Error description:
There was an unexpected error (type=Internal Server Error, status=500).
Cannot invoke "com.example.produits.service.StabiliteService.saveStabilite(com.example.produits.entities.Stabilite)" because "this.stabiliteService" is null
java.lang.NullPointerException: Cannot invoke "com.example.produits.service.StabiliteService.saveStabilite(com.example.produits.entities.Stabilite)" because "this.stabiliteService" is null
controller class
@Controller
public class StabiliteController {
    @Autowired(required = false)
    private StabiliteService stabiliteService;
    @RequestMapping("/createStabilite")
    public String createStabilite(ModelMap modelMap) {
        modelMap.addAttribute("stabilite", new Stabilite());
        modelMap.addAttribute("mode", "new");
        return "formStabilite";
    }
    @RequestMapping("/saveStabilite")
    public String saveStabilite(@Valid Stabilite stabilite, BindingResult bindingResult) {
        if (bindingResult.hasErrors())
            return "formStabilite";
        stabiliteService.saveStabilite(stabilite);
        return "formStabilite";
    }
service class:
@Service
public interface StabiliteService {
    Stabilite saveStabilite(Stabilite s);
    Stabilite updateStabilite(Stabilite s);
    void deleteStabilite(Stabilite s);
    void deleteStabiliteById(Long id);
    Stabilite getStabilite(Long id);
    List<Stabilite> getAllStabilites();
    List<Stabilite> findByLibelleStabilite(String libelle);
    Page<Stabilite> getAllStabillitesParPage(int page, int size);
}
 
     
    