Hibernate и реализация таблицы "друзья"

@Entity
@Table(name = "users")
public class User {
 
    @Min(4)
    @Pattern(regexp = "[a-zA-Z0-9]+")
    @Column(name = "username", nullable = false, unique = true, length = 32)
    private String username;
 
    @Min(5)
    @Column(name = "password", nullable = false, length = 16)
    private String password;
 
    @Column(name = "email", nullable = false, unique = true)
    private String email;
 
    @Column(name = "authority", nullable = false)
    private String authority;
 
    @Column(name = "enabled", nullable = false)
    private boolean enabled = false;
 
    @Column(name = "friend_count",nullable = false)
    private int friend_count;
 
    @Column(name = "session", nullable = false)
    private boolean session = false;
 
}

@Entity
@Table(name = "friends")
public class Friends {
 
    @ManyToOne
    @JoinColumn(name = "username", foreignKey = @ForeignKey(name = "friend_one"))
    private String friend_one;
 
    @ManyToOne
    @JoinColumn(name = "username", foreignKey = @ForeignKey(name = "friend_two"))
    private String friend_two;
 
    @Enumerated(EnumType.STRING)
    @Column(name = "status", nullable = false)
    private FriendsStatusEnum status;
}

@Entity
@Table(name = "friends")
public class Friends {
 
    @ManyToOne
    @JoinColumn(name = "username", foreignKey = @ForeignKey(name = "friend_one"))
    private String friend_one;
 
    @ManyToOne
    @JoinColumn(name = "username", foreignKey = @ForeignKey(name = "friend_two"))
    private String friend_two;
 
    @Enumerated(EnumType.STRING)
    @Column(name = "status", nullable = false)
    private FriendsStatusEnum status;
}