文件的下载与跨域问题的解决

@RequestMapping(value = "downExcle", method = RequestMethod.GET)
@ResponseBody
public  void  downLoadExcle(@RequestParam String uuid,HttpServletResponse response) {
    try {
        // path是指欲下载的文件的路径。
        Map map = new HashMap();
        map.put("id", uuid);
        String filePath = filePathService.queryFilePathById(map);
        File file = new File(filePath);
        if (!file.exists()) {
            response.sendError(404, "File not found!");
        } else {
            // 取得文件名。
            String filename = file.getName();

            // 以流的形式下载文件。
            InputStream fis = new BufferedInputStream(new FileInputStream(filePath));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();


            // 清空response
            // JSONP 解决跨域问题
            response.reset();
            response.addHeader("Access-Control-Allow-Origin", "*");
            response.addHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE");
            response.addHeader("Access-Control-Allow-Headers", "Content-Type");
            // 设置response的Header
            response.setHeader("Content-Disposition", "attachment;filename="
                    + new String(filename.getBytes(),"iso-8859-1"));
            response.addHeader("Content-Length", "" + file.length());
            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");

           //http://www.ruanyifeng.com/blog/2016/04/cors.html 跨域详情介绍

            toClient.write(buffer);
            toClient.flush();
            toClient.close();
        }
    } catch (IOException ex) {
        ex.printStackTrace();
    }