java - JSON : There is a cycle in the hierarchy

Question

public class OrderEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Column(name="order_id")
    private int orderid;

    @ManyToOne
    @JoinColumn(name="user_id", nullable=false)
    private UserEntity user;

    @OneToMany(mappedBy="ordersBid",fetch=FetchType.EAGER)
    private Set<BidPriceEntity> bidOrders;
}
public class BidPriceEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    private int id;

    @ManyToOne
    @JoinColumn(name="order_Id",nullable=false)
    private OrderEntity ordersBid;

    @ManyToOne
    @JoinColumn(name="driver_Id",nullable=false)
    private UserEntity driver;      

    @Column(name="bid_price")
    private double bidPrice;
}
public class OrderEntity {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY) 
    @Column(name="order_id")
    private int orderid;

    @ManyToOne
    @JoinColumn(name="user_id", nullable=false)
    private UserEntity user;

    @OneToMany(mappedBy="ordersBid",fetch=FetchType.EAGER)
    private Set<BidPriceEntity> bidOrders;
}   

这是三个实体。我试图将数据(从数据库检索)传输到 JsonArray。它总是收到错误:层次结构中存在循环!

我应该如何设置:JsonConfig(setJsonPropertyFilter)属性来获取消除这个错误。

Answer 1

基本上有两个循环选项 - 编写自己的序列化器，使用@JsonIgnore。就像在您的代码中一样 - OrderEntity 包含 BidPriceEntities 列表，该列表又包含对 OrderEntity 的引用。用 @JsonIgnore 标记 ordersBid ，它应该可以工作。在列表序列化...如果您无权访问该类 - 尝试 mixins 。