Spring Kotlin + JDK 12: Illegal reflective access by org.springframework.util.ReflectionUtils to java.lang.Enum

Affects: Spring Framework 5.1.5 Language used: Kotlin Other Dependencies: Web, Neo4j The error can be reproduced using the following code:

import org.neo4j.ogm.annotation.NodeEntity

enum class Rank {
    ACE, TWO, THREE, FOUR, FIVE, SIC, SEVEN, EIGHT, NINE, TEN
}

enum class Suit {
    SPADES, CLUBS, DIAMONDS, HEARTS
}

@NodeEntity
data class Card(val rank: Rank = Rank.ACE, val suit: Suit = Suit.SPADES)

The error message (with --illegal-access=debug) is as follows:

WARNING: Illegal reflective access by org.springframework.util.ReflectionUtils (file:/home/khokho/.m2/repository/org/springframework/spring-core/5.1.5.RELEASE/spring-core-5.1.5.RELEASE.jar) to field java.lang.Enum.name
    at org.springframework.util.ReflectionUtils.makeAccessible(ReflectionUtils.java:483)
    at org.springframework.data.mapping.context.AbstractMappingContext$PersistentPropertyCreator.doWith(AbstractMappingContext.java:509)
    at org.springframework.util.ReflectionUtils.doWithFields(ReflectionUtils.java:756)
    at org.springframework.data.mapping.context.AbstractMappingContext.addPersistentEntity(AbstractMappingContext.java:383)
    at org.springframework.data.mapping.context.AbstractMappingContext.addPersistentEntity(AbstractMappingContext.java:332)
    at org.springframework.data.neo4j.mapping.Neo4jMappingContext.lambda$new$1(Neo4jMappingContext.java:65)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
    at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
    at java.base/java.util.HashMap$ValueSpliterator.forEachRemaining(HashMap.java:1672)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
    at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
    at org.springframework.data.neo4j.mapping.Neo4jMappingContext.<init>(Neo4jMappingContext.java:65)
    at org.springframework.data.neo4j.repository.config.Neo4jMappingContextFactoryBean.createInstance(Neo4jMappingContextFactoryBean.java:93)
    at org.springframework.data.neo4j.repository.config.Neo4jMappingContextFactoryBean.createInstance(Neo4jMappingContextFactoryBean.java:35)
    at org.springframework.beans.factory.config.AbstractFactoryBean.afterPropertiesSet(AbstractFactoryBean.java:142)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1821)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1758)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:830)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
WARNING: Illegal reflective access by org.springframework.util.ReflectionUtils (file:/home/khokho/.m2/repository/org/springframework/spring-core/5.1.5.RELEASE/spring-core-5.1.5.RELEASE.jar) to field java.lang.Enum.ordinal
    at org.springframework.util.ReflectionUtils.makeAccessible(ReflectionUtils.java:483)
    at org.springframework.data.mapping.context.AbstractMappingContext$PersistentPropertyCreator.doWith(AbstractMappingContext.java:509)
    at org.springframework.util.ReflectionUtils.doWithFields(ReflectionUtils.java:756)
    at org.springframework.data.mapping.context.AbstractMappingContext.addPersistentEntity(AbstractMappingContext.java:383)
    at org.springframework.data.mapping.context.AbstractMappingContext.addPersistentEntity(AbstractMappingContext.java:332)
    at org.springframework.data.neo4j.mapping.Neo4jMappingContext.lambda$new$1(Neo4jMappingContext.java:65)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183)
    at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:177)
    at java.base/java.util.HashMap$ValueSpliterator.forEachRemaining(HashMap.java:1672)
    at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
    at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
    at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150)
    at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173)
    at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
    at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:497)
    at org.springframework.data.neo4j.mapping.Neo4jMappingContext.<init>(Neo4jMappingContext.java:65)
    at org.springframework.data.neo4j.repository.config.Neo4jMappingContextFactoryBean.createInstance(Neo4jMappingContextFactoryBean.java:93)
    at org.springframework.data.neo4j.repository.config.Neo4jMappingContextFactoryBean.createInstance(Neo4jMappingContextFactoryBean.java:35)
    at org.springframework.beans.factory.config.AbstractFactoryBean.afterPropertiesSet(AbstractFactoryBean.java:142)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1821)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1758)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:593)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:830)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)

I don't really know if the bug is from Spring Framework's ReflectionUtils or Spring Data Neo4j

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Comment From: jhoeller

ReflectionUtils is just a tool being used here, doing what the AbstractMappingContext instructs it to do. So this really needs to be addressed on Spring Data's end.

Comment From: lachance-martin

Does anyone know if this has been addressed on Spring Data's end? I am not able to find the related issue, and the problem still exists with Spring Data Neo4j 5.2.0.

Comment From: schauder

I created https://jira.spring.io/browse/DATAGRAPH-1258 in order to get this fixed.

Comment From: sdeleuze

@schauder Thanks!

Comment From: GrahamLea

See also https://jira.spring.io/browse/DATAGRAPH-1321, might be related.