public ArrayList<String> traerListado(int codEdif){
    conn = Conector.conectorBd();  
    String sql = "select distinct d.n_dpto as numeroDepto, l.pago as monto, l.fecha from lavanderia l, departamento d, edificio e where l.coddepto=d.id_dpto and d.codedi=e.cod_ed and e.cod_ed\n" +
"="+codEdif+"";           
        try {
            pst = conn.prepareStatement(sql);
            
            ArrayList<String> ls = new ArrayList<String>();
            
            rs = pst.executeQuery();
            while(rs.next()){
            
                ls.add(String.valueOf(rs.getInt("numerodepto")));
                ls.add(String.valueOf(rs.getInt("monto")));
                ls.add(String.valueOf(rs.getDate("fecha")));
            }
            return ls;
            
        } catch (Exception e) {
            return null;
        }
    
    }