Accessing the Wearable Data Layer

This lesson teaches you to

  1. Set up a Google Play services client to use the Wearable Data Layer APIs

Dependencies and Prerequisites

  1. Creating Wearable Apps > Set Up an Android Wear Emulator or Device
  2. Creating Wearable Apps > Creating a Project

To call the Data Layer API, create an instance of GoogleApiClient, the main entry point for any of the Google Play services APIs.

GoogleApiClient provides a builder that makes it easy to create an instance of the client. A minimal GoogleApiClient looks like this:

Note: For now, this minimal client is enough to get started. However, see Accessing Google Play services APIs for more information about creating a GoogleApiClient, implementing its callbacks, and handling error cases.

GoogleApiClient mGoogleApiClient = new GoogleApiClient.Builder(this)
        .addConnectionCallbacks(new ConnectionCallbacks() {
                public void onConnected(Bundle connectionHint) {
                    Log.d(TAG, "onConnected: " + connectionHint);
                    // Now you can use the Data Layer API
                public void onConnectionSuspended(int cause) {
                    Log.d(TAG, "onConnectionSuspended: " + cause);
        .addOnConnectionFailedListener(new OnConnectionFailedListener() {
                public void onConnectionFailed(ConnectionResult result) {
                    Log.d(TAG, "onConnectionFailed: " + result);
        // Request access only to the Wearable API

Important: To avoid client connection errors on devices that do not have the Android Wear app installed, use a separate GoogleApiClient instance to access only the Wearable API. For more information, see Access the Wearable API.

Before you use the data layer API, start a connection on your client by calling the connect() method, as described in Start a Connection. When the system invokes the onConnected() callback for your client, you're ready to use the Data Layer API.