How to call google endpoints from android client?

public class SaveProfileTask extends AsyncTask<Void, Void, String> {
    private final String LOG_TAG = SaveProfileTask.class.getSimpleName();
    private MyApi mApi;
    private Profile mProfile;
    private Context mContext;

    public SaveProfileTask(Profile profile, Context context) {
        mProfile = profile;
        mContext = context;
    }

    @Override
    protected String doInBackground(Void... params) {
        if (mApi == null) {
            MyApi.Builder builder = new MyApi.Builder(AndroidHttp.newCompatibleTransport(),
                    new AndroidJsonFactory(), null)
                    // options for running against local devappserver
                    // - 10.0.2.2 is localhost's IP address in Android emulator
                    // - turn off compression when running against local devappserver
                    .setRootUrl("http://10.0.2.2:8080/_ah/api/")
                    .setGoogleClientRequestInitializer(new GoogleClientRequestInitializer() {
                        @Override
                        public void initialize(AbstractGoogleClientRequest<?> abstractGoogleClientRequest) throws IOException {
                            abstractGoogleClientRequest.setDisableGZipContent(true);
                        }
                    });
            mApi = builder.build();
        }

        try {
            return mApi.sayHi(mProfile.getFirstName()).execute().getData();
        } catch (IOException e) {
            return e.getMessage();
        }
    }

    @Override
    protected void onPostExecute(String result) {
        Toast.makeText(mContext, result, Toast.LENGTH_LONG).show();
        Log.d(LOG_TAG, "ERROR: " + result);
    }
}