Ecco il codice ripulito e e corretto
Codice PHP:
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, IOException, SQLException, ParseException {
        response.setContentType("text/html;charset=UTF-8");
        PrintWriter out = response.getWriter();
        Connection con = null;
        String sql = null;
        PreparedStatement inserisciCommento = null;
        try {                 
                Class.forName("com.mysql.jdbc.Driver");
        }
         catch(java.lang.ClassNotFoundException ex){
                System.err.print(ex);
         }


        try{

            String autore = request.getParameter("autore");
            String titolo = request.getParameter("titolo");
            String articolo = request.getParameter("articolo");
            String url = ("jdbc:ysql://localhost/blog");
            String usr = "root";
            String pwd = "francesco";
            con = DriverManager.getConnection(url, usr, pwd);
            sql = ("INSERT INTO articoli  (art_autore,art_titolo,art_articolo,) VALUES ((?),(?),(?))");
            inserisciCommento = con.prepareStatement(sql);
            inserisciCommento.setString(1,autore);
            inserisciCommento.setString(2,titolo);
            inserisciCommento.setString(3,articolo);
            int inserimento = inserisciCommento.executeUpdate();
            if(inserimento == 1){
                out.println("Inserimento Effettuato");
            }
            else{
                out.println("Inserimento Non Effettuato");
            }
            }
        catch(SQLException sqlexx){
            System.err.println(sqlexx.getMessage());
        }
            
            /* 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 {
             try{
                 if(inserisciCommento!= null){
                     inserisciCommento.close();
                 }
                 if(con!=null){

                     con.close();
                 }

             }
             catch(SQLException sqlexxx){
                 System.err.print(sqlexxx.getMessage());
             }
            out.close();
        } 
Niente da fare. Non funge.. suggerimenti?