Here are the examples of the java api class com.google.appengine.api.search.SortExpression taken from open source projects.
1. PlacesHelper#getPlaces()
Project: solutions-mobile-shopping-assistant-backend-java
File: PlacesHelper.java
File: PlacesHelper.java
static List<PlaceInfo> getPlaces(GeoPt location, long distanceInMeters, int resultCount) { // TODO(user): Use memcache String geoPoint = "geopoint(" + location.getLatitude() + ", " + location.getLongitude() + ")"; String query = "distance(place_location, " + geoPoint + ") < " + distanceInMeters; String locExpr = "distance(place_location, " + geoPoint + ")"; SortExpression sortExpr = SortExpression.newBuilder().setExpression(locExpr).setDirection(SortExpression.SortDirection.ASCENDING).setDefaultValueNumeric(distanceInMeters + 1).build(); Query searchQuery = Query.newBuilder().setOptions(QueryOptions.newBuilder().setSortOptions(SortOptions.newBuilder().addSortExpression(sortExpr))).build(query); Results<ScoredDocument> results = getIndex().search(searchQuery); if (results.getNumberFound() == 0) { // geo-location doesn't work under dev_server if (environment.value() == Development) { // return all documents results = getIndex().search("value > 0"); } } List<PlaceInfo> places = new ArrayList<PlaceInfo>(); for (ScoredDocument document : results) { if (places.size() >= resultCount) { break; } GeoPoint p = document.getOnlyField("place_location").getGeoPoint(); PlaceInfo place = new PlaceInfo(); place.setplaceID(document.getOnlyField("id").getText()); place.setName(document.getOnlyField("name").getText()); place.setAddress(document.getOnlyField("address").getText()); place.setLocation(new GeoPt((float) p.getLatitude(), (float) p.getLongitude())); // and use double comparison with epsilon set to 0.0001 if (Math.abs(p.getLatitude()) <= 0.0001 && Math.abs(p.getLongitude()) <= 0.0001) { // set a fake distance of 5+ km place.setDistanceInKilometers(5 + places.size()); } else { double distance = distanceInMeters / 1000; try { distance = getDistanceInKm(p.getLatitude(), p.getLongitude(), location.getLatitude(), location.getLongitude()); } catch (Exception e) { log.warning("Exception when calculating a distance: " + e.getMessage()); } place.setDistanceInKilometers(distance); } places.add(place); } return places; }