Question

我正在使用Spring-Data-Neo4j创建示例。在此，执行CRUD操作，并且所有操作都成功运行。但是当我从实体获取关系集合时，它仅返回节点的graphId，其他值为空。以下是我的代码。如果我做错了，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;
}

控制器：

@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";
}

在控制器中，当我获取此人时，该人获取成功，但我获取了朋友，它包含start_node具有相同的人物对象，但end_node包含具有graphId的人物对象仅值，其他值为空。

Answer 1

要解决此问题，我们需要在@Fetch实体的起始节点和结束节点添加FriendsRelationship注释，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。

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

1 个答案: