Illegal reflective access operation warning for toString() on CGLIB proxies [SPR-17500]

[spring-projects-issues]

Matej Spiller-Muys opened SPR-17500 and commented

There are still some cases left that should be looked at. This WARNING is displayed when running application for a while.

WARNING: Illegal reflective access using Lookup on org.springframework.cglib.core.ReflectUtils (file:/Users/X/.m2/repository/org/springframework/spring-core/5.1.2.RELEASE/spring-core-5.1.2.RELEASE.jar) to class java.lang.Object
	at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:497)
	at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:359)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:106)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:104)
	at org.springframework.cglib.core.internal.LoadingCache$2.call(LoadingCache.java:54)
	at java.base/java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:264)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java)
	at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:61)
	at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:130)
	at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:315)
	at org.springframework.cglib.reflect.FastClass$Generator.create(FastClass.java:65)
	at org.springframework.cglib.proxy.MethodProxy.helper(MethodProxy.java:135)
	at org.springframework.cglib.proxy.MethodProxy.init(MethodProxy.java:76)
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:216)
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:684)
	at net.xxx.service.impl.ServiceImpl$$EnhancerBySpringCGLIB$$49f6ec4b.toString(<generated>)
	at net.xxx.MessageConsumer.onMessageHandler(MessageConsumer.java:216)
	at net.xxx.Consumer.onMessage(Consumer.java:144)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:1520)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.actualInvokeListener(AbstractMessageListenerContainer.java:1411)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:1387)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:1366)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:848)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:832)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$700(SimpleMessageListenerContainer.java:78)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1073)
	at java.base/java.lang.Thread.run(Thread.java:834)
WARNING: Illegal reflective access by org.springframework.cglib.core.ReflectUtils (file:/Users/X/.m2/repository/org/springframework/spring-core/5.1.2.RELEASE/spring-core-5.1.2.RELEASE.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
	at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:521)
	at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:359)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:106)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:104)
	at org.springframework.cglib.core.internal.LoadingCache$2.call(LoadingCache.java:54)
	at java.base/java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:264)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java)
	at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:61)
	at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34)
	at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:130)
	at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:315)
	at org.springframework.cglib.reflect.FastClass$Generator.create(FastClass.java:65)
	at org.springframework.cglib.proxy.MethodProxy.helper(MethodProxy.java:135)
	at org.springframework.cglib.proxy.MethodProxy.init(MethodProxy.java:76)
	at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:216)
	at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:684)
	at net.xxx.service.impl.ServiceImpl$$EnhancerBySpringCGLIB$$49f6ec4b.toString(<generated>)
	at net.xxx.MessageConsumer.onMessageHandler(MessageConsumer.java:216)
	at net.xxx.consumer.Consumer.onMessage(Consumer.java:144)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.doInvokeListener(AbstractMessageListenerContainer.java:1520)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.actualInvokeListener(AbstractMessageListenerContainer.java:1411)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.invokeListener(AbstractMessageListenerContainer.java:1387)
	at org.springframework.amqp.rabbit.listener.AbstractMessageListenerContainer.executeListener(AbstractMessageListenerContainer.java:1366)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.doReceiveAndExecute(SimpleMessageListenerContainer.java:848)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.receiveAndExecute(SimpleMessageListenerContainer.java:832)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer.access$700(SimpleMessageListenerContainer.java:78)
	at org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer$AsyncMessageProcessingConsumer.run(SimpleMessageListenerContainer.java:1073)
	at java.base/java.lang.Thread.run(Thread.java:834)

I am using Java 11.0.1 with Spring Boot 2.1.0.

---

Affects: 5.1.2

Issue Links:

• CglibAopProxy needs to detect package-visible methods when defined in a different ClassLoader [SPR-11618] #16241 CglibAopProxy needs to detect package-visible methods when defined in a different ClassLoader
• MethodHandles.Lookup.defineClass for CGLIB class definition purposes [SPR-15859] #20414 MethodHandles.Lookup.defineClass for CGLIB class definition purposes

Referenced from: commits 2a5d769

[spring-projects-issues]

Juergen Hoeller commented

Interestingly, both of those cases are triggered by toString() invocations, with CGLIB trying to create its fast-class adapter for java.lang.Object. We might have to explicitly bypass such attempts, using a regular reflective dispatch instead.

[spring-projects-issues]

Juergen Hoeller commented

It turns out that this is not easy to reproduce. Are there any specific constraints in your scenario, such as restricted visibility of your classes?

In general, we're bypassing straight invocations of java.lang.Object methods already. It might make a difference if you cast your instance to Object before calling toString() on it? Of course this is not a long-term solution, we need to make this work with subclass overrides as well...

[spring-projects-issues]

Juergen Hoeller commented

We're bypassing overridden equals / hashCode / toString methods now, performing straight reflective invocations to them (without CGLIB trying to create a fast class for them).

I couldn't actually reproduce the warning on JDK 11 but hopefully this defensive check makes it disappear in your scenario as well now.