Examples with SortKey org.forgerock.json.resource.SortKey used on opensource projects

Example 1 with SortKey

use of org.forgerock.json.resource.SortKey in project OpenAM by OpenRock.

the class QueryResponsePresentation method sortItems.

private static List<ResourceResponse> sortItems(final QueryRequest request, List<ResourceResponse> items) {
    Comparator<ResourceResponse> comparator = new Comparator<ResourceResponse>() {

        final List<SortKey> sortKeys = request.getSortKeys();

        @Override
        public int compare(ResourceResponse o1, ResourceResponse o2) {
            int compare = 0;
            for (SortKey key : sortKeys) {
                Comparable<Object> v1 = getField(o1, key.getField());
                Comparable<Object> v2 = getField(o2, key.getField());
                compare = compare(v1, v2, key.isAscendingOrder());
                if (compare != 0) {
                    break;
                }
            }
            return compare;
        }

        private int compare(Comparable<Object> first, Comparable<Object> second, boolean ascending) {
            int result;
            if (first == null && second == null) {
                result = 0;
            } else if (first == null) {
                result = -1;
            } else if (second == null) {
                result = 1;
            } else {
                result = first.compareTo(second);
            }
            if (!ascending) {
                result = -result;
            }
            return result;
        }

        /**
             * Gets the comparable field value from a resource.
             *
             * @param resource The resource.
             * @param field The field.
             * @return The comparable field value or {@code null} if the field is empty or the
             * field value is not comparable.
             */
        private Comparable<Object> getField(ResourceResponse resource, JsonPointer field) {
            JsonValue value = resource.getContent();
            if (value.get(field).isNull()) {
                return null;
            }
            Object object = value.get(field).getObject();
            if (isComparable(object)) {
                return asComparable(object);
            } else {
                return null;
            }
        }

        private boolean isComparable(Object o) {
            return o instanceof Comparable;
        }

        @SuppressWarnings("unchecked")
        private Comparable<Object> asComparable(Object o) {
            return (Comparable<Object>) o;
        }
    };
    try {
        Collections.sort(items, comparator);
    } catch (NullPointerException e) {
    // No-op, sorting failed.
    }
    return Collections.unmodifiableList(items);
}