@Override
public final List<Product> findByFeatures(final Map<Integer, List<String>> featureValues) {
CriteriaBuilder builder = manager.getCriteriaBuilder();
CriteriaQuery<Product> criteriaQuery = builder.createQuery(Product.class);
Root<Product> product = criteriaQuery.from(Product.class);
Path<ProductFeature> feature = product.join("features");
CriteriaQuery<Product> select = criteriaQuery.select(product);
Predicate featurePredicate = builder.disjunction();
for (final Map.Entry<Integer, List<String>> fValue : featureValues.entrySet()) {
Predicate equalFeatureId = builder.equal(feature.get("featureId"), fValue.getKey());
List<String> values = fValue.getValue();
Predicate equalsValues = builder.disjunction();
for (String value : values) {
Predicate equalFeatureVal = builder.equal(feature.get("value"), value);
equalsValues = builder.or(equalsValues, equalFeatureVal);
}
featurePredicate = builder.or(featurePredicate, builder.and(equalFeatureId, equalsValues));
}
select.where(featurePredicate);
select.groupBy(product.get("id"));
select.having(builder.equal(builder.count(product), featureValues.size()));
TypedQuery<Product> query = manager.createQuery(criteriaQuery);
return query.getResultList();
}
