code: private String getHostHeaderForHost(String hostName) {
          List<ServerRedirect> servers = serverRedirectService.tableServers(requestInformation.get().client.getId());
          for (ServerRedirect server : servers) {
              if (server.getSrcUrl().compareTo(hostName) == 0) {
                  String hostHeader = server.getHostHeader();
                  if (hostHeader == null || hostHeader.length() == 0) {
                      return null;
                  }
                  return hostHeader;
              }
          }
          return null;
      }
docs: Obtain host header value for a hostname
  
  @param hostName
  @return