EJB Doubts/Questions - HELP

Question

Hi All,
I am new to EJB technology and i am learning EJB without training canter. I am just going through Java EE tutorials available on www.oracle.com .
My knowledge of EJB Session bean say:
1.     Stateful Session Bean     : Maintains the client state.
2.     Stateless Session Bean     : Does not maintain the client state.
Now I am developing Shopping Cart Example using EJB, Servlet, JSP and HTML pages.
My Project contains following pages:
1.     login.html
2.     AuthenticateServlet.java
3.     User.jsp
4.     PurchaseServlet
5.     PurchaseSuccessful.jsp
6.     AuthenticateBean – Stateful Session Bean
7.     AutheticateBeanRemote – Remote Interface of Authenticate Bean
8.     PurchaseBean – StatefulSession Bean
9.     PurchaseBeanRemote -- Remote Interface of PurchaseBean
Session Bean with its remote interface is maintained in the ejb package.
Login.html contains;
1.     textbox named “txtUser”
2.     Password textbox named “txtPass”
3.     Submit Button
On submitting the credentials, it will check for the authentication in the AuthenticateServlet.
AuthenticateBean contains
public boolean authenticate(String user, String pwd)
     if(anylogic)
return true;
     else
          return false;
The above method is exposed in AuthenticateBeanRemote Interface.
2. AuthenticateServlet contains
I have done lookup of AuthenticateBeanRemote and have created abr. Below some important code of AuthenticateServlet;
String user = request.getParamter("txtUser") ;
String pwd = request.getParamter("txtPassr") ;
boolean flag = abr.authenticate(user,pwd);
if(flag)
     // then it will direct the control to User Page
else
out.println("Failure");
User.jsp page will show me the UserID and some task that the authenticated user can do.
My question: is while redirecting the page to User.jsp from AuthenticateServlet, do I need to do URLRewritting to maintain the session or do I need to create separate HTTPSession Object or does the Stateful session bean will take care of session management on its own. i.e. no need to do anything, just transfer or redirect to User.jsp page .
User.jsp has purchase catalog of which the user will select products and click on purchase. On clicking purchase, it will take us to PurchaseServlet.
My question Now in the PurchaseServlet if I have written the code to access the methods in PurchaseBean, Whether it will be a guarantee that the authernticated and currently logged in user is accessing the methods so that only that person’s purchased items are visible and no mishap will occur regarding the user integrity.
PurchaseBean only contains the method to add the amount.
My Question: if at the same time 2-3 users are logging in the application, then whether by using the statefulsession bean, user integrity is maintained. OR do I need to use some other approach.
Please help me... I know these questions are silly but that’s the way the technology can be learned.

Answer 1

user8687589 wrote:
Please help me... I know these questions are silly but that’s the way the technology can be learned.You are SO wrong. You learn it by:
a) reading and studying
b) really understanding not only the technology but also the theory behind the technology
c) learning how it works, why it works, when it works and when you should or shouldn't use it
A common denominator here is that you apply thought, reason and intelligence to get not only the basics but the big picture. Don't learn how to use it: UNDERSTAND it. That does not include just demanding all the answers in a forum and expect to have the answers spoon-fed to you. First read and study, then we'll talk.