Calling javax.persistence.criteria.Path.get(String name) fails for the simple class hierarchy detailed below. The call succeeds if @IdClass and 2nd id field (i.e. id2) are removed. Anyone know why this is so. Does this mean it is not possible to query on a single id field where that id field forms part of a composite key?
failing call is: Path path = entity.get(name);
private static final EntityManager em;
private final CriteriaBuilder cb = em.getCriteriaBuilder();
private final CriteriaQuery query = cb.createQuery(Y.class);
private final Root entity = query.from(Y.class);
static {
Map properties = new HashMap();
// initialise properties appropriately
EntityManagerFactory emf =
Persistence.createEntityManagerFactory("test", properties);
em = emf.createEntityManager();
}
interface PK {
Object getPK();
}
public static class YPK implements Serializable {
int id;
int id2;
YPK(int id, int id2) { }
// Override hashCode() and equals() appropriately
}
@IdClass(YPK.class)
@Entity
public static class Y implements Serializable, PK {
@Id
int id;
@Id
int id2;
protected Y() { }
public Y(int id) {
this.id = id;
}
@Override
public Object getPK() {
return id;
}
}
@Test
public void simpleTest() {
List yy = new ArrayList();
Y yX1 = new Y(5);
yy.add(yX1);
Y yX2 = new Y(6);
yy.add(yX2);
saveItems(yy);
String name = "id";
Path path = entity.get(name);
Predicate restriction = cb.conjunction();
restriction = cb.and(restriction, cb.and(new Predicate[]{cb.equal(path, 5)}));
TypedQuery tq = em.createQuery(this.query);
Y result = null;
try {
result = tq.getSingleResult();
} catch (NoResultException e) {
}
assertNotNull(result);
}
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