java - Spring-Data-Neo4j:relationshipEntity 仅返回节点的 graphId。

Question

我正在使用 Spring-Data-Neo4j 创建一个示例。在此执行CRUD操作，所有操作运行成功。但是当我从实体获取关系船集合时，它仅返回节点的 graphId ，其他值为 null。以下是我的代码。如果我做错了什么，请纠正我。

实体:

@NodeEntity
@ToString(callSuper=true, exclude={"movies"})
@EqualsAndHashCode(callSuper = true, exclude = {"name", "movies"})
public class Person extends BaseEntity{

 @Getter @Setter
 @Indexed(unique = true)
 private Long id;
 @Getter @Setter
 private String name;
 @Getter @Setter
 @RelatedToVia(type = RelationshipTypes.FRIEND, elementClass = FriendsRelationship.class, direction = Direction.BOTH)
 private Set<FriendsRelationship> friends;
}

@RelationshipEntity(type=RelationshipTypes.FRIEND)
public class FriendsRelationship extends BaseEntity{

 @StartNode
 @Getter @Setter
 private Person person;
 @EndNode
 @Getter @Setter
 private Person friend;
 @Getter @Setter
 private String friendsType;
}

创建关系:

public FriendsRelationship createRelationshipBetweenPersons(Person person, Person friend, 
        Class<FriendsRelationship> relationshipEntity, String friendshipType) {
    FriendsRelationship relationship = neo4jTemplate.createRelationshipBetween(person, friend, relationshipEntity, friendshipType, true);
    neo4jTemplate.save(relationship);
    return relationship;
}

Controller :

@RequestMapping(value="find-person-by-id", method=RequestMethod.POST)
public String findPersonById(long id, Model model) {
    Person person =  personService.findPersonByProperty("id", id);
    model.addAttribute("actor", person);
    model.addAttribute("personFriends", person.getFriends());
    return "person/view-person-detail";
}

在 Controller 中，当我获取人员时，人员获取成功，但我获取 friend 时，它包含具有相同人员对象的 start_node ，但 end_node 仅包含具有 graphId 值的人员对象，其他值为 null。

Answer 1

为了解决这个问题，我们需要在 FriendsRelationship 实体的起始节点和结束节点添加 @Fetch 注解，如下所示:

@RelationshipEntity(type=RelationshipTypes.FRIEND)
public class FriendsRelationship extends BaseEntity{

 @Fetch @StartNode
 @Getter @Setter
 private Person person;
 @Fetch @EndNode
 @Getter @Setter
 private Person friend;
 @Getter @Setter
 private String friendsType;
}

现在数据获取成功了。