java查询排序list不能为空

实习生碰到一个问题 查询排序list不能为空 我该如何去修改下面的代码

```java
/**
     * 分页列表查询
     *
     * @param gallery
     * @param pageNo
     * @param pageSize
     * @param req
     * @return
     */
    @AutoLog(value = "橱窗管理-分页列表查询")
    @ApiOperation(value="橱窗管理-分页列表查询", notes="橱窗管理-分页列表查询")
    @GetMapping(value = "/list")
    public Result queryPageList(Gallery gallery,
                                   @RequestParam(name="pageNo", defaultValue="1") Integer pageNo,
                                   @RequestParam(name="pageSize", defaultValue="10") Integer pageSize,
                                   HttpServletRequest req) {
        QueryWrapper queryWrapper = QueryGenerator.initQueryWrapper(gallery, req.getParameterMap());
        Page page = new Page(pageNo, pageSize);
        IPage pageList = galleryService.page(page, queryWrapper);
        return Result.OK(pageList);
    }

```


  @AutoLog(value = "橱窗管理-分页列表查询")
    @ApiOperation(value="橱窗管理-分页列表查询", notes="橱窗管理-分页列表查询")
    @GetMapping(value = "/list")
    public Result<?> queryPageList(Gallery gallery,
                                   @RequestParam(name="pageNo", defaultValue="1") Integer pageNo,
                                   @RequestParam(name="pageSize", defaultValue="10") Integer pageSize,
                                   HttpServletRequest req) {
        QueryWrapper<Gallery> queryWrapper = QueryGenerator.initQueryWrapper(gallery, req.getParameterMap());
        Page<Gallery> page = new Page<Gallery>(pageNo, pageSize);
        IPage<Gallery> pageList = galleryService.page(page, queryWrapper);
        List<Gallery> list = pageList.getRecords();
        if (list != null && list.size() > 0) {
          // list 不为null

        }else {
          // list为null
}
        return Result.OK(pageList);
    }

判断pageList是否为null，如果为null就new一个空的喽。