Web login (JSP, Servlet) with roles and users list stored using db4o

Question

Dear all,
I would be grateful if someone of you (the masters out there) could help me with the build of an application where the first page will be a login page.
The users will be devided in 3 categories (user, editor, administrator) and there member information will be saved in db4o database.
If the user has not been registered in the past then a registration page should come up allowing him to be registered and keep his details in a db4o database on the same site.
I am using JSEE8 and the site will be sent to a Tomcat server on the net.
Please please please HELP

Answer 1

I am giving some code for to redirect as the user is, But before that you have to made a extra coloumn "role" in your security table. and put admin, user as respective roles.
doPost(HttpReq...........)
String user = req.getParameter("UserName"):
String pass= req.getParameter("Password");
Then Connect the database with ur code ie class.forName etc
String sql= "Select * from security_table where Username= ' "+user+" ' and Password= ' "+pass+" ' ";
Statement stmt = conn.createStatement();
ResultSet rs= stmt.exequteQuary(sql);
if(rs.next)
String S1=rs.getString("Username");
String S2= rs.getString("Password");
String S3= rs.getString("Role");
if(S1.equals(user) && S2.equals(pass) && S3.equals.(admin)){
req.sendRedirect(http:// full path name of the page)
else if( S1.equals(user) && S2.equals(pass) && S3.equals.(user))
req.sendRedirect(http:// full path name of the page)
}else
req.sendRedirect(http:// full path name of the Error page)
}