How to hide "children": [] from last child in one to many relationship in spring boot

Question

Actually I want to use tree Json response for my react native application. So I build that in spring boot. But due to "children": [] in last child I face some issue in react native. So I want to hide that from my response.

1.I got this type of response

[{
            "id": 1,
            "name": "Martin",                
            "haveAccount": false,
            "gender": "m",
            "children": [
                {
                    "id": 4,
                    "name": "Werite",
                    "haveAccount": false,
                    "gender": "f",
                    "children": []
                }
                
            ]
        }]

2.But I don't want "children": [] in last child

example:-

    [{
                "id": 1,
                "name": "Martin",                
                "haveAccount": false,
                "gender": "m",
                "children": [
                    {
                        "id": 4,
                        "name": "Werite",
                        "haveAccount": false,
                        "gender": "f"
                    }
                    
                ]
            }]

3.Here is my Entity class

@Service
@Entity
@Table
public class Family {   
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY )
@Column(name="Family_id")
private Integer id;
private String name;
private String village;
private String wifeName;
private String talukaName;
private Boolean haveAccount;
private String username;
private String gender;
private String mobileNumber;




@OneToOne
@JoinColumn(name = "parent_id")
@JsonBackReference

private Family parent;

@OneToMany(mappedBy = "parent", cascade = CascadeType.ALL)
@JsonManagedReference
private List<Family> children = new ArrayList<>();


public Family(Integer id, String name, String village, String wifeName, String talukaName, Boolean haveAccount,
        String username, String gender, String mobileNumber, Family parent, List<Family> children) {
    super();
    this.id = id;
    this.name = name;
    this.village = village;
    this.wifeName = wifeName;
    this.talukaName = talukaName;
    this.haveAccount = haveAccount;
    this.username = username;
    this.gender = gender;
    this.mobileNumber = mobileNumber;
    this.parent = parent;
    this.children = children;
}
public Family() {
super();
    
}

public Integer getId() {
    return id;
}

public void setId(Integer id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public Family getParent() {
    return parent;
}

public void setParent(Family parent) {
    this.parent = parent;
}

public List<Family> getChildren() {
    return children;
}

public void setChildren(List<Family> children) {
    this.children = children;
}

public void addChild(Family children) {
    this.children.add(children);
}

public String getVillage() {
    return village;
}

public void setVillage(String village) {
    this.village = village;
}

public String getWifeName() {
    return wifeName;
}

public void setWifeName(String wifeName) {
    this.wifeName = wifeName;
}

public String getTalukaName() {
    return talukaName;
}

public void setTalukaName(String talukaName) {
    this.talukaName = talukaName;
}

public Boolean getHaveAccount() {
    return haveAccount;
}

public void setHaveAccount(Boolean haveAccount) {
    this.haveAccount = haveAccount;
}

public String getUsername() {
    return username;
}

public void setUsername(String username) {
    this.username = username;
}

public String getMobileNumber() {
    return mobileNumber;
}

public void setMobileNumber(String mobileNumber) {
    this.mobileNumber = mobileNumber;
}

public String getGender() {
    return gender;
}

public void setGender(String gender) {
    this.gender = gender;
}

}

Answer 1

If you want to delete a field you can put it a null and use @JsonInclude(Include.NON_NULL) on your class as follow:

@Service
@Entity
@Table
@JsonInclude(Include.NON_NULL)
public class Family {  
  //class
}

If you can handle that you should substitute private List<Family> children = new ArrayList<>(); with private List<Family> children; and initialize it when you are going to use it.

Just a question: Why are you using @Service on your entity class?