POI 火狐下载文件-中文文件名乱码

fileName = new String((fileName).getBytes(" UTF-8"), "ISO8859_1")+Dates.formatDateTime_New(new Date());

response.setContentType("application/vnd.ms-excel");

response.setHeader("Content-disposition", "attachment;filename=" + fileName.replace(" ", "_") + ".xls");

UTF-8文件名正常显示，gb2312中文乱码，所以要用UTF-8