关系未保存在 SDN 6（Spring 数据 neo4j）中

Question

Hello have problems with saving relation ships with NEO4J and Spring, I can save relationships when I don't use a class with @RelationProperties , but whenever I want to use that class the relationships are not even created.

I am using Neo4j 4.3.7-community edition in a docker container And in my pom.xml i have

        <dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-neo4j</artifactId>
            <version>6.1.5</version>
        </dependency>

I want to do something like this Image

I have this bit of code:

starting node

...
    @Relationship(type = "VISITS",direction = Relationship.Direction.OUTGOING)
    public Set<Visits> visits;

    public void visitPOI(Visits visit) {
        if(visits == null) {
            visits = new HashSet<>();
        }
        visits.add(visit);
    }
...

My relation

@RelationshipProperties
public class Visits {
    @Id @GeneratedValue
    private long id;

    @Property private String description;

    @TargetNode private PointOfInterest poi;

    public Visits(String description, PointOfInterest p){
        this.description = description;
        this.poi = p;
    }
...

and the destination node

...
@Node
public class PointOfInterest {

    @Id @GeneratedValue(generatorClass = UUIDStringGenerator.class)
    private String id;



    @Property private String name;
    @Property private double lat;
    @Property private double lng;

    public PointOfInterest() { }

//getters and setters
...

And this in a service

...
    public void saveRelation(String username, Visits v ){

        User u = userRepository.findByUserName(username);

        Optional<PointOfInterest> poi = pointOfInterestRepository.findById(v.getPoi().getId());
        v.setPoi(poi.get());
        u.visitPOI(v);
        userRepository.save(u);
    }
...

and the JSON I post

{
    "description":"Nice trip",
    "poi":{
        "id":"Uster"
    }
}

Answer 1

Use @RelationshipId on id field of @RelationshipProperties as follow

@RelationshipProperties
public class Visits {
    @RelationshipId
    private long id;

    @Property private String description;
    .....
}

Answer 2

I had the same issue with persisting relationship properties using @RelationshipProperty annotated class. Finally, I discovered that the issue is due to the implicit conversion between long and Long. Changing @RelationshipId private long id; to @RelationshipId private Long id; inside the @RelationshipProperty annotated class will do the trick. This appears to be a bug in SDN, it should report an error instead.