Now we need to create an endpoint called add. This endpoint expects a string for the group name, a boolean indicating whether to rebuild our index, and a JSON object representing our fence’s object model. From this we create a new fence and write it to Cloud Datastore.

addFence_snippet.java

@ApiMethod(name = "add", httpMethod = "post", path = "add")
public MyFence addFence(@Named("group") String group, @Named("index") boolean buildIndex, MyFence fence) {
	//Get the last fences' id.
	DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
	Key fenceKey = KeyFactory.createKey("Geofence", group);
 
	long nextId;
	if (fence.getId() != -1) {
		nextId = fence.getId();
	} else {
		long lastId;
		Query query = new Query("Fence", fenceKey).addSort("id", Query.SortDirection.DESCENDING);
		List < Entity > lastFence = datastore.prepare(query).asList(FetchOptions.Builder.withLimit(1));
 
		if (lastFence.isEmpty()) {
			lastId = -1;
		} else {
			lastId = (long) lastFence.get(0).getProperty("id");
		}
		nextId = lastId + 1;
	}
 
	//Create new Entity with nextId.
	Entity fenceEntity = new Entity("Fence", fenceKey);
	fenceEntity.setProperty("id", nextId);
	fenceEntity.setProperty("name", fence.getName());
	fenceEntity.setProperty("description", fence.getDescription());
 
	Gson gson = new Gson();
	String jsonString = gson.toJson(fence.getVertices());
	//Convert to DataStore-Text-Object to store the vertices.
	Text jsonText = new Text(jsonString);
	fenceEntity.setProperty("vertices", jsonText);
	//Write to DataStore.
	datastore.put(fenceEntity);
 
	MyFence newFence = new MyFence();
	newFence.setId(nextId);
 
	//Rebuild the Index.
	if (buildIndex) {
		try {
			MyIndex.buildIndex(group);
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
 
	return newFence;
}