public ArrayList<Administrador> getAll(){
        PreparedStatement ps;
        ArrayList<Administrador> admins = new ArrayList<>();
        try {
            ps = mycon.prepareStatement("SELECT * FROM Administradores");
            ResultSet rs = ps.executeQuery();
            if(rs!=null){
                try {
                    while(rs.next()){
                        admins.add(
                            new Administrador(
                                rs.getString("userName"), 
                                rs.getString("passwd"),
                                rs.getString("dni")
                            )
                        );
                    }
                } catch (SQLException ex) {
                    Logger.getLogger(Administrador.class.getName()).
                            log(Level.SEVERE, null, ex);
                }
            }else{
                System.out.println("Total de registros encontrados es: 0");
            }
        } catch (SQLException ex) {
            Logger.getLogger(AdministradorCRUD.class.getName()).log(Level.SEVERE, null, ex);
        }
        
        return admins;
    }