如何隐藏“孩子”：[]从弹簧靴中一对多关系中的最后一个孩子

Question

实际上我想为我的反应原生应用程序使用树 Json 响应。所以我在spring boot中构建它。但是由于 "children": [] in last child 我在反应原生时遇到了一些问题。所以我想在我的回复中隐藏它。

1.我收到了这样的回复

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

2.但我不想要 "children": [] in last child

例子：-

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

3.这是我的实体类

@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

如果你想删除一个字段，你可以把它设为 null 并在你的类上使用@JsonInclude(Include.NON_NULL)，如下所示：

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

如果您可以处理，您应该将private List<Family> children = new ArrayList<>(); 替换为private List<Family> children;，并在您打算使用它时对其进行初始化。

只是一个问题：你为什么在你的实体类上使用@Service？