code: protected final MetaProperties getMetaFile(String url) throws UpdateException {
          try {
              final String metaUrl = url.substring(0, url.length() - 7) + "meta";
              final URL u = new URL(metaUrl);
              final Downloader d = new Downloader(settings);
              final String content = d.fetchContent(u, true);
              return new MetaProperties(content);
          } catch (MalformedURLException ex) {
              throw new UpdateException("Meta file url is invalid: " + url, ex);
          } catch (InvalidDataException ex) {
              throw new UpdateException("Meta file content is invalid: " + url, ex);
          } catch (DownloadFailedException ex) {
              throw new UpdateException("Unable to download meta file: " + url, ex);
          }
      }
docs: Downloads the NVD CVE Meta file properties.
  
  @param url the URL to the NVD CVE JSON file
  @return the meta file properties
  @throws UpdateException thrown if the meta file could not be downloaded