ClassTypeInformation: issue with enhanced classes

[dellermann]

After upgrade to Spring Boot 2.6 loading objects from MongoDB using DBRef(lazy = true) doesn't work any more. AbstractMappingContext.hasPersistentEntityFor() doesn't find find enhanced classes such as FooBar$$EnhancerByCGLIB$$. It is caused by commit c866b42 which changes src/main/java/org/springframework/data/util/ClassTypeInformation.java line 94 from

super(ProxyUtils.getUserClass(type), getTypeVariableMap(type));

to

super(type, getTypeVariableMap(type));

Thus, enhanced classes will not be found in map AbstractMappingContext.persistentEntities.

[mp911de]

Can you provide a bit more context here, for instance some sample code that fails for you?

[dellermann]

I have two domain model classes, e. g.

import java.math.BigDecimal;
import lombok.Data;
import org.springframework.data.mongodb.core.mapping.DBRef;
import org.springframework.data.mongodb.core.mapping.Document;

@Data
@Document
public class Price {
    @DBRef(lazy = true) private VatRate vatRate;
}

@Data
@Document
public class VatRate {
    private String name;
    private BigDecimal value;
}

and a MongoDB repository:

import org.springframework.data.rest.core.annotation.RepositoryRestResource;
import org.springframework.data.mongodb.repository.MongoRepository;

@RepositoryRestResource
public interface PriceRepository extends MongoRepository<Price, String>
{
}

When I obtain Price objects via REST using GET /prices I get the following exception:

:
:
org.springframework.data.mapping.MappingException: Cannot get or create PersistentEntity for type foo.bar.VatRate$$EnhancerByCGLIB$$8791e8ac! PersistentEntities knows about 2 MappingContext instances and therefore cannot identify a single responsible one. Please configure the initialEntitySet through an entity scan using the base package in your configuration to pre initialize contexts.
	org.springframework.data.mapping.context.PersistentEntities.lambda$getRequiredPersistentEntity$0(PersistentEntities.java:119)
	java.base/java.util.Optional.orElseThrow(Optional.java:401)
	org.springframework.data.mapping.context.PersistentEntities.getRequiredPersistentEntity(PersistentEntities.java:118)
	org.springframework.data.rest.core.support.DefaultSelfLinkProvider.entityIdentifierOrNull(DefaultSelfLinkProvider.java:120)
	org.springframework.data.rest.core.support.DefaultSelfLinkProvider.getResourceId(DefaultSelfLinkProvider.java:109)
	org.springframework.data.rest.core.support.DefaultSelfLinkProvider.createSelfLinkFor(DefaultSelfLinkProvider.java:84)
	org.springframework.data.rest.webmvc.mapping.DefaultLinkCollector$NestedLinkCollectingAssociationHandler.lambda$doWithAssociation$0(DefaultLinkCollector.java:234)
	java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
	java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
	java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
	java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
	java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:913)
	java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
	java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:578)
	org.springframework.hateoas.Links.andIf(Links.java:187)
	org.springframework.hateoas.Links.andIf(Links.java:165)
:
:

When looking in org.springframework.data.mapping.context.PersistentEntities.getRequiredPersistentEntity it calls getPersistentEntity and this in turn hasPersistentEntityFor. The implementation org.springframework.data.mapping.context.AbstractMappingContext.hasPersistentEntityFor calls this line:

Optional<E> entity = persistentEntities.get(ClassTypeInformation.from(type));