HTML form input fields add null values to MySQL database

Question

I have the below html form where a user reserves a room. I am trying to get the data entered by the user in the jsp code as shown but all the values in the database are added as null except for the "user_email" field which is taken as an attribute dispatched from a servlet. Is there any problem with my code? If so, how can I get the values from the input fields of this form and submit them to the jsp code below.

<%@ page language="java" contentType="text/html; charset=ISO-8859-1" import = "com.user.*"
        pageEncoding="ISO-8859-1"%>
    
    
    
    
    Reservation
    
    
    
    

    Reservation
    
    
        
            Please complete your reservation
           

        
            Arrival Date
            
            
            
        
        
            Number of rooms
            
                    

        
        
            Number of nights
            

    

        

        
        Room type:
        
        

    


    
    
    <%  

        String d = request.getParameter("day");
        String m = request.getParameter("month");
        String y = request.getParameter("year");
        String r = request.getParameter("roomNo");
        String n = request.getParameter("nights");
        String rt = request.getParameter("rType");
        String em = String.valueOf(request.getAttribute("email"));

        ReservationDb rd = new ReservationDb();
        rd.insert(d, m, y, r, n, rt, em);
    %>

//Insert function

public void insert(String d, String m, String y, String r, String n, String rt, String em) {
            Connection connection = null;
            PreparedStatement ppStm = null;

            try {
                connection = ConnectionConfiguration.getConnection();
                ppStm = connection.prepareStatement("INSERT INTO reservations (res_day,res_month,res_year,no_rooms,"
                        + "no_nights,room_type,user_email)"
                        + "VALUES (?,?,?,?,?,?,?)");

                int count = 1;
                ppStm.setString(count++, d);
                ppStm.setString(count++, m);
                ppStm.setString(count++, y);
                ppStm.setString(count++, r);
                ppStm.setString(count++, n);
                ppStm.setString(count++, rt);
                ppStm.setString(count++, em);
                ppStm.executeUpdate();

            } catch(Exception e) {
                e.printStackTrace();
            } finally {

                if (ppStm != null){
                    try {
                        ppStm.close();
                    } catch (SQLException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }

                        }
                if (connection != null) {
                        try {
                            connection.close();
                        } catch (SQLException e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                    }
                }
            }

        }

Ravinder Reddy · Accepted Answer

It seems you are reading parameters on the same jsp page where input form is defined.
It is not wrong but, before reading parameters, you are not checking if the form is submitted or not.

Simple solution is:

check for existence of specific parameter in the request,

if it is present then read all other parameters.
- then perform insert operation.
if it is not present then don't read any other parameter
- and don't perform insert operation.

Example:

<%  
    String operation = request.getParameter("operation");
    if ( operation != null and operation.equals( "addreservation" ) )
    {
        String d = request.getParameter("day");
        String m = request.getParameter("month");
        String y = request.getParameter("year");
        String r = request.getParameter("roomNo");
        String n = request.getParameter("nights");
        String rt = request.getParameter("rType");
        String em = String.valueOf(request.getAttribute("email"));

        ReservationDb rd = new ReservationDb();
        rd.insert(d, m, y, r, n, rt, em);
    }
    else
    {
        // ignore reading parameters
    }
;
%>

HTML form input fields add null values to MySQL database

Answers (2)

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