EventListener in DelegatingEventExternalizer could not be created - Similar To Issue 973

[ashwinibuche]

When using Spring Modulith 1.3.3 (starter + events-core + NATS Event) with Spring Boot 3.4.3, the auto-configured DelegatingEventExternalizer instance 'natsEventExternalizer' , continuously receiving EventListenerMethodProcessor can not find the @ApplicationModuleListener annotated method on, resulting in the following stacktrace:

org.springframework.beans.factory.BeanInitializationException: Failed to process @EventListener annotation on bean with name 'natsEventExternalizer': Need to invoke method 'externalize' declared on target class 'DelegatingEventExternalizer', but not found in any interface(s) of the exposed proxy type. Either pull the method up to an interface or switch to CGLIB proxies by enforcing proxy-target-class mode in your configuration.
	at org.springframework.context.event.EventListenerMethodProcessor.afterSingletonsInstantiated(EventListenerMethodProcessor.java:149) ~[spring-context-6.2.3.jar:6.2.3]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:1083) ~[spring-beans-6.2.3.jar:6.2.3]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:987) ~[spring-context-6.2.3.jar:6.2.3]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:627) ~[spring-context-6.2.3.jar:6.2.3]
	at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:146) ~[spring-boot-3.4.3.jar:3.4.3]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:752) ~[spring-boot-3.4.3.jar:3.4.3]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:439) ~[spring-boot-3.4.3.jar:3.4.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:318) ~[spring-boot-3.4.3.jar:3.4.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1361) ~[spring-boot-3.4.3.jar:3.4.3]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1350) ~[spring-boot-3.4.3.jar:3.4.3]
	at org.rockwell.publishermodulith.main(publishermodulith.java:14) ~[classes/:na]
Caused by: java.lang.IllegalStateException: Need to invoke method 'externalize' declared on target class 'DelegatingEventExternalizer', but not found in any interface(s) of the exposed proxy type. Either pull the method up to an interface or switch to CGLIB proxies by enforcing proxy-target-class mode in your configuration.
	at org.springframework.core.MethodIntrospector.selectInvocableMethod(MethodIntrospector.java:135) ~[spring-core-6.2.3.jar:6.2.3]
	at org.springframework.aop.support.AopUtils.selectInvocableMethod(AopUtils.java:150) ~[spring-aop-6.2.3.jar:6.2.3]
	at org.springframework.context.event.EventListenerMethodProcessor.processBean(EventListenerMethodProcessor.java:189) ~[spring-context-6.2.3.jar:6.2.3]
	at org.springframework.context.event.EventListenerMethodProcessor.afterSingletonsInstantiated(EventListenerMethodProcessor.java:145) ~[spring-context-6.2.3.jar:6.2.3]
	... 10 common frames omitted

Process finished with exit code 1

[ashwinibuche]

I am attaching the project workspace in this issue which is maven based

[ashwinibuche]

ModulithExternalization.zip

ModulithExternalization.zip

[ashwinibuche]

both the zip files are the same

[odrotbohm]

I can't start any of the projects contained in the zip. Please reduce the content of the ZIP as much as possible. And make sure that any simple Maven command (mvn clean verify or mvn spring-boot:run) reproduces the error.

The exception looks like something is enabling JDK proxying of the ElegatingEventExternalizer bean, and I am unsure what that is.

[ashwinibuche]

@odrotbohm thanks for your revert.

mvn spring-boot:run does reproduce the error. Please find the attached snapshot of the powershell. I have reduced the file size now. Hope you would be able to extract the file at your end

[ashwinibuche]

I am attaching my workspace over here

ModulithExternalization.zip

[porlikowski]

I had the same issue as You mentioned. Try to add

 <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-jpa</artifactId>
    </dependency>

    <dependency>
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
        <scope>runtime</scope>
    </dependency>

to Your dependencies it works for me. But i didn't find solution. @odrotbohm maybe it will help You with debugging.
As far as i've checked it it is connected with database transacion and outbox pattern in it.

[odrotbohm]

Folks, I can't spend time hunting down multi-module project zip files to reproduce an error. The latest zip's content fails on mvn clean verify with:

/ModulithExternalization 2/publisher/src/main/java/org/rockwell/publish/MessageController.java:[64,50] incompatible types: org.rockwell.externalized.PhaseStartableEvent cannot be converted to org.rockwell.IEvent

Remember: this is a bug tracker, no support forum. So you either have a minimal reproducer (single module, as few as possible dependencies, easy to execute to show the failure) or, I am afraid, I don't have the time to investigate what you claim is broken.

[porlikowski]

modulith-Issue-973.zip

[porlikowski]

but in my opinion its not a bug. It works as expected because its based on transactions connected to kafka producer. In my opinion nice to have would be to send message without outbox pattern depends on configuration if able .