使用 Hibernate Criteria 并限制不同的关系属性

Question

So I'm working on a Court like application based on JSF 2.3 Hibernate 4.3 and I'm struggling to figure out how to build a given query using Hibernate Criteria API. The idea is to select all processes the authenticated user is involved with.

The entities involved are simplified below:

User.java

@Entity
@Table(name = "tb_users")
public class User implements Serializable {
    
    @Id
    @GeneratedValue
    private Long id;
    
    @ManyToOne
    private User lawyer;
    
    /* other attributes, getters, setters... */
}

Process.java

@Entity
@Table(name = "tb_processes")
public class Process implements Serializable {

    @Id
    @GeneratedValue
    private Long id;

    @ManyToOne
    private User judge;

    @ManyToOne
    private User promoterParty;

    @ManyToOne
    private User promotedParty;
    
    /* other attributes, getters, setters... */
}

In my bean, I want to list the processes which the user is involved in some level (as judge OR as party OR as party's lawyer). So this is the closest I could get using Criateria API:

@Named
@RequestScoped
public class IndexBean implements Serializable {
    
    @Inject
    private ExternalContext externalContext;

    public List<Process> getProcesses() {
        HttpSession httpSession = (HttpSession) externalContext.getSession(false);
        User user = (User) httpSession.getAttribute("auth");
        
        Criteria criteria = dao.criteria(Process.class);
        criteria.add(Restrictions.or(
        /* 1 */  Restrictions.eq("judge.id", user.getId()),                // works fine
        /* 2 */    Restrictions.eq("promoterParty.id", user.getId()),        // works fine 
        /* 3 */    Restrictions.eq("promotedParty.id", user.getId()),        // works fine
        /* 4 */    Restrictions.eq("promoterParty.lawyer.id", user.getId()), // [fail] org.hibernate.QueryException: could not resolve property: promoterParty.lawyer.id of: com.example.model.Process
        /* 5 */    Restrictions.eq("promotedParty.lawyer.id", user.getId())  // [fail] org.hibernate.QueryException: could not resolve property: promotedParty.lawyer.id of: com.example.model.Process
        ));
        
        return criteria.list();
    }
}

The challange is to add the restriction to the relationship of the relationship (4 and 5), while the other ones alone work fine.

Can someone help me figure out how I can build this query?

Answer 1

I did something like this and it seems to work - generated query does not look super clean (and I wouldn't expect it to):

Criteria criteria = sess.createCriteria(Process.class);
criteria
    .createAlias("promoterParty.lawyer", "promoterLawyer")
    .createAlias("promotedParty.lawyer", "promotedLawyer")
    .add(Restrictions.or(
        Restrictions.eq("judge.id", "123"),
        Restrictions.eq("promoterLawyer.id", "123"),
        Restrictions.eq("promotedLawyer.id", "123")
    ));

Aliases are the key thing here, don't worry about 123 :)