Neo4j: Error for relationship property: Property values can only be of primitive types or arrays thereof

问题

According to https://docs.spring.io/spring-data/neo4j/docs/4.0.0.M1/reference/html/#__relationship_connecting_node_entities I want to save nodes that have a 1:1 relation to another complex node. Used Neo4j version: 3.2.6

Following use case:

For uploaded files specific information about these files are stored into Neo4j as an entity of FileHashEntity
Users who are uploading files are present as user objects in Neo4j: BaseUserEntity and UserEntity
FileHashEntity has a relationship to the user who originally uploaded the file the first time

The Java classes that specify the user objects are declared as following:

@NodeEntity
public abstract class BaseUserEntity {

    @GeneratedValue
    @Id
    private Long id;
...
}

public class UserEntity extends BaseUserEntity {

    @Id
    private String email;

    private String passwordHash;
...
}

And the entity for the file information looks like this:

@NodeEntity
public class FileHashEntity {
    @DateLong
    private Date creationTime;

    @Id
    private String sha256;

...

    private long size;

    @Relationship(type = "UPLOADED_BY", direction = Relationship.OUTGOING)
    private UserEntity uploader;
...
}

If I try to store the FileHashEntity I receive an error due to the complex object property (UserEntity):

public interface FileHashRepository extends Neo4jRepository<FileHashEntity, String> {

    @Query(value = "merge (n:FileHashEntity {sha256: {0}}) on create set n = {1} return n")
    FileHashEntity storeIfNotExists(String sha256, FileHashEntity entity);
...
}

Caused by: org.neo4j.driver.v1.exceptions.ClientException: Property values can only be of primitive types or arrays thereof
    at org.neo4j.driver.internal.net.SocketResponseHandler.handleFailureMessage(SocketResponseHandler.java:76)

But the Spring documentation states that this should be possible even without explicit @Relationship annotation (see link above). I even tried to replace the declaration type UserEntity by BaseUserEntity. What's wrong?

来源：https://stackoverflow.com/questions/50665958/neo4j-error-for-relationship-property-property-values-can-only-be-of-primitive

标签

java

Spring

neo4j