PropertyReferenceException if path expression maps into simple type properties

[murdos]

While working on the SpringBoot 2.3 support in JHipster, I stumble upon an new issue that we had not before:

org.springframework.data.mapping.MappingException: Couldn't find PersistentEntity for type java.lang.String!

	at org.springframework.data.mapping.context.MappingContext.getRequiredPersistentEntity(MappingContext.java:119)
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.getPair(PersistentPropertyPathFactory.java:237)
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.createPersistentPropertyPath(PersistentPropertyPathFactory.java:210)
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.lambda$getPersistentPropertyPath$2(PersistentPropertyPathFactory.java:183)
	at java.base/java.util.concurrent.ConcurrentMap.computeIfAbsent(ConcurrentMap.java:330)
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.getPersistentPropertyPath(PersistentPropertyPathFactory.java:182)
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.from(PersistentPropertyPathFactory.java:97)
	at org.springframework.data.mapping.context.PersistentPropertyPathFactory.from(PersistentPropertyPathFactory.java:110)
	at org.springframework.data.mapping.context.AbstractMappingContext.getPersistentPropertyPath(AbstractMappingContext.java:286)

I've created a minimal project to expose the issue: https://github.com/murdos/spring-data-r2dbc-mapping-bug

The issues seems to comes from the password_hash column of the jhi_user table: because propertyPath is then valued to User.password.hash.
It the column is renamed to passwordhash everything works fine.

[mp911de]

Thanks for reporting the issue. Spring Data's PropertyPath resolution tries to introspect the property password assuming that hash is a nested property of password. Therefore it attempts to introspect String which isn't an entity and so the mapping fails.

This issue pops up also in other Spring Data modules so we probably need to take a deeper look how to handle the issue.

[mp911de]

That's fixed now.