Consider a web-based application that facilitates the auction of various kinds of merchandise between interested parties. A simple implementation for such an application will require the users to be in one of three abstract roles, namely Buyer, Seller, or Administrator. Buyers in this application will have access to web pages that display the listed auction items, whereas the Sellers may have access to web pages that allow them to list their merchandise for new auctions. The Administrators may have access to yet another set of web pages that allow them to finalize or cancel existing auctions in whatever state they may be in. Using the deployment descriptors, the application developer can express this intent by protecting such components using abstract security role names.
These abstract role names in turn can be mapped to real principals in a J2EE agent. For example, the role Buyer may be mapped to an OpenSSO Enterprise role called Bidder, the role Seller to an OpenSSO Enterprise role called Vendor, and the role Administrator to an OpenSSO Enterprise role called Admin. The abstract role names used by the application developer can be used to protect the necessary web pages and any specialized Enterprise JavaBeans (EJB) components from unauthorized access by using declarative as well as programmatic security. Once this application is deployed and configured, the agent will ensure that only the authorized personnel get access to these protected resources.
For example, access to the pages meant for Sellers to list their merchandise for auctions will be granted to user Deepak only if this user belongs to the OpenSSO Enterprise role called Vendor. Similarly, users Scott and Gina can place bids on this listed item only if they belong to the role called Bidder. Once the auction period expires, the auction can be finalized by user Krishnendu only if he is in the role called Admin.