java中List>关于null的判断

List<Map<String, Object>> selectTmFileInfo = fileInfoService.selectTmFileInfoByToken(cToken);

Map<String, Object> fileMapFileId = selectTmFileInfo.get(0);

if(CollectionUtils.isEmpty(fileMapFileId)){    //相当于 fileMapFileId == null || fileMapFileId .isEmpty()

       为空
}