code: @SuppressWarnings({ "unchecked" })
      private Predicate convertParametersToPredicate(Root<?> from, CriteriaQuery<?> query) {
          List<Predicate> predicates = new ArrayList<>();
          for (Map.Entry<String, Set<Object>> value : request.getParameters().entrySet()) {
              Subquery<JPAEntry> subquery = buildJPAEntrySubquery(value.getKey(), value.getValue(), from, query);
              predicates.add(builder.exists(subquery));
          }
          if (request.isAndJoined()) {
              return builder.and(Iterables.toArray(predicates, Predicate.class));
          } else {
              return builder.or(Iterables.toArray(predicates, Predicate.class));
          }
      }
docs: Converts a query request parameter map for a query operation into a list of predicates which need to be added to
  the criteria query.