please put the following code in the onsubmit method of your controller,
The framework is designed in such a way that it removes the form object from the session whenever there is a form submission.
protected ModelAndView onSubmit(
// basically you are enriching the command object from the file object //that you have recieved.
// after calling the method that returns you the enriched command object
ReportCommand reportCommand = crearReportCommandConDatosRequest(file);
// add this line of code
ModelAndView mv = new ModelAndView("viewname",getCommandName(),reportCommand);