For some use cases it makes sense to fetch all the fences at once in the beginning, so we want to have an endpoint to list all fences from a certain group.

listFences_snippet.java

@ApiMethod(name = "list", httpMethod = "get", path = "list")
public ArrayList < MyFence > listFences(@Named("group") String group) {
	ArrayList < MyFence > fences = new ArrayList < MyFence > ();
 
	DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
	Key fenceKey = KeyFactory.createKey("Geofence", group);
 
	Query query = new Query("Fence", fenceKey).addSort("id", Query.SortDirection.DESCENDING);
	List < Entity > fencesFromStore = datastore.prepare(query).asList(FetchOptions.Builder.withDefaults());
 
	if (fencesFromStore.isEmpty()) {
		return fences;
	} else {
		for (Entity fenceFromStore: fencesFromStore) {
			long id = (long) fenceFromStore.getProperty("id");
			String name = (String) fenceFromStore.getProperty("name");
			String description = (String) fenceFromStore.getProperty("description");
			Gson gson = new Gson();
			Text vText = (Text) fenceFromStore.getProperty("vertices");
			String vString = vText.getValue();
			double[][] vertices = gson.fromJson(vString, double[][].class);
 
			MyFence tempFence = new MyFence(id, name, group, description, vertices);
			fences.add(tempFence);
		}
		return fences;
	}
}