Neo4j-OGM关系未加载

Question

In my project I have MapNodes , which are connected by a relation ConnectRelation . ConenctRelation has a property length. Nodes and their relations are saved to the Neo4J database without problems. But when loading the Nodes, the relationsList is empty.

---

MapNode class

@NodeEntity
public abstract class MapNode extends Circle implements IObservable{

@GraphId
Long id;

@Relationship(type = "CONNECTS_TO")
private ArrayList<ConnectRelation> relations = new ArrayList<>();

@Property(name="x")
private double xCoordinate;

@Property(name="y")
private double yCoordinate;

public ConnectRelation connectToNode(MapNode otherNode){
    ConnectRelation relation = new ConnectRelation(this,otherNode);
    relation.setLength(2);
    this.relations.add(relation);
    return relation;
}
.
.

---

ConnectRelation class:

@RelationshipEntity
public class ConnectRelation extends Line implements IObserver {

@GraphId
Long id;

@StartNode
MapNode startNode;

@EndNode
MapNode endNode;

@Property(name="startX")
private double startXCoordinate;
@Property(name="startY")
private double startYCoordinate;

@Property(name="endX")
private double endXCoordinate;
@Property(name="endY")
private double endYCoordindate;

@Property(name="length")
private double length;
.
.

---

Fill and load methods:

 public static void fillDb(){
    getSession().purgeDatabase();

    Room roomOne = new Room();
    roomOne.setXCoordinate(100);
    roomOne.setYCoordinate(100);
    Room roomTwo = new Room();
    roomTwo.setXCoordinate(200);
    roomTwo.setYCoordinate(200);

    ConnectRelation connectRelation = roomOne.connectToNode(roomTwo);

    getSession().save(roomOne);
    getSession().save(roomTwo);
    getSession().save(connectRelation);
}

public void loadNodes(){
    mapNodeList = new ArrayList<>(DatabaseRepository.getSession().loadAll(MapNode.class,2));
    mapNodeList.forEach(n -> {
        n.getRelations().forEach(r -> {
            if(!relationList.contains(r)){
                relationList.add(r);
            }
        });
    });
}

The problem I have is that the relations field in MapNode is empty when loading the nodes, even when the depth is set to something larger than 1.

Thanks in Advance!

Answer 1

The only obvious thing I can see is the relationship type not being defined on the @RelationshipEntity -

@RelationshipEntity(type = "CONNECTS_TO")
public class ConnectRelation...

That could be it- please add it and if the relationships are still not loaded, could you turn debug on and share anything of interest? Add

<logger name="org.neo4j.ogm" level="debug" />

to logback.xml