Question

我实现了一个存储库，一个实体和一个POJO，我想从存储库中调用findAll（）方法，但是即使填充了数据库，它也会返回空指针异常。问题在于，存储库为空，而不是执行选择后的列表。谁能帮我吗？

这是我的仓库：

 @Repository
 public interface UpcomingMatchesFactsRepository  extends 
 CrudRepository<UpcomingMatchesFacts, Integer> {

    public boolean existsByFirstPlayerName(String firstPlayerName);

    @Query(value = "" +
            "Select u " +
            "from UpcomingMatchesFacts u " +
            "order by abs(formula) desc ")
    List<UpcomingMatchesFacts> getHighestFormulaMatches();

    List<UpcomingMatchesFacts> findAll();
}

这是我的实体：

@Entity
@Table(name = "upcomingmatchesfacts")
public class UpcomingMatchesFacts {

    public UpcomingMatchesFacts(String firstPlayerName, String secondPlayerName, int matchesWonFirstPlayer,
                                int matchesWonSecondPlayer, int currentRankFirstPlayer, int currentRankSecondPlayer,
                                int ageFirstPlayer, int ageSecondPlayer, double formula) {
        this.firstPlayerName = firstPlayerName;
        this.secondPlayerName = secondPlayerName;
        this.matchesWonFirstPlayer = matchesWonFirstPlayer;
        this.matchesWonSecondPlayer = matchesWonSecondPlayer;
        this.currentRankFirstPlayer = currentRankFirstPlayer;
        this.currentRankSecondPlayer = currentRankSecondPlayer;
        this.ageFirstPlayer = ageFirstPlayer;
        this.ageSecondPlayer = ageSecondPlayer;
        this.formula = formula;
    }

这是我要使用该方法的类：

@EnableJpaRepositories
public class ChooseBestMatches {

    @Autowired
    private UpcomingMatchesFactsRepository upcomingMatchesFactsRepository;


    public void addBestMatchesToDatabase() {
        List<UpcomingMatchesFacts> upcomingMatchesFacts = Lists.newArrayList(upcomingMatchesFactsRepository.findAll());

                //upcomingMatchesFactsRepository.getHighestFormulaMatches().subList(0, 9);

        }
    }

Answer 1

如果您想将Spring bean注入其他类，它也必须是spring bean。在ChooseBestMatches类上使用@Service批注。

建议：@EnableJpaRepositories应该在Configuation类上，而不在服务上。实体必须具有noarg构造函数。

来自存储库的JPA方法findAll（）为空

1 个答案: