Composite object not showing up in the response – Spring Boot



So I’m getting some roles introduced in my system. I have a class that looks like this :

@Entity
@Table(name = "user_role_mapping")
@AllArgsConstructor
@NoArgsConstructor
@Data
public class UserRoleMapping {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id")
    Integer id;

    @Column(name = "role_id")
    Role role;

    @ManyToOne
    @JoinColumn(name = "user_id")
    User user;

    public UserRoleMapping(Role role, User user) {
        this.role = role;
        this.user = user;
    }
}

The classes that are mapping by this look like as follows :

public enum Role {
    ROLE_CUSTOMER(1) , ROLE_ADMIN(0);

    public int id;

    private Role (int id){
    }
}

The user class looks like :

public class User {

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

    @Column(name = "phone")
    private String phoneNumber;

    @Column(name = "name")
    private String name;

    @OneToMany(mappedBy = "id", fetch = FetchType.EAGER,
            cascade = CascadeType.ALL)
    private Set<UserRoleMapping> userRoles;
}

For an initial POC , i wrote a simple API method that looks like :

@RequestMapping(value = "", method = RequestMethod.GET)
        public ResponseEntity<?> returnUserAndDefaultRole( @RequestParam(name = "phone") String phone) {
           User user = usersRepository.findByPhoneNumber(phone);
           List<UserRoleMapping> urm = userRoleMappingRepository.findAllByUser(user);
        UserRoleMapping userRoleMapping;
        if (urm.size() == 0) {
            userRoleMapping = new UserRoleMapping(Role.ROLE_CUSTOMER, user);
            userRoleMappingRepository.save(userRoleMapping); }
        else {
            userRoleMapping  = urm.get(0);
        }
        Map<String, Object> result = new HashMap<>();
        result.put("User", user );
        result.put("Role_info" ,userRoleMapping);
        return new ResponseEntity<>(result, HttpStatus.OK);
    }

Here, I expect to get the User object which also has a Set as well as one userRoleMapping object under the Role_info key.

My actual output looks like :

    "User": {
        "id": 1542275,
        "phoneNumber": "9527725710",
        "name": "njari",
       
        "userRoles": []
    },
    "Role_info": {
        "id": 1,
        "role": "ROLE_CUSTOMER",
        "user": {
            "id": 1542275,
             "phoneNumber": "9527725710",
            "name": "njari",
            "userRoles": []
        }
    }
}

My Role_Info is populated. However, The userRoles within the user object isn’t. First, I want the inner Set of userRoles to be populated. Second,I also don’t want the Role_Info to include the entire User object, how do I achieve this?

Answer

  1. If i am not wrong, please try changing your mapping

     @OneToMany(mappedBy = "id", fetch = FetchType.EAGER,
                     cascade = CascadeType.ALL)
     private Set<UserRoleMapping> userRoles;
    

To:

@OneToMany(mappedBy = "user", fetch = FetchType.EAGER,
            cascade = CascadeType.ALL)
    private Set<UserRoleMapping> userRoles;
  1. To exclude the field/object, i am using @JsonIgnore:

     @JsonIgnore
     @ManyToOne
     @JoinColumn(name = "user_id")
     User user;
    


Source: stackoverflow