/**
* This test provides another demonstration of selecting multiple properties -- with this example
* using a constructor expression to return a typed object for each result in the query.
*/
@Test
public void testMultiSelectConstructor() {
log.info("*** testMultiSelectConstructor() ***");
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<Receipt> qdef = cb.createQuery(Receipt.class);
// select new ejava.jpa.examples.query.Receipt(s.id,s.buyerId,s.date, s.amount)
// from Sale s
Root<Sale> s = qdef.from(Sale.class);
qdef.select(
cb.construct(Receipt.class, s.get("id"), s.get("buyerId"), s.get("date"), s.get("amount")));
TypedQuery<Receipt> query = em.createQuery(qdef);
List<Receipt> results = query.getResultList();
assertTrue("no results", results.size() > 0);
for (Receipt receipt : results) {
assertNotNull("no receipt", receipt);
log.info("receipt=" + receipt);
}
}
@Override
public <C, X> Page<C> findAll(
Specification<T> spec, Class<C> clazz, Selections<T, C, X> selection, Pageable pageable) {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<C> query = builder.createQuery(clazz);
Root<T> root = query.from(getDomainClass());
Predicate predicate = spec.toPredicate(root, query, builder);
if (predicate != null) {
query.where(predicate);
}
query.select(builder.construct(clazz, selection.select(root, query, builder)));
List<Expression<?>> groupBy = query.getGroupList();
Predicate having = query.getGroupRestriction();
if (pageable.getSort() != null) {
query.orderBy(toOrders(pageable.getSort(), root, builder));
}
TypedQuery<C> typeQuery = em.createQuery(query);
return pageable == null
? new PageImpl<>(typeQuery.getResultList())
: readPage(typeQuery, pageable, spec, selection, groupBy, having);
}