/**
     * 设置文件名响应头
     * @param response response
     * @param request request
     * @param fileName 文件名
     * @throws UnsupportedEncodingException
     */
    private void setFileNameToResponse(HttpServletResponse response, HttpServletRequest request, String fileName) throws UnsupportedEncodingException {
        if (fileName != null){
            String userAgent = request.getHeader("User-Agent").toLowerCase();
            if(userAgent.contains("msie") || userAgent.contains("trident") || userAgent.contains("edge")){
                fileName = URLEncoder.encode(fileName, "UTF-8");
                fileName=fileName.replaceAll("\\+","%20");//处理空格展示成加号的问题
            }else{
                fileName = new String(fileName.getBytes(),"ISO8859-1");
            }
            response.setHeader("Content-disposition", String.format("attachment; filename=\"%s\"", fileName));
        }
    }