@RequestMapping
  public void gen(GenCmd genCmd, HttpServletRequest request, HttpServletResponse response)
      throws Exception {
    String outputPath = outputRootDir + System.currentTimeMillis();
    genCmd.setOutputRootDir(outputPath);
    genCmd.execute();

    response.setHeader(
        "Content-Disposition", "attachment; filename=\"" + "generatorOutput.zip" + "\"");
    ZipHelper.zip(outputPath, response.getOutputStream());
  }