Android app: Basic accelerometer

AccelerometerActivity.java

public class AccelerometerActivity extends ActionBarActivity implements SensorEventListener{

    private String restURL;
    private TextView acceleration;
    private CassandraRestApi cassandraRestApi;
    //...

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        //...
        //get params passed from startActivity
        Bundle extras = getIntent().getExtras();
        if (extras != null) {
            restURL = extras.getString(StartActivity.URL);
        }

        // define restApi endpoint and mapping
        RestAdapter restAdapter = new RestAdapter.Builder()
                .setEndpoint(restURL)
                .build();
        cassandraRestApi = restAdapter.create(CassandraRestApi.class);
        //...
    }
    //...

    @Override
    public void onSensorChanged(SensorEvent event) {
        Acceleration capturedAcceleration = getAccelerationFromSensor(event);
        //...
        new SendAccelerationAsyncTask().execute(capturedAcceleration);
    }
    //...
    
    /**
     * Asyncronous task to post request to a Rest API.
     */
    private class SendAccelerationAsyncTask extends AsyncTask<Acceleration, Void, Void>{

        @Override
        protected Void doInBackground(Acceleration... params) {
            try {
                cassandraRestApi.sendAccelerationValues(params[0]);
            } catch(Exception e) {
                e.printStackTrace();
            }
            return null;
        }
    }
}