Avoid circular self references in hibernate entity

Question

I have a Hibernate entity with self references

@Entity
@Table(name = "category")
@NamedQuery(name = "Category.findAll", query = "SELECT c FROM Category c")
public class Category implements Serializable {

private static final long serialVersionUID = 1L;

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

@Column(nullable = false, length = 255)
private String name;

@Column(length = 255)
private String description;

@Column(nullable = false, length = 25, columnDefinition = "enum('Category','SubCategory','Indicator')")
private String type;

@ManyToMany
@JoinTable(name = "CategoryHierarchy", joinColumns = @JoinColumn(name = "parentId", referencedColumnName = "id"), inverseJoinColumns = @JoinColumn(name = "childId", referencedColumnName = "id"))
private List<Category> childs;

// getters and setters
}

So, obviously I was facing infinite recursion while deserializing the JSON when I was getting all the entities. So I added

@JsonIdentityInfo(generator = ObjectIdGenerators.IntSequenceGenerator.class, property = "@id")

above the class name. But now, the JSON only contains ids or numbers like

{
"success": true,
"messages": [
{
  "@id": 1,
  "id": 5,
  "name": "TestParentCategory ",
  "description": "This is test Parent category",
  "type": "Category",
  "status": "New",
  "childs": [
    {
      "@id": 2,
      "id": 6,
      "name": "TestChildCategory",
      "description": "This is test child category",
      "editTime": "2016-03-23T11:40:19",
      "editedBy": null,
      "createTime": "2016-03-23T11:40:19",
      "createdBy": 10,
      "type": "SubCategory",
      "status": "New",
      "childs": [
        {
          "@id": 3,
          "id": 8,
          "name": "TestChildCategory",
          "description": "This is test child category",
          "editTime": "2016-03-23T11:40:20",
          "editedBy": null,
          "createTime": "2016-03-23T11:40:20",
          "createdBy": 10,
          "type": "Indicator",
          "status": "New",
          "childs": [],
          "parents": [
            2,
            {
              "@id": 4,
              "id": 7,
              "name": "TestChildCategory",
              "description": "This is test child category",
              "editTime": "2016-03-23T11:40:19",
              "editedBy": null,
              "createTime": "2016-03-23T11:40:19",
              "createdBy": 10,
              "type": "SubCategory",
              "status": "New",
              "childs": [
                3,
                {
                  "@id": 5,
                  "id": 9,
                  "name": "TestChildCategory",
                  "description": "This is test child category",
                  "editTime": "2016-03-23T11:40:20",
                  "editedBy": null,
                  "createTime": "2016-03-23T11:40:20",
                  "createdBy": 10,
                  "type": "Indicator",
                  "status": "New",
                  "childs": [],
                  "parents": [
                    2,
                    4
                  ],
                  "opinions": [],
                  "timestamp": "2016-03-23T11:40:20",
                  "edited": "2016-03-23T11:40:20"
                }
              ]
            }
          ],
        },
      ]
    }
  ]
},
2,
4,
3,
5
]
}

I dont want numbers in the array (2, 4, 3, 5) but I want actual objects. How can I do that?

UPDATE I also went through the question so is it the only way to do it?

Avoid circular self references in hibernate entity

0 Answers0