Salve,
in primis complimenti per la community di supporto. Veniamo al dunque:
Per esercitarmi ho deciso di realizzare un blog utilizzando servlet e pagine JSP. Ecco i sorgenti della jsp per inserire dei post e la relativa servlet di comunicazione al DB.
codice:
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
   "http://www.w3.org/TR/html4/loose.dtd">

<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
        <link rel="stylesheet" type="text/css" href="form.css"/>
    </head>
    <body>
        <h2 align="center">Login</h2>
<form id="form1" name="form1" method="post" action="chiamaServlet">

  <label><div class="username">Username</div>
  <div class="input"><input name="username" type="text" id="username" maxlength="50" /></div>
  <div class="break"></div>
  </label>
  <label><div class="username">Password</div>
  <div class="input"><input name="password" type="password" id="password" maxlength="50" /></div>
  </label>
  <div class="break"></div>
<p align="center">
  <input class="invia" type="submit" name="button" id="button" value="Invia" />

</form>
    </body>
</html>
codice:
/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

package blog;

import java.io.IOException;
import java.io.PrintWriter;
/*import java.util.*;*/
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.text.*;
import java.sql.*;
import java.util.Calendar;
import java.util.GregorianCalendar;

/**
 *
 * @author Francesco
 */
public class inserisciCommento extends HttpServlet {
    private DataAccess connection;
    
    @Override
    public void init() throws ServletException {
    super.init();
    connection=DataAccess.newDataAccess();
    }





    /** 
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException, SQLException, ParseException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        try {
            //ricevo i dati in input e li immagazzino in stringhe
            String autore = request.getParameter("autore");
            String titolo = request.getParameter("titolo");
            String articolo = request.getParameter("articolo");

                   
            GregorianCalendar gc= new GregorianCalendar();
            Date d =  (Date) gc.getTime();
            SimpleDateFormat sdf= new SimpleDateFormat("dd-MM-yyyy");
            String data= sdf.format(d);
            out.println(data);
            Calendar ctoDay = Calendar.getInstance();
            java.sql.Date oggi = new java.sql.Date((ctoDay.getTime()).getTime()); // data odierna.
           
               

            PreparedStatement pst = null;
            pst = connection.prepareStatement("INSERT INTO articoli  (art_autore,art_titolo,art_articolo,art_data) VALUES ((?),(?),(?),(?))");
            pst.setString(1, autore);
            pst.setString(2,titolo);
            pst.setString(3,articolo);
            pst.setDate(4,oggi);
            pst.executeUpdate();
            pst.close();
                            
            
            /* TODO output your page here
            out.println("<html>");
            out.println("<head>");
            out.println("<title>Servlet inserisciCommento</title>");  
            out.println("</head>");
            out.println("<body>");
            out.println("<h1>Servlet inserisciCommento at " + request.getContextPath () + "</h1>");
            out.println("</body>");
            out.println("</html>");
            */
        } finally { 
            out.close();
        }
    } 

    // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">
    /** 
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        try {
            try {
                processRequest(request, response);
            } catch (ParseException ex) {
                Logger.getLogger(inserisciCommento.class.getName()).log(Level.SEVERE, null, ex);
            }
        } catch (SQLException ex) {
            Logger.getLogger(inserisciCommento.class.getName()).log(Level.SEVERE, null, ex);
        }
    } 

    /** 
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException {
        try {
            try {
                processRequest(request, response);
            } catch (ParseException ex) {
                Logger.getLogger(inserisciCommento.class.getName()).log(Level.SEVERE, null, ex);
            }
        } catch (SQLException ex) {
            Logger.getLogger(inserisciCommento.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    /** 
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}
Ed ecco la servlet che si occupa della connessione al DB

codice:
package blog;

    

    import com.mysql.jdbc.Connection;
    import java.sql.*;
    import javax.servlet.ServletException;

    /**
    *
    * @author katone
    */

    public class DataAccess {

    //Creazione singleton
    private static DataAccess connessione = null;

    public synchronized static DataAccess newDataAccess() throws ServletException {
    if (connessione == null) connessione = new DataAccess();
    return connessione;
    }
    private Connection c = null;

    public ResultSet GenericQuery(String _sql){
        Statement s = null;
        ResultSet r;
        try{
        s = (Statement) c.createStatement();
        r = s.executeQuery(_sql);
        return r;
        }
        catch (SQLException e) {
        e.printStackTrace();
        return null;
        }
    }

    //costruttore privato della classe DataAccess
    private DataAccess() throws ServletException {
    try {
    Class.forName("com.mysql.jdbc.Driver");
    String url = ("jdbc:mysql://localhost/blog");
    String user = ("root");
    String pass = ("francesco");
    c = (Connection) DriverManager.getConnection(url, user, pass);
    }catch(ClassNotFoundException e) {
    e.printStackTrace();
    throw new ServletException("Errore di caricamento driver database",e);
    } catch(SQLException e) {
    e.printStackTrace();
    throw new ServletException("Errore di connessione al database",e);
    }
    }

    //Chiusura della connesione col db
    @Override
    protected void finalize() throws Throwable {
    super.finalize();
    if (c!=null) c.close();
    }

    PreparedStatement prepareStatement(String string) {
        throw new UnsupportedOperationException("Not yet implemented");
    }

    }


Purtroppo, non avviene alcuna insert all'interno del DB in questione.
Vi ringrazio anticipatamente per gli eventuali aiuti e/o suggerimenti.