java 文件下載 解決中文問題

@RequestMapping(value="/download")
 public @ResponseBody String download(HttpServletResponse response,HttpServletRequest request,@Param(value="filePath") String filePath,@Param(value="")String id ) {
        try {
          NjWorkLog njWorkLog= njWorkLogService.findOneById(id);
            // path是指欲下載的文件的路徑。
            File file = new File(request.getRealPath(filePath));
            // 取得文件名。
            //String filename = file.getName();
            // 取得文件的後綴名。
           // String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();
            // 以流的形式下載文件。
            InputStream fis = new BufferedInputStream(new FileInputStream(file.getPath()));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();
            // 清空response
            response.reset();
            // 設置response的Header
            String filename=njWorkLog.getStrFileName();
            if (request.getHeader("User-Agent").toUpperCase().indexOf("MSIE") > 0)
             filename = URLEncoder.encode(filename, "UTF-8");//IE瀏覽器
            if (request.getHeader("User-Agent").toLowerCase().indexOf("firefox") > 0)
             filename = new String(filename.getBytes("UTF-8"), "ISO8859-1");//firefox瀏覽器
            response.addHeader("content-type","application/octet-stream");
            response.addHeader("Content-Disposition","attachment;filename="+filename);
            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
            toClient.write(buffer);
            toClient.flush();
            toClient.close();
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return "";
    }