Modal form not send data to spring boot controller - spring-boot

Question

I have a view made with bootstrap modal, but this form not send data to my controller. When print data from console I have only null values. My view is following:
modal-form
My code in the frontend is:
<!-- new modal -->
<div class="modal fade" id="addModal" tabindex="-1" role="dialog"
aria-labelledby="exampleModalLabel" aria-hidden="true">
<form th:action="#{/creconocida/addNew}" method="post">
<div class="modal-dialog" role="document">
<div class="modal-content">
<div class="modal-header text-center">
<h5 class="modal-title w-100" id="exampleModalLabel">Nueva
Comunidad Reconocida</h5>
<button type="button" class="close" data-dismiss="modal"
aria-label="Close">
<span aria-hidden="true">×</span>
</button>
</div>
<div class="modal-body">
<div class="input-group mb-3">
<div class="input-group-prepend">
<span class="input-group-text" id="basic-addon1">Código
único</span>
</div>
<input type="text" class="form-control" id="codigo"
name="codigoN" aria-describedby="basic-addon3">
</div>
<div class="input-group mb-3">
<div class="input-group-prepend">
<span class="input-group-text" id="basic-addon2">Nombre</span>
</div>
<input type="text" class="form-control" id="nombre"
name="nombreN" aria-describedby="basic-addon3">
</div>
<div class="input-group mb-3">
<div class="input-group-prepend">
<span class="input-group-text" id="basic-addon3">Número
familias</span>
</div>
<input type="number" class="form-control" id="numero"
name="numeroN" aria-describedby="basic-addon3">
</div>
<div class="input-group mb-3">
<div class="input-group-prepend">
<label class="input-group-text" for="inputGroupSelect01">Nacionalidad</label>
</div>
<select class="custom-select" id="nacionalidad"
name="nacionalidadN">
<option selected>Seleccione...</option>
<option value="1">One</option>
<option value="2">Two</option>
<option value="3">Three</option>
</select>
</div>
</div>
<div class="modal-footer ">
<button type="submit" class="btn btn-primary mr-auto">Guardar</button>
<button type="button" class="btn btn-secondary"
data-dismiss="modal">Cerrar</button>
</div>
</div>
</div>
</form>
</div>
Add new method in controller
#PostMapping("/addNew")
public String addNew(ComunidadReconocida creconocida) {
System.out.println("Guardando comunidad "+creconocida.getNam_m());//get only null values
asentamientoService.addNew(creconocida);
return "redirect:/creconocida/listar";
}
I can create a new entity but I can't send the values ​​entered in the form. How could I do to capture the values ​​and pass them to the controller

Answer 1

Your problem is you are not indicates to Spring that you want a '#RequestParam'.
public String addNew(#RequestParam ComunidadReconocida creconocida)