon-configuration, but this didn't help

[Ladicek]

OK, that's interesting to know. Maybe the Bean implementation should explicitly load the creator class from the TCCL, I think we're using a direct class reference right now, which may be wrong. I'll check.

[Ladicek]

OK, so the problem is:

• since the target class for which the synthetic bean is created is a non-application class, the generated Bean implementation is also a non-application class and hence is loaded by the Base Runtime CL
• however, the SyntheticBeanCreator implementation is an application class and hence is loaded by the Runtime CL (a child of the Base Runtime CL)

This means that the generated Bean class doesn't see the implementation of SyntheticBeanCreator.

This is only an issue in dev mode (or test mode), because in prod, class loading is mostly flat (see https://quarkus.io/guides/class-loading-reference).

As a workaround, the target library can be forced into the Runtime CL by setting

quarkus.class-loading.reloadable-artifacts=org.axonframework:axon-configuration

The most straightforward fix would be to turn all Bean classes for synthetic beans registered by build compatible extensions into application classes, but that has consequences (access to package-private methods might not work, hot reload performance might be affected). I think we should only do this for synthetic beans registered by extensions that are in the application. Most of the time, extensions should come from libraries (that is, all extension-related classes would also be non-application), in which case, we don't need (and want) to do anything. I'll try to figure out how to do that, it shouldn't be very hard. In the meantime, the workaround mentioned above should do the trick.

[Ladicek]

Should be fixed by #37397

[vbaidak]

@Ladicek , I tried this setting too: quarkus.class-loading.reloadable-artifacts=org.axonframework:axon-configuration and it didn't help

So, I'll wait for the #37397

[Ladicek]

OK that is really weird. That setting definitely made things work when I tried locally. I confess I translated your reproducer from Kotlin/Gradle/YAML to Java/Maven/properties, to rule out a possible bug in some of these layers; let me try again.

[Ladicek]

That is funny, the documentation for quarkus.class-loading.reloadable-artifacts says:

WARNING: This config property can only be set in application.properties

And indeed, trying to set it in application.yml like this:

quarkus:
  class-loading:
    reloadable-artifacts: org.axonframework:axon-configuration

doesn't work. I don't know why, but renaming application.yml to application.properties and changing the content to

quarkus.class-loading.reloadable-artifacts=org.axonframework:axon-configuration

did help. Go figure 🤷

In any case, the PR should help.