Can you please apply comments upon my coding tech....

Question

I use a servlet to send data from a form to a Mysql database.
The servlet code is the following.
When i submit the form i receive an Error 500 from Tomcat upon the 69th line of the code.
The code has as follows.
package mypackage;
import java.sql.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class GroupRegistration extends HttpServlet
Connection con;
public void doPost (HttpServletRequest req, HttpServletResponse res)
                         throws ServletException, java.io.IOException
     handleForm(req, res);
public void init() throws ServletException {
     try{
     /* Loading the driver for the database */
     Class.forName("com.mysql.jdbc.Driver");
     Connection con = DriverManager.getConnection("jdbc:mysql://localhost/se?user=luser&password=Ztgtkpz2");
     catch (ClassNotFoundException e) {
     throw new UnavailableException("Couldn't load JdbcOdbcDriver");
     catch (SQLException e) {
     throw new UnavailableException("Couldn't get db connection");
     private void handleForm(HttpServletRequest req, HttpServletResponse res)
     throws ServletException {
     //ServletOutputStream out = res.OutputStream();
     //res.setContentType("text/html");
     //Extract the form Data Here
     String group = req.getParameter("GroupNo");
     String Name1 = req.getParameter("Name1");
     String LoginID1 = req.getParameter("LoginID1");
     String Name2 = req.getParameter("Name2");
     String LoginID2 = req.getParameter("LoginID2");
     String Name3 = req.getParameter("Name3");
     String LoginID3 = req.getParameter("LoginID3");
     String Name4 = req.getParameter("Name4");
     String LoginID4 = req.getParameter("LoginID4");
     String URL = req.getParameter("URL");
     String Title2 = req.getParameter("Title2");
     String date = req.getParameter("date");
     String INSERT = "INSERT INTO registration (groupno, name1, loginid1, name2, loginid2, name3, loginid3, name4, loginid4, url, topic, date) VALUES (" + group + "," + Name1 + "," + LoginID2 + "," + Name2 + "," + LoginID2 + "," + Name3 + "," + LoginID3 + "," + Name4 + "," + LoginID4 + "," + URL + "," + Title2 + "," + date + ")";
     PreparedStatement pstmt = null;
     try{
LINE69     pstmt = con.prepareStatement(INSERT);
     pstmt.executeUpdate();
     catch (SQLException e) {
     throw new ServletException(e);
     finally {
     try {
     if (pstmt != null)pstmt.close();
     catch (SQLException ignored){
Can you please recomend a solution to my problem.
If i mange to overcome the bug do you have any suggestions upon connection pooling or anythink that will make it to run smoothly?
Thank you for your time.

Answer 1

This is not how u use preparedStatement. You need to read the documents.
Moreover what are you going to do with the alpahanumeric fields in your database, Dont you have to encode them in codes.
When you insert the value for a field which is a string you have to enclose it with codes