Question

I have a JSF webapp throwing an exception (see below) when I’m trying to query for entities mapped with Hibernate. What am I doing wrong? Or is it a Bug in Hibernate? How can I fix that? Thanks for your help 🙂

Here are the relevant classes:

Base class ShipmentUnit with some sub-classes:

@Entity
@Table(name = "tat_shipment_unit")
@Inheritance(strategy = SINGLE_TABLE)
@DiscriminatorColumn(name = "unit_type", discriminatorType = CHAR, length = 1)
@DiscriminatorValue("_")
public abstract class ShipmentUnit implements Serializable {
    private Long id;
    private List<ShipmentAction> actions;

    @Id @GeneratedValue
    public Long getId() { return id; }  // and corresponding setter

    @OneToMany(mappedBy = "unit")
    @OrderBy("listIndex")
    public List<ShipmentAction> getActions() { return actions; }  // and setter

    // hashCode, equals etc.
}

The ShipmentAction class:

@Entity
@Table(name = "tat_shipment_action")
@IdClass(ShipmentActionID.class)
public class ShipmentAction implements Serializable {
    private ShipmentUnit unit;
    private int listIndex;

    @Id @ManyToOne @NotNull
    public ShipmentUnit getUnit() { return unit; }  // and setter

    @Id @Column(name = "list_index", nullable = false)
    public int getListIndex() { return listIndex; } // and setter
}

The ShipmentActionID class also has the unit and listIndex properties with the same signatures on the getter and setter methods.

Now, I want to display a h:dataTable with a LazyDataModel<ShipmentAction>. The implementation of the data model uses the Criteria API to (1) count and (2) query for those shipment action entities, like so:

CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Number> query = cb.createQuery(Number.class);
Root<ShipmentAction> root = query.from(ShipmentAction.class);
Predicate predicates = ...
int total = em.createQuery(
    query.select(cb.count(root).where(predicates)
).getSingleResult().intValue();

At the moment the TypedQuery should be created with em.createQuery(...) an exception is being thrown:

[SEVERE] Error Rendering View[/tat/report/actions.xhtml]: java.lang.IllegalStateException: No supertype found
at org.hibernate.ejb.metamodel.AbstractIdentifiableType.requireSupertype(AbstractIdentifiableType.java:85)
at org.hibernate.ejb.metamodel.AbstractIdentifiableType.getIdType(AbstractIdentifiableType.java:173)
at org.hibernate.ejb.criteria.expression.function.AggregationFunction$COUNT.renderArguments(AggregationFunction.java:110)
at org.hibernate.ejb.criteria.expression.function.ParameterizedFunctionExpression.render(ParameterizedFunctionExpression.java:94)
at org.hibernate.ejb.criteria.expression.function.BasicFunctionExpression.renderProjection(BasicFunctionExpression.java:71)
at org.hibernate.ejb.criteria.QueryStructure.render(QueryStructure.java:250)
at org.hibernate.ejb.criteria.CriteriaQueryImpl.render(CriteriaQueryImpl.java:338)
at org.hibernate.ejb.criteria.CriteriaQueryCompiler.compile(CriteriaQueryCompiler.java:223)
at org.hibernate.ejb.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:619)

I am using Hibernate Version 4.0.0.Final, running on JBoss AS 7.

        <dependency>
        <groupId>org.hibernate.javax.persistence</groupId>
        <artifactId>hibernate-jpa-2.0-api</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.jboss.spec.javax.ejb</groupId>
        <artifactId>jboss-ejb-api_3.1_spec</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.jboss.spec.javax.annotation</groupId>
        <artifactId>jboss-annotations-api_1.1_spec</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>javax.enterprise</groupId>
        <artifactId>cdi-api</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>javax.validation</groupId>
        <artifactId>validation-api</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-validator</artifactId>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>4.0.0.Final</version>
        <scope>provided</scope>
    </dependency>

Answer 1

I found a solution to my problem. I changed the mapping of the dependent class ShipmentAction by using an @EmbeddedId instead of two @Id annotations. In case you’re interested, here is the updated class (the mapping of the ShipmentUnit class has not changed ¹)

@Entity
@Table(name = "tat_shipment_action")
public class ShipmentAction implements Serializable {
    private @EmbeddedId Key id;
    private @MapsId("unit_id") @ManyToOne ShipmentUnit unit;

    public ShipmentAction() {
        id = new Key();
    }

    public ShipmentUnit getUnit() { return unit; }  // and setter

    public int getListIndex() {
        return id.list_index;
    }

    public void setListIndex(int index) {
        id.list_index = index;
    }

    @Embeddable
    public static class Key implements Serializable {
        public long unit_id;
        public int list_index;
        // hashCode() and equals()
    }
}

Okay, this seems to work and my LazyDataModel<ShipmentAction> likes it now 🙂
But the only strange thing is, that this only works with JPA annotations on the fields, Hibernate can’t cope with these annotations on the getter-methods anymore (at least on the classes affected by my change). Any thoughts on that one?

¹ One other little change: the @javax.persistence.OrderBy annotation at ShipmentUnit.getActions() had to be replaced with @org.hibernate.annotations.OrderBy for whatever reason.