Spring Boot JPA多对多的关系。得到意外响应

Question

我有两个实体用户和组，两个实体之间的关系是多对多。当我调用view-group/groupname时，我得到了group的用户列表。但是当我调用view-user/useremail时，我没有得到包含用户详细信息的组列表。

@Entity
@Table(name = "group_")
public class Group {

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

    @NotBlank
    private String groupName;

    @ManyToMany
    @JoinTable(name = "group_user", 
              joinColumns = { @JoinColumn(name = "group_id") }, 
              inverseJoinColumns = {@JoinColumn(name = "user_id") })
    public Set<User> usersOfgroup = new HashSet<>();

    public Group() {

    } 
}

@Entity
@Table(name="users")
public class User {
  
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    
    @NotBlank
    @Column(name="name")
    private String name;
    
    @NotBlank
    @Column(name="email")
    private String email;
            
    @JsonIgnore
    @ManyToMany(mappedBy = "usersOfgroup")
    public Set<Group> memberInGroups =new HashSet<>();
    
    public User() {
        
    }

{
    "id": 1,
    "groupName": "Group1",
    "usersOfgroup": [
        {
            "id": 2,
            "name": "Abhishek",
            "email": "[e-mail]",
        }
    ]
}

{
    "id": 2,
    "name": "Abhishek",
    "email": "[e-mail]",
}

{
    "id": 2,
    "name": "Abhishek",
    "email": "[e-mail]",
    "memberInGroups":[
          {
            "id": 1,
            "groupName": "Group1",
         }
       ]
}

Answer 1

您已经在public set memberInGroups=new hashset<>()上添加了 @jsonignore； ，这就是为什么json响应没有这方面的数据。删除注释，您将看到预期的响应

@jsonignore注释用于忽略序列化和反序列化中使用的逻辑属性。