计算传递的servlet的数量

Question

 /*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

    import java.io.IOException;
    import java.io.PrintWriter;
    import javax.servlet.RequestDispatcher;
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;

    /**
     *
     * @author neil
     */
    public class No1 extends HttpServlet {

        /**
     * 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 {
            response.setContentType("text/html;charset=UTF-8");
            PrintWriter out = response.getWriter();
            try {
                /* This is how my No1 servlet looks like*/
            /*I used the textbox name as number in html form*/
            String let = request.getParameter("number");
            /*Convert thw string to integer and assign to num variable*/
            int num = Integer.parseInt(let);

            RequestDispatcher dispatcher=request.getRequestDispatcher("No2");
            dispatcher.forward(request, response);


        }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 {
        processRequest(request, response);
    }

    /**
     * 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 {
        processRequest(request, response);
    }

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

我创建了4个servlet，分别为No1，No2，No3，No4。然后在运行文件时，它会显示一个带有文本框的JSP页面，以插入像No1，No2 ...这样的servlet名称。每个servlet页面都使用调度程序转发到下一页。所以No1 servlet转发到No2，No2转发到No3，No3转发到No4。如果我在文本框中输入No1，我想将答案显示为4，如果输入No2则应显示3.这是传递servlet的数量，我尝试使用for循环，但它不起作用，请你帮助我。