Validation on Redirect

Question

validation.java

     try
    {
        conn = dsEvent.getConnection();
        String userCheck = \"select * from customer\";
        stmt = conn.createState         


        

Answer 1

Seems like the ResultSet contains at least two rows, so the server is executing the forward and/or the redirect or a combination of both at least two times, which is not allowed since you're trying to write the response when it's already closed.

Solution: Move the validation code outside any loop. Make sure the call to RequestDispatcher#forward or HttpServletResponse#redirect occurs once only in your method in servlet.

Also, I don't recommend using redirect in this case, because it generates a new request/response cycle so all the attributes stored in the request won't pass to this new request/response.