I am in process to create a new application, My requirement here is that I want to create a reusable module that I want to use for authentication & authorization. Further I want that when ever a user logs-in, his/her privileges get stored in the session and based on the data stored in the database s/he should be able to view the page and event the fields/components on it. Can any one help me with the design of the above requirement or at least point me to some link. Thanks in advance for the same.
Your computer system is like AC, it's of no use when you open Windows ;)
Acegi Security may be of interest as it provides the functionality you have described, it's based on the Spring Framework, but will save re-implementing the wheel.
It also includes a JSP Tag library for protecting links/content on the page.