How can I add additional columns to my joinTable in Spring?

Question

I currently have a User entity for my users and an Authority entity for my user "roles". This works well if my application only required users to have a specific authority to get tasks done, but that is not the case. Before I move on, here is the code for those entities:

User:

@Data
@Entity
@Table(name = "users")
public class User {

    @JsonIgnore
    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "user_seq")
    @SequenceGenerator(name = "user_seq", sequenceName = "user_seq", allocationSize = 1)
    private Long id;

    @Column(name = "username" unique = true)
    @NotNull
    @Size(min = 4, max = 50)
    private String username;

    @JsonIgnore
    @Column(name = "password")
    @NotNull
    private String password;

    @Column(name = "email", unique = true)
    @NotNull
    private String email;

    @JsonIgnore
    @Column(name = "activated")
    @NotNull
    private boolean activated;

    @ManyToMany
    @JoinTable(
        name = "user_authorities",
        joinColumns = {@JoinColumn(name = "user_id", referencedColumnName = "id")},
        inverseJoinColumns = {@JoinColumn(name = "authority_name", referencedColumnName = "name")}
    )
    private Set<Authority> authorities = new HashSet<>();

}

Authority:

@Data
@Entity
@Table(name = "authorities")
public class Authority {

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

}

Now, if I pull a user, I get something like this:

{
    username: "john",
    email: "john@doe.com",
    authorities: [
        {
            name: "ADMIN"
        }
    ]
}

Now, I am adding Company and Location entities into the mix. I would like a user to be able to have, let's say, ADMIN role for one Company , USER role for a certain Location , and a normal USER role. So for this said user, I would like something like this:

{
    username: "john",
    email: "john@doe.com",
    authorities: [
        {
            name: "ADMIN",
            companyId: 3
        },
        {
            name: "USER",
            locationId: 12
        },
        {
            name: "USER"
        }
    ]
}

I was thinking of just adding 2 NULLABLE columns to my joinTable , company_id and location_id , but I can't seem to add more than one join to the user_authorities table since it says that the table is already being joined with another entity. Is there a simple way to add this to my current setup or am I going about it the wrong way? Any enlightenment on this issue will be greatly appreciated. Thank you!

Answer 1

You can create other entity user_authorities and create two bidirecional @OneToMany associations.. Ex:

@Data
@Entity
@Table(name = "user_authorities")
public class UserAuthority {

   @JsonIgnore
   @Id
   @Column(name = "id")
   @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "user_authorities_seq")
   @SequenceGenerator(name = "user_authorities_seq", sequenceName = "user_authorities_seq", allocationSize = 1)
   private Long id;

   @ManyToOne
   @JoinColumn(name="user_id", nullable=false)
   private User user;

   @ManyToOne
   @JoinColumn(name="authority_id", nullable=false)
   private Authority authority;

   @NotNull
   private String otherField;

   @NotNull
   private String otherField2;

   //...

   public UserAuthority() {}

    // getters and setters

Answer 2

Replace the @ManyToMany association with two bidirectional @OneToMany associations, so create @Entity for user_authorities table.