stream流将List＜对象＞ 按对象中的两个字段分组

  @Override
    public List<CustomsClearanceOutputDto> exportVehicleDerailList(CustomsClearanceInputDto dto, HttpServletResponse response) {
        List<CustomsClearanceOutputDto> list = repository.queryCustomListDetail(dto);
        // 按MT分组
        Map<String, List<CustomsClearanceOutputDto>> map = list.stream().collect(Collectors.groupingBy(data -> format("{0}#{1}", data.getModel(), data.getType())));
        
        return null;
    }

    // 按多字段分组
    public static String format(String value, Object... paras) {
        return MessageFormat.format(value, paras);
    }