@SuppressWarnings("unchecked")
static <T> Expression<T> toExpressionRecursively(From<?, ?> from, PropertyPath property) {
Bindable<?> propertyPathModel = null;
Bindable<?> model = from.getModel();
String segment = property.getSegment();
if (model instanceof ManagedType) {
/*
* Required to keep support for EclipseLink 2.4.x. TODO: Remove once we drop that (probably Dijkstra M1)
* See: https://bugs.eclipse.org/bugs/show_bug.cgi?id=413892
*/
propertyPathModel = (Bindable<?>) ((ManagedType<?>) model).getAttribute(segment);
} else {
propertyPathModel = from.get(segment).getModel();
}
if (requiresJoin(propertyPathModel, model instanceof PluralAttribute)
&& !isAlreadyFetched(from, segment)) {
Join<?, ?> join = getOrCreateJoin(from, segment);
return (Expression<T>)
(property.hasNext() ? toExpressionRecursively(join, property.next()) : join);
} else {
Path<Object> path = from.get(segment);
return (Expression<T>)
(property.hasNext() ? toExpressionRecursively(path, property.next()) : path);
}
}
@SuppressWarnings("unchecked")
static <T> Expression<T> toExpressionRecursively(From<?, ?> from, PropertyPath property) {
Bindable<?> propertyPathModel = null;
if (from.getModel() instanceof ManagedType) {
/*
* Avoid calling from.get(...) because this triggers the generation of an inner-join instead
* of and outer-join in eclipse-link.
* See: https://bugs.eclipse.org/bugs/show_bug.cgi?id=413892
*/
propertyPathModel =
(Bindable<?>) ((ManagedType<?>) from.getModel()).getAttribute(property.getSegment());
} else {
propertyPathModel = from.get(property.getSegment()).getModel();
}
if (property.isCollection() || requiresJoin(propertyPathModel)) {
Join<?, ?> join = getOrCreateJoin(from, property.getSegment());
return (Expression<T>)
(property.hasNext() ? toExpressionRecursively(join, property.next()) : join);
} else {
Path<Object> path = from.get(property.getSegment());
return (Expression<T>)
(property.hasNext() ? toExpressionRecursively(path, property.next()) : path);
}
}
/**
* @see DATAJPA-403
*/
@Test
public void reusesExistingJoinForExpression() {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<User> query = builder.createQuery(User.class);
Root<User> from = query.from(User.class);
PropertyPath managerFirstname = PropertyPath.from("manager.firstname", User.class);
PropertyPath managerLastname = PropertyPath.from("manager.lastname", User.class);
QueryUtils.toExpressionRecursively(from, managerLastname);
QueryUtils.toExpressionRecursively(from, managerFirstname);
assertThat(from.getJoins(), hasSize(1));
}
/**
* @see DATAJPA-401
*/
@Test
public void doesNotCreateAJoinForNonOptionalAssociation() {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<Order> query = builder.createQuery(Order.class);
Root<Order> root = query.from(Order.class);
QueryUtils.toExpressionRecursively(root, PropertyPath.from("customer", Order.class));
}
/**
* @see DATAJPA-454
*/
@Test
public void createsJoingToTraverseCollectionPath() {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<User> query = builder.createQuery(User.class);
Root<User> root = query.from(User.class);
QueryUtils.toExpressionRecursively(root, PropertyPath.from("colleaguesLastname", User.class));
assertThat(root.getJoins(), hasSize(1));
}
/**
* @see DATAJPA-401
*/
@Test
public void createsJoinForOptionalAssociation() {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<User> query = builder.createQuery(User.class);
Root<User> root = query.from(User.class);
QueryUtils.toExpressionRecursively(root, PropertyPath.from("manager", User.class));
assertThat(root.getJoins(), hasSize(1));
}
/**
* Creates a criteria API {@link javax.persistence.criteria.Order} from the given {@link Order}.
*
* @param order the order to transform into a JPA {@link javax.persistence.criteria.Order}
* @param root the {@link Root} the {@link Order} expression is based on
* @param cb the {@link CriteriaBuilder} to build the {@link javax.persistence.criteria.Order}
* with
* @return
*/
@SuppressWarnings("unchecked")
private static javax.persistence.criteria.Order toJpaOrder(
Order order, Root<?> root, CriteriaBuilder cb) {
PropertyPath property = PropertyPath.from(order.getProperty(), root.getJavaType());
Expression<?> expression = toExpressionRecursively(root, property);
if (order.isIgnoreCase() && String.class.equals(expression.getJavaType())) {
Expression<String> lower = cb.lower((Expression<String>) expression);
return order.isAscending() ? cb.asc(lower) : cb.desc(lower);
} else {
return order.isAscending() ? cb.asc(expression) : cb.desc(expression);
}
}
static Expression<Object> toExpressionRecursively(Path<Object> path, PropertyPath property) {
Path<Object> result = path.get(property.getSegment());
return property.hasNext() ? toExpressionRecursively(result, property.next()) : result;
}