springboot下载txt接口

    @Override
    public void downloadKey(Long companyId) {

        CompanyInfo companyInfo = this.getById(companyId);

        if (companyInfo.getApiKey() == null || companyInfo.getPrivateKey() == null || companyInfo.getPublicKey() == null) {
            throw new ServiceException("下载失败：请先生成密钥！");
        }

        HttpServletResponse response = ServletUtil.getResponse();
        response.setCharacterEncoding("utf-8");
        //设置响应的内容类型
        response.setContentType("text/plain");
        //设置文件的名称和格式
        response.addHeader("Content-Disposition", "attachment;filename=key.txt");
　　　　　// 在try的括号中引用的资源可以自动关闭，不需要buff.close()
        try (
                ServletOutputStream outStr = response.getOutputStream();
                BufferedOutputStream buff = new BufferedOutputStream(outStr)
        ) {
            String text = "ApiKey:" + companyInfo.getApiKey() + "\n";
            text += "-----BEGIN PRIVATE KEY-----\n" + companyInfo.getPrivateKey() + "\n-----END PRIVATE KEY-----";
            buff.write(text.getBytes("UTF-8"));
            buff.flush();
        } catch (Exception e) {
           e.printStackTrace();
        }
    }