spring-tx causes cglib error in java native runtime for repository beans defined by interface

[jzhn]

What

Spring boot uses AOT processing to generate required reflect/proxy/resource configs as well as CGLIB proxy classes in compile time. For beans defined with interface types, CGLIB proxy is usually unnecessary so process-aot job does not generate CGLIB proxy.

When org.springframework.data:spring-data-mongodb is imported, java native projects with repository beans defined with interface types will encounter exception in runtime about unexpected CGLIB usage for the repository class.

Update: upon further investigation, just having org.springframework:spring-tx is enough to trigger the issue. It's not directly caused by spring-data-mongodb.

Minimum reproduciable project

https://github.com/jzhn/springNativeBugSpringDataMongoDB. Please refer to its README for steps to reproduce, expected behaviour and actual behaviour.

Versions

• JDK: 21.0.2-graalce
• Spring-Boot: 3.4.2 (latest to date)
• MacOS 15.2 on ARM64 mac

[snicoll]

@jzhn thanks for the report and the reproducer. Here is the stacktrace:

2025-01-28T10:19:50.461+01:00  WARN 27662 --- [demo] [           main] o.s.c.support.GenericApplicationContext  : Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'demoApplication': Unsatisfied dependency expressed through constructor parameter 0: Error creating bean with name 'myDao': Unexpected AOP exception
Application run failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'demoApplication': Unsatisfied dependency expressed through constructor parameter 0: Error creating bean with name 'myDao': Unexpected AOP exception
	at org.springframework.beans.factory.aot.BeanInstanceSupplier.resolveAutowiredArgument(BeanInstanceSupplier.java:369)
	at org.springframework.beans.factory.aot.BeanInstanceSupplier.resolveArguments(BeanInstanceSupplier.java:289)
	at org.springframework.beans.factory.aot.BeanInstanceSupplier.get(BeanInstanceSupplier.java:223)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.obtainInstanceFromSupplier(DefaultListableBeanFactory.java:979)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.obtainFromSupplier(AbstractAutowireCapableBeanFactory.java:1243)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1186)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:563)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:523)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:336)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:307)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:334)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.instantiateSingleton(DefaultListableBeanFactory.java:1122)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingleton(DefaultListableBeanFactory.java:1093)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:1030)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:987)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:627)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:752)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:439)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:318)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1361)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1350)
	at com.example.demo.DemoApplication.main(DemoApplication.java:18)
	at java.base@21.0.5/java.lang.invoke.LambdaForm$DMH/sa346b79c.invokeStaticInit(LambdaForm$DMH)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'myDao': Unexpected AOP exception
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:608)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:523)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:336)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:307)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:334)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:254)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1631)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1519)
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:913)
	at org.springframework.beans.factory.support.RegisteredBean.resolveAutowiredArgument(RegisteredBean.java:253)
	at org.springframework.beans.factory.aot.BeanInstanceSupplier.resolveAutowiredArgument(BeanInstanceSupplier.java:366)
	... 23 more
Caused by: org.springframework.aop.framework.AopConfigException: Unexpected AOP exception
	at org.springframework.aop.framework.CglibAopProxy.buildProxy(CglibAopProxy.java:243)
	at org.springframework.aop.framework.CglibAopProxy.getProxy(CglibAopProxy.java:167)
	at org.springframework.aop.framework.ProxyFactory.getProxy(ProxyFactory.java:110)
	at org.springframework.aop.framework.AbstractAdvisingBeanPostProcessor.postProcessAfterInitialization(AbstractAdvisingBeanPostProcessor.java:127)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyBeanPostProcessorsAfterInitialization(AbstractAutowireCapableBeanFactory.java:439)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1815)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:601)
	... 34 more
Caused by: java.lang.UnsupportedOperationException: CGLIB runtime enhancement not supported on native image. Make sure to include a pre-generated class on the classpath instead: com.example.demo.MongoDao$$SpringCGLIB$$0
	at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:363)
	at org.springframework.cglib.proxy.Enhancer.generate(Enhancer.java:575)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.lambda$new$1(AbstractClassGenerator.java:107)
	at org.springframework.cglib.core.internal.LoadingCache.lambda$createEntry$1(LoadingCache.java:52)
	at java.base@21.0.5/java.util.concurrent.FutureTask.run(FutureTask.java:317)
	at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:57)
	at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:130)
	at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:317)
	at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:562)
	at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:407)
	at org.springframework.aop.framework.ObjenesisCglibAopProxy.createProxyClassAndInstance(ObjenesisCglibAopProxy.java:62)
	at org.springframework.aop.framework.CglibAopProxy.buildProxy(CglibAopProxy.java:228)
	... 40 more

FTR, I don't believe that #32609 is linked to this.

[snicoll]

I didn't look carefully enough at the sample and missed the comment you added in the configuration file:

    // replace above with below to workaround the issue
    // since defining bean with concreate type would 
    // make process-aot generate the required cglib proxy  
    // @Bean
    // public MongoDao myDao() {
    //     return new MongoDao();
    // }

This is what you should be doing. If you expose a type that does not provide the capabilities that are needed at runtime, Spring AOT will not get a chance to prepare the object to honor them.

[jzhn]

@snicoll thanks for the quick triage and apologies for missing the doc about returning precise bean types.

For my learning - is it possible to implement some sort of generic logic to generate and register the CGLIB bean types manually? The reason I'm asking that is my org is doing a massive conversion to java native + springboot. So if there's a chance that such logic can be handled centrally, it could save teams some efforts of updating all of their configurations. For example, if teams know a certain package, like com.foo.repository, will contain Repository beans that would be exposed via interface typed beans in configurations, then we can do a class path scan and create CGLIB proxies for all classes during spring AOT.

[snicoll]

For my learning - is it possible to implement some sort of generic logic to generate and register the CGLIB bean types manually?

I suppose that would be possible. However, creating the proxy is the least of your problem. Anything that requires the framework to act on the instance needs to be known at build time. If you have a @Autowired member of the implementation and you return the interface, we won't know at build time the member needs to be called to inject the collaborator. I'd rather make the effort to use the framework consistently.

FTR, exposing the interface in the sample as you're doing does not hide the implementation in any way. If you ask the container for the implementation, it'll be able to inject it just fine. The best practices to return the most precise type is not related to AOT/Native, it's just that it becomes a problem there while the container is coping with the regular runtime.

Back to your question, I'd debug what GenericApplicationContext#preDetermineBeanTypes is doing. It's calling SmartInstantiationAwareBeanPostProcessor and that should ultimately create the proxy. If you know in advance a proxy is required, you could implement your own that does that explicitly.