JSON don't repeat some attributes and respective values

Question

for all instances serialized, from the second occurrence onwards, of the same model class, the objects only have a part of the attributes and their respective values ​​that they should. This way the JSON file structure is not homogeneous and uniform as expected by the old part of the application (Frontend).

[
{
    "id": 1,
    "fornecedor": {
        "cnpj": "80000876000177",
        "nome": "ATACADÃO DIA-A-DIA"
    },
    "itens": [
        {
            "id": 2,
            "produto": {
                "gtin": "7891991010856",
                "nome": "CERVEJA BUDWEISER"
            },
            "quantidade": 3,
            "preco": 3.5,
            "total": 10.5
        }
    ]
},
{
    "id": 3,
    "fornecedor": {
        "cnpj": "19600347000101",
        "nome": "SUPERMERCADO BELLA-VIA"
    },
    "itens": [
        {
            "id": 4,
            "produto": {
                "gtin": "7891991010857",
                "nome": "CERVEJA HEINEKEN"
            },
            "quantidade": 4,
            "preco": 5.4,
            "total": 21.6
        }
    ]
},
{
    "id": 5,
    "fornecedor": "19600347000101",
    "itens": [
        {
            "id": 6,
            "produto": "7891991010856",
            "quantidade": 4,
            "preco": 3.2,
            "total": 12.8
        }
    ]
},
{
    "id": 7,
    "fornecedor": "80000876000177",
    "itens": [
        {
            "id": 8,
            "produto": "7891991010857",
            "quantidade": 5,
            "preco": 4.9,
            "total": 24.5
        }
    ]
}
]

In the JSON above, the instances with id:1 and id:7 have a field named fornecedor that is structurally different and that shouldn't be because the Frontend expects them to be the same. Other samples are id:2 and id:6 with the field produto and so on.

The JSON above is the serialization of the list of model class Pedido below:

@Data
@Entity
@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "id") 
public class Pedido {

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@JsonView(View.External.class)
private Long id;

@ManyToOne
@JoinColumn(name = "fornecedor_cnpj")
@JsonView(View.External.class)
private Fornecedor fornecedor;

@OneToMany(mappedBy = "pedido", fetch = FetchType.LAZY,
        cascade = CascadeType.ALL)
@JsonView(View.External.class)
private List<Item> itens;

public List<Item> getItens() {
    if(itens == null){
        itens = new ArrayList<>();
    }
    return itens;
}
}

The model class Fornecedor is:

@Data
@Entity
@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "cnpj")
public class Fornecedor {

@Id
@JsonView(View.External.class)
private String cnpj;

@JsonView(View.External.class)
private String nome;

@OneToMany(mappedBy = "fornecedor", fetch = FetchType.LAZY,
        cascade = CascadeType.ALL)
@JsonView(View.Internal.class)
private List<Pedido> pedidos;

@OneToMany(mappedBy = "fornecedor", fetch = FetchType.LAZY,
        cascade = CascadeType.ALL)
@JsonView(View.Internal.class)
private List<Disponibilidade> disponilidades;
}

And the model class Produto is:

@Entity
@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class, property = "gtin")
@NoArgsConstructor
@Data
public class Produto {

@Id
@JsonView(View.External.class)
private String gtin;

@JsonView(View.External.class)
private String nome;

@OneToMany(mappedBy = "produto", fetch = FetchType.LAZY,
        cascade = CascadeType.ALL)
@JsonView(View.Internal.class)
private List<Disponibilidade> disponibilidades;

public Produto(String gtin) {
    this.gtin = gtin;
}
}

Question: The structure of JSON is the representation of expected behavior? If so, could someone tell me how do I make all instances from the first one to always have all attributes with their respective values ​​(as much as that means repeated attributes and values!).

Thanks!

Answer 1

The JSON you are getting is a consequence of the usage of @JsonIdentityInfo that you or someone else may have added to solve an infinite recursion while serializing your Java objects to JSON (you can read more about this at https://www.baeldung.com/jackson-bidirectional-relationships-and-infinite-recursion). This means that the only way to have the complete set of attributes in fornecedor and produto is to get rid of @JsonIdentityInfo on those classes. Keep in mind that this might create the infinite recursion problem mentioned above.

@Data
@Entity
public class Fornecedor {
    (...)
}

@Entity
@NoArgsConstructor
@Data
public class Produto {
    (...)
}