try {
            final long count = ComponentUtil.getThumbnailManager().purge(getExpiry());
            return "Deleted " + count + " thumbnail files.";
        } catch (final Exception e) {
            logger.error("Failed to purge thumbnails.", e);
            return e.getMessage();
        }
    }

    public long getExpiry() {
        return expiry;
    }

    public PurgeThumbnailJob expiry(final long expiry) {