Android 액티비티 백키 처리

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub

        switch (keyCode) {
            case KeyEvent.KEYCODE_BACK:
                Toast.makeText(this, "Back키를 누르셨군요", Toast.LENGTH_SHORT).show();
                break;
        }
        return super.onKeyDown(keyCode, event);
    }