java - 使用关系将 JPA obect 反序列化为 JSON

Question

我有这个有关系的对象：

@Entity
@Table(name = "data_model")
public class DataModel {

    @Id
    @GeneratedValue
    @Column(name = "model_id")
    private Integer id;

    @Column(name = "name")
    private String name;

    @OneToMany(mappedBy = "dataModel", cascade = {CascadeType.PERSIST, CascadeType.REMOVE, CascadeType.MERGE})
    private List<OutputField> outputFields;
}

和：

@Entity
@Table(name = "data_model_output_field")
public class OutputField {

    @Id
    @GeneratedValue
    @Column(name = "output_field_id")
    private Integer id;

    @Column(name = "sourceTable")
    private String sourceTable;

    @JsonIgnore
    @ManyToOne(optional = false, fetch = FetchType.LAZY, cascade = CascadeType.REFRESH)
    @JoinColumn(name = "model_id")
    private DataModel dataModel;
}

我想将此 json 反序列化为 Java 对象：

{
  "name": "New data model with join",
  "outputFields": [
    {
      "sourceTable": "r"
    },
    {
      "sourceTable": "ri"
    }
  ]
}

当我尝试使用 Jackson 对其进行反序列化时，我明白了： 如何使用 Jackson 将父引用放入子元素中？

标签： javajsonjackson

Answer 1

我解决了。我使用JsonManagedReference和JsonBackReference注释：

@Entity
@Table(name = "data_model")
public class DataModel {

    @Id
    @GeneratedValue
    @Column(name = "model_id")
    private Integer id;

    @Column(name = "name")
    private String name;

    @JsonManagedReference(value = "outputFields")
    @OneToMany(mappedBy = "dataModel", cascade = {CascadeType.PERSIST, CascadeType.REMOVE, CascadeType.MERGE})
    private List<OutputField> outputFields;
}

@Entity
@Table(name = "data_model_output_field")
public class OutputField {

    @Id
    @GeneratedValue
    @Column(name = "output_field_id")
    private Integer id;

    @Column(name = "sourceTable")
    private String sourceTable;

    @JsonBackReference(value = "outputFields")
    @ManyToOne(optional = false, fetch = FetchType.LAZY, cascade = CascadeType.REFRESH)
    @JoinColumn(name = "model_id")
    private DataModel dataModel;
}