this code send null pointer exception any one pls correct this and mail me.
objava2@hotmail.com import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class loginServlet extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
boolean b = false;
String userid = req.getParameter ("UTX");
String password = req.getParameter ("PTX");
ServletContext sc = getServletContext();
Vector vec = (Vector)(sc.getAttribute ("user"));
for(int i=0; i<vec.size (); i++) {
Users u = (Users)(vec.get (i));
if(userid.equals (u.userid ) && password.equals (u.password )) {
b=true;
break;
}
else
b=false;
}
if(b==true)
res.sendRedirect("/examples/welcomepg.htm");
else if(b==false)
res.sendRedirect ("/examples/REGFORM.htm");
}
}