GetParameter not working in my function?

Question

hi ! I have this function but seems that the getparameter in not working and least its not catching anything.
public void facturando(HttpServletRequest request,HttpServletResponse response){
      try{
  HttpSession sesion = request.getSession(true);    
  HashMap respuesta = null;
  RequestDispatcher dispatcher = null; 
  String sDNI=null;
  BeanBDFactura bBDFac = null;
  bBDFac = new BeanBDFactura();
  System.out.println("ESTOY facturando");
       String nombre=request.getParameter("nombre"); //en realidad es nombre + apellido
       String fecha=request.getParameter("fecha");
       double totalservicios=Double.parseDouble(request.getParameter("servicios"));
       int descuento=Integer.parseInt(request.getParameter("descuento"));
       double IVA=Double.parseDouble(request.getParameter("IVA"));
       double total=Double.parseDouble(request.getParameter("total"));
       System.out.println("Datos de registrar la factura");
       System.out.println("Nombre: "+nombre);       
       System.out.println("Fecha: "+fecha);
       System.out.println("Servicios: " +totalservicios);
       System.out.println("IVA: " +IVA);
       System.out.println("Total: " +total);
       bBDFac.registrafactura(nombre,sDNI,fecha,totalservicios,descuento,IVA,total);
       RequestDispatcher rd=getServletContext().getRequestDispatcher("/exito.jsp");
       rd.forward(request,response);
     catch(Throwable theException)
  }When I execute this I get a blank page and it stops before the
System.out.println("Datos de registrar la factura");
So its a problem with getparameter. What could be causing it ?
Thanks!

Answer 1

With problems like this you have to query even your base assumptions.
request.getParameter() is returning null.
There could be any number of reasons for this - no parameters passed, parameter mis-spelled etc etc
So back to basics
1 - in your servlet print out all the parameters and their values
  Map params = request.getParameterMap();
  for(Iterator it = params.entrySet().iterator(); it.hasNext(); ){
    Map.Entry me = (Map.Entry)it.next();
    String param = (String)me.getKey();
    String[] values = (String[]) me.getValue();
    System.out.println(param + " = " + values[0]);
  }That will show you all the parameters getting to your servlet.
If there are no parameters, check how you are invoking the servlet. Via a url or a form submission?
If there ARE parameters, is the one you want there? Is it misspelled?
Its not working, so something, somewhere is wrong.
This is the first step in finding out.