/**  * 文件下载  * @Description:   * @param fileName  * @param request  * @param response  * @return  */  @RequestMapping("/download")  public String downloadFile(@RequestParam("fileName") String fileName,          HttpServletRequest request, HttpServletResponse response) {      if (fileName != null) {          String realPath = request.getServletContext().getRealPath(                    "WEB-INF/File/");          File file = new File(realPath, fileName);          if (file.exists()) {              response.setContentType("application/force-download");// 设置强制下载不打开              response.addHeader("Content-Disposition",                        "attachment;fileName=" + fileName);// 设置文件名              byte[] buffer = new byte[1024];              FileInputStream fis = null;              BufferedInputStream bis = null;              try {                  fis = new FileInputStream(file);                  bis = new BufferedInputStream(fis);                  OutputStream os = response.getOutputStream();                  int i = bis.read(buffer);                  while (i != -1) {                      os.write(buffer, 0, i);                      i = bis.read(buffer);                  }              } catch (Exception e) {                  // TODO: handle exception                  e.printStackTrace();              } finally {                  if (bis != null) {                      try {                          bis.close();                      } catch (IOException e) {                          // TODO Auto-generated catch block                          e.printStackTrace();                      }                  }                  if (fis != null) {                      try {                          fis.close();                      } catch (IOException e) {                          // TODO Auto-generated catch block                          e.printStackTrace();                      }                  }              }          }      }      return null;  }