Broadleaf Commerce Discussion Forums

I am new of Broadleaf. I followed the official tutorial from here and try to modify my sitemap, but I still have no idea how to start. When I connected to domain.com/sitemaps.gz , the eclipse showed "SiteMapServiceImp - No SiteMap generated since no active configuration was found." I tracked down into the implementations and found it seems to read configuration from the database.

I like to know how can I setup a config and customize a new SiteMapGenerators and hook up to SiteMapService.

Thanks a lot.