文件夹权限需要修改 http://wenku.baidu.com/link?url=of9IhsznB_YBbIuUjbjUe6JVNT-V2PwPqKqR0ujMy3xqIwzrf6oAcnB0e_o0Q811p1mspZyOOuR9Zrf_xW2u83jnOUb_3qXqOgbwIx0cySK