private <C, X> Subquery<?> createCountSubQuery(
Root<T> root,
CriteriaQuery<Long> countQuery,
Selections<T, C, X> selection,
CriteriaBuilder builder,
Specification<T> spec,
List<Expression<?>> groupBy,
Predicate having) {
Subquery<?> subquery = countQuery.subquery(entityInformation.getIdType());
Root subRoot = subquery.from(entityInformation.getJavaType());
Expression[] select = selection.select(subRoot, (AbstractQuery<C>) subquery, builder);
subquery.select(select[0]);
selection.join(subRoot, builder);
Predicate predicate =
builder.equal(
subRoot.get(entityInformation.getIdAttribute()),
root.get(entityInformation.getIdAttribute()));
if (predicate != null) {
subquery.where(predicate);
}
if (groupBy != null) {
subquery.groupBy(groupBy);
}
if (having != null) {
subquery.having(having);
}
return subquery;
}
private <C, X> TypedQuery<Long> getCountQuery(
Specification<T> spec,
Selections<T, C, X> selection,
List<Expression<?>> groupBy,
Predicate having) {
CriteriaBuilder builder = em.getCriteriaBuilder();
CriteriaQuery<Long> countQuery = builder.createQuery(Long.class);
Root<T> root = countQuery.from(getDomainClass());
Subquery<?> subquery =
createCountSubQuery(root, countQuery, selection, builder, spec, groupBy, having);
Path<?> path = root.get(entityInformation.getIdAttribute());
countQuery.select(builder.countDistinct(path)).where(builder.exists(subquery));
return em.createQuery(countQuery);
}
