private void doSamlRedirect(HttpServletRequest request, HttpServletResponse response)
      throws HttpSamlAuthenticationException {
    HiveSaml2Client.get(hiveConf).setRedirect(request, response);
  }
Generate a SAML Authentication request using HTTP-Redirect binding.
service/src/java/org/apache/hive/service/cli/thrift/ThriftHttpServlet.java