public ArrayList<String> traerListaCargos(){
    conn = Conector.conectorBd();  
    String sql = "select descripcion from tipousuario";           
        try {
            pst = conn.prepareStatement(sql);
            
            ArrayList<String> ls = new ArrayList<>();
            
            rs = pst.executeQuery();
            while(rs.next()){
            
                ls.add(rs.getString("descripcion"));
            }
            return ls;
            
        } catch (Exception e) {
            return null;
        }
    
    }