文件夹操作工具类，支持：按照特定的格式创建路径文件夹、判断文件夹是否存在、清空所有子目录、拷贝文件夹的内容、获取文件夹下的所有文件大小 -Tools folder operation and support: In accordance with the specific format to create a folder path to determine the existence of the folder, emptied all subdirectories, copy the c