SSM 实现文件下载功能（用postman测试）

1. 前端只用传文件的路径即可。 如：String path = “D:user est.docx”;
2. controller

   @Autowired
   FileService fileService;
   /**
    * 前端传文件路径来下载文件
    *
    * @param path 文件路径，如 /guide/appendix.doc
    * @param response
    * @return
    */
   @RequestMapping(value = "/download")
   @ResponseBody
   public CommonReturnType downloadAppendix(@Param("path") String path, HttpServletRequest request, HttpServletResponse response) {
       fileService.downloadFile(path,request,response);
       return CommonReturnType.create(null, "下载完成");
   }

3. service

   @Override
   public void downloadFile(String path, HttpServletRequest request, HttpServletResponse response) {
       try {
           //String pathTest = "D:\UPC\offer"+"\"+fileName;
           //转码，免得文件名中文乱码(有时候加上反而会乱码)
           // fileName = URLEncoder.encode(fileName,"UTF-8");
   
           //从路径中获取文件名称，trim：去除字符串前后的空格
           File tempFile = new File(path.trim());
           String filename = tempFile.getName();
   
           //解决中文文件名乱码
           String userAgent = request.getHeader("User-Agent");
           //IE内核浏览器
           if (userAgent.contains("MSIE") || userAgent.contains("Trident")) {
               filename = java.net.URLEncoder.encode(filename, "UTF-8");
           } else {
               // 非IE浏览器的处理：
               filename = new String(filename.getBytes("UTF-8"), "ISO-8859-1");
           }
           //设置文件下载头
           response.setHeader("Content-disposition",String.format("attachment; filename="%s"", filename));
           //设置文件ContentType类型，这样设置，会自动判断下载文件类型
           response.setContentType("multipart/form-data");
           response.setCharacterEncoding("UTF-8");
   
           InputStream inputStream = new BufferedInputStream(new FileInputStream(new File(path)));
           BufferedOutputStream outputStream = new BufferedOutputStream(response.getOutputStream());
           //创建缓冲区
           byte[] buffer = new byte[1024];
           int length;
           while ((length = inputStream.read(buffer)) != -1) {
               outputStream.write(buffer, 0, length);
               outputStream.flush();
           }
           //关闭流
           inputStream.close();
           outputStream.close();
       } catch (IOException e) {
           e.printStackTrace();
       }
   }

4. postman测试

    本人完整调试，简单标准实现文件下载