[Résolu] Spécifier les interfaces et définir les méthodes

public class MainActivity extends FragmentActivity implements
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener {
  
    @Override
    public void onConnected(Bundle dataBundle) {
        // Display the connection status
        Toast.makeText(this, "Connected", Toast.LENGTH_SHORT).show();

    }
    ...
    
    @Override
    public void onDisconnected() {
        // Display the connection status
        Toast.makeText(this, "Disconnected. Please re-connect.",
                Toast.LENGTH_SHORT).show();
    }
    ...
    
    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        
        if (connectionResult.hasResolution()) {
            try {
                // Start an Activity that tries to resolve the error
                connectionResult.startResolutionForResult(
                        this,
                        CONNECTION_FAILURE_RESOLUTION_REQUEST);
                
            } catch (IntentSender.SendIntentException e) {
                // Log the error
                e.printStackTrace();
            }
        } else {
          
            showErrorDialog(connectionResult.getErrorCode());
        }
    }
    ...
}