selectonemenu and dialog of primefaces

Hello everyone. I am currently experiencing a problem with prime faces which is a library of visual Java components.

The problem I am having is the following: In the login screen of my system, there is a commandButton to call a dialog that contains the form to register new users. Within this form, there is a selectOneMenu that must be loaded with the States of Brazil for the user to choose. The point is that this selectOneMenu is not loading. When I click on it, it is empty.

I want to let you know that I have tried to remove the selectOneMenu from the dialog and put it in the form of the page, but it still gives the same problem.

So, I would like to ask you for help. I am sending the codes of the main components related to the login screen

Main.xhtml (system login page)

<ui:composition template="/WEB-INF/template/LayoutMain.xhtml"
xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui"
xmlns:a="http://xmlns.jcp.org/jsf/passthrough">
<h:head>
<f:facet name="first">
    <meta name="viewport" content="width-device-width, inicial-scale=1"/>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</f:facet>  
    <title><ui:insert name="titulo">Sistema de Rastreamento de Gado</ui:insert></title>
    <h:outputScript name="locale-primefaces.js" library="js" />
    <h:outputStylesheet library="css" name="sistema.css" />
</h:head>
<ui:define name="titulo">Rastrbov</ui:define>

<ui:define name="corpo">

    <f:metadata>
        <f:viewParam name="Dummy" />
        <f:event listener="#{loginBean.preRender}" type="preRenderView"></f:event>
    </f:metadata>

    <h:form prependId="false">
        <header class="main-topbar">

                <h:link outcome="/Home">
                    <h:graphicImage library="images" name="Rastrbov.png" styleClass="rastrbovPng" />
                </h:link>

            <div style="float: right;">

                <div style="float: left; line-height: 70px; margin-right: 30px;">
                    <p:inputText size="20" id="j_username" value="#{loginBean.nome}"
                        a:placeholder="&#128231;Login" />
                </div>
                <div style="float: left; line-height: 70px; margin-right: 30px;">
                    <p:password size="20" id="j_password"
                        a:placeholder="&#128273;Senha" />
                </div>

                <div style="float: left; line-height: 70px; margin-right: 10px;">
                    <p:commandButton value="Entrar" action="#{loginBean.login}"
                        ajax="false" styleClass="botaoLogin"/>


                </div>
                <div  style="line-height: 0px; margin-right: 10px;" >
                    <p:commandLink
                        styleClass="esqSenha"
                        value="Esqueceu sua senha?"
                        onclick="PF('varDialogResetarSenha').show()" type="button" />
                </div>
            </div>


        </header>
    </h:form>


    <h:form prependId="false">
        <p:panel styleClass="cadastrese" style="width:400px">
            <p:messages id="messages" autoUpdate="true" closable="true" />
            <br />
            <br />
            <p:outputLabel value="Seja bem-vindo ao sistema RastrBov"
                style="font-weight:bold;font-size:40px" />
            <p:commandButton value="Cadastre-se" size="50"
                onclick="PF('dlgCadastrarUsuario').show()"
                styleClass="botaoCadastrar"/>
        </p:panel>

        <p:dialog header="Cadastro de usuário" widgetVar="dlgCadastrarUsuario"
        modal="true" height="400">

        <h:form id="frmCadastroUser" prependId="false">

        <p:toolbar style="margin-top: 20px">
            <p:toolbarGroup >
                <p:button value="Novo" outcome="/usuario/CadastroUsuario"
                    disabled="#{cadastroUsuarioBean.editando}" />
                    <p:commandButton value="Salvar" id="botaoSalvar"
                    action="#{cadastroUsuarioBean.salvar}" update="@form" />
            </p:toolbarGroup>

        </p:toolbar>

        <p:panel>
        <p:panelGrid columns="2" id="painel"
            style="width: 100%; margin-top: 20px" columnClasses="rotulo, campo">

            <p:outputLabel value="Estado" for="estado2" />
            <p:selectOneMenu id="estado2" style="width:52%"
                value="#{LoginBean.usuario.estado}" label="Estado"
                required="true" requiredMessage="Informe o estado de residência">
                <f:selectItem itemLabel="" noSelectionOption="true" />
                <f:selectItems value="#{LoginBean.listEstados}"
                    var="estado" itemValue="#{estado}"
                    itemLabel="#{estado.estado_sigla}" />
                <!-- <p:ajax listener="#{cadastroUsuarioBean.carregarCidades}" update="cidade" /> -->
            </p:selectOneMenu>

        </p:panelGrid>
        </p:panel>
        </h:form>
        </p:dialog>
    </h:form>
    <p:separator style="margin-top:300px" />

    <footer> </footer>

</ui:define>

In the final part of the code, I declare the dialog. Inside the dialog there is only the state selectOneMenu because I removed the other components for easy viewing.

LoginBean.java (The bean that handles the actions performed on the Main.xhtml screen)

package com.sisRastrbov.controller;

import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import javax.enterprise.context.SessionScoped;
import javax.faces.context.FacesContext;
import javax.faces.model.SelectItem;
import javax.inject.Inject;
import javax.inject.Named;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.sisRastrbov.model.Estado;
import com.sisRastrbov.model.Usuario;
import com.sisRastrbov.repository.EstadosRep;
import com.sisRastrbov.util.jsf.FacesUtil;

@Named
@SessionScoped
public class LoginBean implements Serializable {

private static final long serialVersionUID = 1L;

@Inject
private FacesContext facesContext;

@Inject
private HttpServletRequest request;

@Inject
private HttpServletResponse response;

@Inject
private EstadosRep estadosRep;

private Usuario usuario;

private String nome;

private Estado estado;

private List<SelectItem> listEstados;


public void login() throws ServletException, IOException{
    RequestDispatcher dispatcher = request.getRequestDispatcher("/j_spring_security_check");
    dispatcher.forward(request, response);

    facesContext.responseComplete();
}
public void preRender(){
    if("true".equals(request.getParameter("invalid"))){
        FacesUtil.addErrorMessage("Usuário ou senha invalido!");
    }
    System.out.println("estou carregando estados");
    listEstados = new ArrayList<SelectItem>();

    List<Estado> estados = estadosRep.raizes();

    for (Estado e : estados) {
        SelectItem item = new SelectItem();
        item.setLabel(e.getEstado_sigla());
        item.setValue(e);
        listEstados.add(item);
        System.out.println(e);
    }
    if (this.estado != null) {
        estados = estadosRep.raizes();
    }
}

public String getNome() {
    return nome;
}

public void setNome(String nome) {
    this.nome = nome;
}
public EstadosRep getEstadosRep() {
    return estadosRep;
}
public void setEstadosRep(EstadosRep estadosRep) {
    this.estadosRep = estadosRep;
}
public List<SelectItem> getListEstados() {
    return listEstados;
}
public void setListEstados(List<SelectItem> listEstados) {
    this.listEstados = listEstados;
}
public Estado getEstado() {
    return estado;
}
public void setEstado(Estado estado) {
    this.estado = estado;
}
public Usuario getUsuario() {
    return usuario;
}
public void setUsuario(Usuario usuario) {
    this.usuario = usuario;
}
}

In this bean, the key is the preRender method that is used to load the selectonemenu of states at the time that Main.xhtml is started.

package com.sisRastrbov.repository;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import javax.inject.Inject;
import javax.persistence.EntityManager;

import com.sisRastrbov.model.Estado;

public class EstadosRep implements Serializable {

private static final long serialVersionUID = 1L;

@Inject 
private EntityManager manager;

public Estado porSigla(String estado_sigla) {
    return manager.find(Estado.class, estado_sigla);
}

public List<Estado> raizes(){
    return  manager.createQuery("from Estado",Estado.class).getResultList(); 
}

public List<Estado> listarEstado() {
    List<Estado> estados = new ArrayList<Estado>();
    estados= manager.createQuery("from Estado", Estado.class).getResultList();
    return estados;
}
}

State.java (State class declaration. It is used to create the State table in the database)

package com.sisRastrbov.model;

import java.io.Serializable;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.validation.constraints.NotNull;

@Entity
@Table(name = "estado")
public class Estado implements Serializable {

private static final long serialVersionUID = 1L;

private String estado_sigla;
private String estado_nome;

@Id
@Column(nullable = false, length = 2)
public String getEstado_sigla(){
    return estado_sigla;
}

public void setEstado_sigla(String estado_sigla){
    this.estado_sigla = estado_sigla;
}

@NotNull
@Column(nullable = false, length = 50)
public String getEstado_nome(){
    return estado_nome;
}

public void setEstado_nome(String estado_nome){
    this.estado_nome = estado_nome;
}

@Override
public int hashCode() {
    final int prime = 31;
    int result = 1;
    result = prime * result + ((estado_sigla == null) ? 0 : estado_sigla.hashCode());
    return result;
}

@Override
public boolean equals(Object obj) {
    if (this == obj)
        return true;
    if (obj == null)
        return false;
    if (getClass() != obj.getClass())
        return false;
    Estado other = (Estado) obj;
    if (estado_sigla == null) {
        if (other.estado_sigla != null)
            return false;
    } else if (!estado_sigla.equals(other.estado_sigla))
        return false;
    return true;
}


}

I hope for answers and thank you all.