Question

我是Spring编程的新手，在下面的例子中尝试了BID和BIDITEM类之间的一对多关系。我不确定是否保存了BIDITEM数据，因为当我尝试检索BID时，我只获得BID数据而不是BIDITEM数据。我们是否需要为BIDITEM类设置存储库。我可以看到在create方法中接收到完整的BID JSON字符串以及BIDITEM。你能不能通过它，让我知道它有什么问题。

@Entity
@Table(name = "bid")
public class Bid {
    @Id
    private String title;
    @Column
    private long startDate;
    @Column
    private long endDate;
    @OneToMany(mappedBy = "myBid", cascade = {CascadeType.ALL})
    private List<BidItem> bidItems = new ArrayList<BidItem>();
//Constructor, getter and setter methods go here    
}   

@Entity
@Table(name="biditem")
public class BidItem 
{
    @Id
    private String item;
    @Column
    private String desc;
    @Column
    private double minAmt;
    @ManyToOne
    @JoinColumn(name = "title")
    private Bid myBid;  
//Constructor, getter and setter methods go here
}   

public interface BidRepository extends CrudRepository<Bid, String> {
//Tried even JpaRepository

}

public class BidService {
    ObjectMapper mapper = new ObjectMapper();
    @Autowired
    private BidRepository bidRepo;

    public Bid create(String bidJson) throws JsonParseException, JsonMappingException, IOException
    {
        Bid bid = mapper.readValue(bidJson, Bid.class);     

//   bidJson string has below string 
//   {"bidItems":[{"item":"item1","desc":"item1","minAmt":"999"}],
//    "title":"bid1","startDate":"D1","endDate":"D5"}

        Bid savedBid = bidRepo.save(bid);
        return savedBid;
    }
    public Bid findByID(String title)
    {
        Bid bid = bidRepo.findOne(title);
        return bid;
    }
}

如何编写Spring JPA onetomany关系

0 个答案: