Jackson 的 Stakover 流错误应用于 JPA 实体以生成 JSON

Question

我有一个 JPA 代码与 OneToMany 关系。 Customer 有一个 Item 的列表要签出。但是，代码继续生成 WhosebugError。

有一次，我通过在从 Customer 实体获取 List<Item> 时应用 @JsonIgnore 解决了这个问题。但即使这样似乎也不再有效了。

在Customer class:

@OneToMany(mappedBy = "customer", orphanRemoval = true)
@JsonIgnore
private List<Item> items;

在Item class:

@ManyToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "CUSTOMER_ID", nullable = false)
private Customer customer;

和CustomerRest class:

@Path("customers")
public class CustomerRest {

    @Inject
    NewSessionBean newSessionBean;

    @GET
    @Produces(MediaType.APPLICATION_JSON)
    public List<Customer> getAllCustomers() {
        return newSessionBean.getCustomers();
    }
}

方法newSessionBean.getCustomers():

public List<Customer> getCustomers(){
    TypedQuery<Customer> q= em.createQuery("select c from Customer c", Customer.class);

    return q.getResultList();
}

我希望收到格式良好的 JSON 消息，但没有任何迹象。我得到的只是浏览器上的 java.lang.WhosebugError 和服务器日志生成以下内容：

Generating incomplete JSON|#]
    java.lang.WhosebugError
    java.lang.WhosebugError    at org.eclipse.yasson.internal.serializer.DefaultSerializers.findByCondition(DefaultSerializers.java:130)

Answer 1

你好像用了Yasson project not Jackson. In that case you should use @JsonbTransient annotation. See documentation:

By default, JSONB ignores properties with a non public access. All public properties - either public fields or non public fields with public getters are serialized into JSON text.

Excluding properties can be done with a @JsonbTransient annotation. Class properties annotated with @JsonbTransient annotation are ignored by JSON Binding engine. The behavior is different depending on where @JsonbTransient annotation is placed.

另请参阅：

Jackson 的 Stakover 流错误应用于 JPA 实体以生成 JSON

Stakover flow error with Jackson applied on JPA Entities to generate JSON

java

json

one-to-many

jpa-2.0

yasson