how to have many objects or models in one form with spring mvc - spring

Question

i have to use one form for two modelAttributes : "groupes" which is a list of Groupe and "matieres" is a list of Matiere, i know that one form support only one modelAttribute , i tried two options but both doesn't work,one by using spring bind tag and the other one by wrapping groupes and matieres in one class,
Any ideas how to solve this ?
#RequestMapping(method = RequestMethod.GET)
public ModelAndView showForm() {
ModelAndView mv = new ModelAndView("abs");
mv.addObject("matiere", matiereservice.findAlmatieres());
mv.addObject("groupe", groupeservice.findAllGroupes());
return mv;
}
#RequestMapping( method = RequestMethod.POST)
public String submitForm( #ModelAttribute("groupe") Groupe groupe, #ModelAttribute("matiere") Matiere matiere,
ModelMap map,
BindingResult result
) {
// BindingResult treatment
return "listeleve" ;
}

Answer 1

Instead of sending those attributes separately, simply make a DTO class which contains List fields of both of your Groupe and Matiere classes.
public class ListeleveDTO {
private List<Groupe> groupe;
private List<Matiere> matiere;
public ListeleveDTO(List<Groupe> groupe, List<Matiere> matiere) {
// Assign to fields
}
// getters and setters
}
And set the instance of this class as a model attribute.
#RequestMapping(method = RequestMethod.GET)
public ModelAndView showForm() {
ModelAndView mv = new ModelAndView("abs");
mv.addObject("listeleveDTO", new ListeleveDTO(groupeservice.findAllGroupes(), matiereservice.findAlmatieres());
return mv;
}
#RequestMapping( method = RequestMethod.POST)
public String submitForm( #ModelAttribute("listeleveDTO") ListeleveDTO,
ModelMap map,
BindingResult result
) {
// BindingResult treatment
return "listeleve" ;
}