Thank you, Gunther
The goal is to manage an hypotetical videoclub (don't know how to say it in English, rent films shop?). So we have a PostgreSQL database underneath with several tables saving data. We have persons that are divided in customers/employees that can be loged as users of the application. Each user has a rol and not every rol can do the same. After 3 minutes of inactivity, the system automatically logout the user.
My main goal is to divide the presentation layer (jsp) from the database access (in java classes) that are conected by java beans. Also, the database queries are in an external xml file that are readed by the java routines that provides information to jsp in array of strings.
Regards