The user login process is implemented by: Signonfilter, which is applied here. There are two types of pages in PetStore, protected and not protected. If the user requests an unprotected page, this page will be displayed directly to the user; if the user requests a protected page, then signonfilter will block the user's request, check if the user is a user who has been logged in, if Yes, the page is displayed directly, and if it is not passed to the landing page. Whether it is a protected page is a flow chart declared in Singon-Config.xml: Signonfilter is only responsible for verifying whether to log in user, registering new users complete (CreateHtmLAction). Create and execute this HTMLAction by RequestProcessor, Action Returns a CREATEUSEREVENT to EJB ControlR (EJBControllerLocaleJB), performs an EJB Action (CreteuseRejbAction) Interagram with EJB Controlor.
