code: static MD5Hash getFileClient(String nnHostPort,
        String queryString, List<OutputStream> outputStreams,
        Storage dstStorage, boolean getChecksum) throws IOException {
  
      String proto = "http://";
      StringBuilder str = new StringBuilder(proto+nnHostPort+"/getimage?");
      str.append(queryString);
      LOG.info("Opening connection to " + str);
      //
      // open connection to remote server
      //
      URL url = new URL(str.toString());
      return doGetUrl(url, outputStreams, dstStorage, getChecksum);
    }
docs: Client-side Method to fetch file from a server
  Copies the response from the URL to a list of local files.
  @param dstStorage if an error occurs writing to one of the files,
  this storage object will be notified.
  @Return a digest of the received file if getChecksum is true