Android非表示システムステータスバー

private static boolean isStatusbarVisible(Activity activity) {
        int uiOptions = activity.getWindow().getDecorView().getSystemUiVisibility();
        boolean isStatusbarHide = ((uiOptions | View.SYSTEM_UI_FLAG_FULLSCREEN) == uiOptions);
        return !isStatusbarHide;
    }

public static void hideStatusBar(Activity activity) {
        if (isStatusbarVisible(activity)) {
            int uiOptions = activity.getWindow().getDecorView().getSystemUiVisibility();
            uiOptions |= View.SYSTEM_UI_FLAG_FULLSCREEN;
            activity.getWindow().getDecorView().setSystemUiVisibility(uiOptions);
        }
    }