Question

我有以下Cypher查询。它返回一个球员列表和每个球员所有联赛的列表。现在对于每个返回的玩家，我想创建Person NodeEntity，而不是使用NodeProxy。想知道这样做的有效方法是什么。

String q = "START t=node({teamId}) MATCH player-[:PLAYED_WITH_TEAM]->t-[:CONTESTED_IN]->league WITH player AS player, league.startDate AS startDate, league.name AS leagueName ORDER BY startDate RETURN player,  collect(leagueName) AS leagueNames";

Map<String, Object> params = Maps.newHashMap();
params.put("teamId", selectedTeam);

Result<Map<String, Object>> result = template.query(q, params);

final List<Player> players = new ArrayList<Player>();

result.handle(new Handler<Map<String, Object>>()
{
    @Override
    public void handle(Map<String, Object> value)
    {       
        players.add((Player) value.get("player"));
    }
});

异常

SEVERE: Servlet.service() for servlet [appServlet] in context with path [/avl] threw exception [Request processing failed; nested exception is java.lang.ClassCastException: org.neo4j.kernel.impl.core.NodeProxy cannot be cast to com.aravind.avl.domain.Player] with root cause
java.lang.ClassCastException: org.neo4j.kernel.impl.core.NodeProxy cannot be cast to com.aravind.avl.domain.Player
    at com.aravind.avl.controller.RegistrationController$1.handle(RegistrationController.java:103)

Answer 1

您应该使用 Neo4jOperations 界面中的 convert 方法将返回的对象转换为适当的类;这是一个例子：

neo4jOperations.convert(value.get("player"), Player.class);

neo4jOperations 对象由Spring Data Neo4j基础结构使用 @Autowired 注释注入。

在spring-data-neo4j中将NodeProxy转换为NodeEntity

1 个答案: