Creating a simple user/group model with permissions with Hibernate (annotations)

This is most likely a very basic question, but nevertheless:

Basically the User ent开发者_如何学JAVAity has an Id and a privilege enum. The group has an id and a name.

I wonder how to model a relationship where an user can be in multiple groups, having different privilege levels in different groups. Every group can of course have multiple members.

What's the way I'm supposed to solve that idiomatically with Hibernate? Adding some membership field to User? A membership field to Group? Both? Creating a new class for it? Which annotations are required to wire these things together?

I used next architecture

UserEntity class

@Entity
@Table(name = "user")
public class UserEntity implements Serializable {

    private Long user_id;
    private String username;
    private String password;

    public UserEntity() {

    }

    public UserEntity(String name, String passwd) {
        username = name;
        password = passwd;
    }

    @Column(name = "password", nullable = false)
    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    public Long getUser_id() {
        return user_id;
    }

    public void setUser_id(Long user_id) {
        this.user_id = user_id;
    }

    @Column(name = "username", nullable = false)
    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }
}

AuthorityEntity class

@Entity
@Table(name = "authority_role")
public class AuthorityEntity implements Serializable {

    private Integer id;
    private String authority;
    private List<UserEntity> people;

    public AuthorityEntity() {
    }

    public AuthorityEntity(String authString) {
        authority = authString;
    }

    @Column(name = "authority", nullable = false)
    public String getAuthority() {
        return authority;
    }

    public void setAuthority(String authority) {
        this.authority = authority;
    }

    @Id
    @Column(name = "id")
    @GeneratedValue(strategy = GenerationType.AUTO)
    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    @ManyToMany(targetEntity = UserEntity.class,
    cascade = {CascadeType.PERSIST, CascadeType.MERGE})
    @JoinTable(name = "authority_role_people",
    joinColumns =
    @JoinColumn(name = "authority_role_id"),
    inverseJoinColumns =
    @JoinColumn(name = "user_id"))
    public List<UserEntity> getPeople() {
        return people;
    }

    public void setPeople(List<UserEntity> people) {
        this.people = people;
    }
}

In fact - this is how implemented spring security plugin. In your case you can implement that architecture, which will be more useful for you.