spring boot下载文件

    //下载resource文件夹下面的document文件夹下的模板
   public JsonList orderDownloadTemplate(String strJson,String token,JsonList json)
    throws Exception{
       String fn = new String("文件名.xls".getBytes("GBK"), "iso8859-1");
       String filePath =  this.getClass().getClassLoader().
       getResource("document").getPath();//获取文件路径
       filePath = filePath + "/orderStaffTemplate.xls";
       getResponse().setContentType("APPLICATION");
       getResponse().setHeader("Content-Disposition",
        "attachment; filename=" + fn);
       File file=new File(filePath);
       FileInputStream fis = new FileInputStream(file);
       byte[] bytesArray = new byte[(int) file.length()];
       fis.read(bytesArray);
       fis.close();
       getResponse().getOutputStream().write(bytesArray);
       return null;
   }