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外键对POST的结果不起作用,但是GET起作用

spring-data-rest spring-data-jpa hibernate spring java

Snæbjørn · 技术社区 · 8 年前

这个 orderTypeId Order 在创建的响应中丢失,但随后的GET请求产生预期结果。

下面是一个我想要实现的小例子。

POST /api/orders
{
    "orderType": "orderTypes/1",
}

或 GET /api/orders/2

输出

{
    "id": 2,
    "orderTypeId": 1,            // either this
    "orderType": "orderTypes/1"  // or this
    "_links": {
        "self": {
            "href": "http://localhost:8090/api/orders/2"
        },
        "order": {
            "href": "http://localhost:8090/api/orders/2"
        },
        "orderType": {
            "href": "http://localhost:8090/api/orders/2/orderType"
        },
        "orderType": {
            "href": "orderTypes/1" // this could even be acceptable
        }
    }
}

@Data
@Entity
public class Order {
  @Id
  @GeneratedValue
  private Long id;

  @Column(name = "order_type_id", nullable = false, insertable = false, updatable = false)
  private Long orderTypeId;

  @NotNull
  @ManyToOne
  @JoinColumn(name = "order_type_id")
  private OrderType orderType;
}

@Data
@Entity
public class OrderType {
  @Id
  @GeneratedValue
  private Long id;

  @Column(nullable = false)
  private String name;

  @JsonIgnore
  @OneToMany(mappedBy = "orderType")
  private List<Order> orders;
}

控制器

@RepositoryRestResource
public interface OrderRepository extends JpaRepository<Order, Long> {}

岗位

{
}

输出

{
    "id": 2,
    "orderTypeId": null,
    "_links": {
        "self": {
            "href": "http://localhost:8090/api/orders/2"
        },
        "order": {
            "href": "http://localhost:8090/api/orders/2"
        },
        "orderType": {
            "href": "http://localhost:8090/api/orders/2/orderType"
        }
    }
}

GET /orders/2

我做错什么了?

我试过别的

@Data
@Entity
public class Order {
  @Id
  @GeneratedValue
  private Long id;

  @NotNull
  @ManyToOne
  @JoinColumn
  @JsonManagedReference
  @RestResource(exported=false) // ADDED
  private OrderType orderType;
}

@Data
@Entity
public class OrderType {
  @Id
  @GeneratedValue
  private Long id;

  @Column(nullable = false)
  private String name;

  // removed orders
}

获取/api/orders/2

{
    "id": 2,
    "orderTypeId": {
        "id": 1,
        "name": "foo"
    },
    "_links": {
        "self": {
            "href": "http://localhost:8090/api/orders/2"
        },
        "order": {
            "href": "http://localhost:8090/api/orders/2"
        }
    }
}

但现在POST不起作用:(

{
“orderType”:“orderTypes/1”,

返回400个错误请求。。。

2 回复 | 直到 8 年前

abstractKarshit 8 年前

使用 @JsonIgnore 不是推荐的方法,要管理循环依赖关系请使用 @JsonManagedReference 实体:

@Data
@Entity
public class Order {
    @Id
    @GeneratedValue
    private Long id;

   @Column(name = "order_type_id", nullable = false, insertable = false, updatable = false)
   private Long orderTypeId;

   @JsonBackReference(value="name")
   @ManyToOne
   @JoinColumn(name = "order_type_id")
   private OrderType orderType;
}


@Data
@Entity
public class OrderType {
   @Id
   @GeneratedValue
   private Long id;

   @Column(nullable = false)
   private String name;

   @JsonManagedReference(value = "name")
   @OneToMany(mappedBy = "orderType")
   private List<Order> orders;
}

您可以稍后执行GET调用,因为在您的案例中已经发生了,也可以在保存后在POST api中使用rest控制器。您可以在返回之前按id执行GET调用,或者使用DTO发送响应。

Alan Hay 8 年前

我不太清楚为什么需要将此映射为持久字段。简单地添加getter应该意味着它包含在任何JSON响应中:

@Data
@Entity
public class Order {
  @Id
  @GeneratedValue
  private Long id;

  @NotNull
  @ManyToOne
  @JoinColumn(name = "order_type_id")
  private OrderType orderType;

  public Long getOrderTypeId(){
    return orderType != null ? orderType.getId() : null;
  }
}

如果失败,则可以为 AfterCreateEvent

https://docs.spring.io/spring-data/rest/docs/current/reference/html/#events

或者根据关联的 OrderType EntityManager

https://docs.oracle.com/javaee/6/api/javax/persistence/EntityManager.html#refresh(java.lang.Object)

@RepositoryEventHandler 
public class OrderEventHandler {

@PersistenceContext
private EntityManager em;

  @HandleAfterCreate
  public void onOrderCreated(Order o) {
    em.refresh(o);
  }
}