映射和查询此实体的最佳方法

Question

I have three entities User, Center and Profile, so a user has different profiles depending on the center he's in. So we have a table which links the three entities called *user_center_profile*.

Then we have another entity, called Permission which is linked to Profile, so a profile has several permissions.

Because the main entity is User, I have it maped like this:

        @Entity
        @Table(name = "profile")
        public class Profile implements Serializable {

            @Id
            @GeneratedValue(strategy = GenerationType.AUTO)
            @Column(name = "idprofile")
            private Long idProfile;
            @Column(name = "codprofile")
            private String codProfile;
            @Column(name = "desprofile")
            private String desProfile;
            @OneToMany
            @JoinTable(name = "profile_permission", joinColumns = { @JoinColumn(name = "idProfile") }, inverseJoinColumns = { @JoinColumn(name = "idPermission") })
            private List<Permission> permissions = new ArrayList<Permission>();

            /* getters and setters */
        }

        @Entity
        @IdClass(CenterProfileId.class)
        @Table(name = "user_center_profile")
        public class CenterProfile implements Serializable {

            @Id
            @ManyToOne
            private Center center;
            @Id
            @ManyToOne
            private Profile profile;
            /* getters and setters */

        }

       @Embeddable
    public class CenterProfileId implements Serializable {

        private static final long serialVersionUID = 1L;
        @ManyToOne
        @JoinColumn(name = "idCenter")
        private Center center;
        @ManyToOne
        @JoinColumn(name = "idProfile")
        private Profile profile;

        /* getters, setters, equals, hashcode */
    }

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

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name = "idUser")
    private Long idUser;
    @Column(name = "codUser")
    private String codUser;
    /* other properties */
    @ManyToMany(fetch = FetchType.EAGER)
    @JoinTable(name = "user_center_profile", joinColumns = { @JoinColumn(name = "idUser") }, inverseJoinColumns = {
            @JoinColumn(name = "idCenter"), @JoinColumn(name = "idProfile") })
    private List<CenterProfile> centersProfileUser = new ArrayList<CenterProfile>();
    @Transient
    private Center selectedCenter;

    /* getters, setters */
}

The thing is that at certain point I have to collect all the permissions that a certain user has... I tried several things and I got lazy load errors, no session or session closed errors, problem loading simultaneous bags...

I even tried to write a plain SQL query and I got the same error...

I can't see the way to build a DetachedCriteria for this, and I don't know if it will give an exception too..

My app can connect to different "centers", when he logs in he can choose which center he wants to connect to, but also once logged in, he can change centers... So when he changes it, I have to recalculate his permissions... that's why I need to get that list of permissions..

How could I get this done in a proper way?

Answer 1

In the end, I built the query like this:

HashSet<Permission> set = new HashSet<Permission>();
for (CenterProfile cp : usuario.getCentersProfileUsuario()) {
    // First we build subcriteria to return all the permissions for a certain profile
    DetachedCriteria criteriaProfile = DetachedCriteria
            .forClass(Profile.class);
    criteriaProfile.add(Restrictions.eq("idProfile", cp.getProfile()
            .getIdProfile()));
    criteriaProfile.createAlias("permissions", "permission");
    criteriaProfile.setProjection(Property.forName("permission.idPermission"));
    // Then we build criteria for permissions, which should match the results given by subcriteria
    DetachedCriteria criteria = DetachedCriteria
            .forClass(Permission.class);
    criteria.add(Property.forName("idPermission").in(criteriaProfile));
    List<Permission> permissions = getHibernateTemplate().findByCriteria(
            criteria);
    set.addAll(permissions);
}