MybatisPlus listObjs 返回只查询一个字段类型集合

    public List getPointIotStrByProcessIds(@RequestParam List processIds){
        LambdaQueryWrapper lambdaQueryWrapper =  new QueryWrapper().lambda();
        lambdaQueryWrapper.select(Point::getIotStr);
        lambdaQueryWrapper.in(Point::getProcessId,processIds);
        Function f = (o -> o.toString()) ;
 
 
        return pointService.listObjs(lambdaQueryWrapper,f);
    }

返回的是iot_str字符串集合