Spring Data Rest-如何建立关联关系

Question

I have two classes, Role and Permission with a ManyToMany relationship between them. My problem is that each relationship has some extra data that comes with it therefore I believe I need to create an intermediary class to store these extra data, so that is the RolePermission class.

This is basically what I have, the parameter and domain are the extra data that are required for each relationship.

Here is the code I have right now for my classes.

Role.java

@Entity
@Table(name = "Sec_Role")
@DynamicUpdate
public class Role {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private String description;
    private String name;

    // This is another relationship which is working just fine (because there are no intermediary data needed.
    @ManyToMany(mappedBy = "roles", fetch = FetchType.EAGER) 
    private Set<Group> groups;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "role")
    private List<RolePermission> permissions = new ArrayList<RolePermission>(0);

    ...Standard getters and setters and constructor

Permission.java

@Entity
@Table(name = "Sec_Permission")
public class Permission {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private String name;

    @OneToMany(fetch = FetchType.LAZY, mappedBy = "permission")
    private List<RolePermission> roles = new ArrayList<RolePermission>(0);

    ...Standard getters and setters and constructor

RolePermission.java

@Entity
@Table(name = "Sec_Role_Permission")
@DynamicUpdate
public class RolePermission {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;
    private int domain;
    private String parameter;
    @Column(updatable = false, insertable = false)
    private int role_id;
    @Column(updatable = false, insertable = false)
    private int permission_id;

    @ManyToOne(fetch = FetchType.LAZY )
    @JoinColumn(name = "role_id", nullable = false)
    private Role role;

    @ManyToOne(fetch = FetchType.LAZY )
    @JoinColumn(name = "permission_id", nullable = false)
    private Permission permission;

    ...Standard getters and setters and constructor

Every class has a standard Repository like so

@RepositoryRestResource(path = "roles")
public interface RoleRepository extends CrudRepository<Role, Integer> {

}

Now this code works fine for reading data and relationships, my problem is that I cannot figure out what I am suppose to do or what end point to call to add/modify/delete a relationship between Role and Permission .

Currently if I call /roles/11/permissions I will get this back:

{
  "_embedded": {
    "rolePermissions": []
  },
  "_links": {
    "self": {
      "href": "http://localhost:8887/api/v1/roles/11/permissions"
    }
  }
}

How can I add a permission to this role?

I tried executing a POST request to /roles/11/permissions with the following JSON body and I got a 204 No Content response. This basically means success but then when I do a GET request to /roles/11/permissions I do not see permission with ID 1 there so it did not work.

{
  "domain": 0,
  "parameter": "Some param",
  "role_id": 11,
  "permission_id": 1
}

Answer 1

Since your mapping is itself an Entity you can model your API based on the Resource ( in this case RolePermission ). Basically when you would want to provide an API to add rolepermission

Some thing like

http://localhost:8887/api/v1/rolepermission

POST 

{
 "roleid":"xxxxx"
"permissionid":"xxxxxx"
"parameterid":"xxxxxx"
"domain":"xxxxx"

}