用Springboot实现文件下载功能

 ApiOperation(value = "下载文件", httpMethod = "GET", notes = "downloadFile", response = String.class)
     public String downloadFile(HttpServletRequest request, HttpServletResponse response) {
        String fileName = "zabbix.txt";// 设置文件名
             if (fileName != null) {
                 //设置文件路径
                // String realPath = "D://zabbix_agentd.conf";
                 String realPath = "D:" + File.separator + "zabbix_agentd.conf";
                 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);
                         }
                         System.out.println("success");

                         InetAddress addr = InetAddress.getLocalHost();
                         String ip=addr.getHostAddress(); //获取本机ip
                         replacTextContent(ip);
                     } catch (Exception e) {
                         e.printStackTrace();
                     } finally {
                         if (bis != null) {
                             try {
                                 bis.close();
                             } catch (IOException e) {
                                 e.printStackTrace();
                             }
                         }
                         if (fis != null) {
                             try {
                                 fis.close();
                             } catch (IOException e) {
                                 e.printStackTrace();
                             }
                         }
                     }
                 }
             }
             return null;
     }
     /**
      * 替换文本文件中的 指定字符串
      * @param path
      * @throws IOException
      */
     public void replacTextContent(String ip){
         try {
             File file = new File("D:zabbix_agentd.conf");
             String content = FileUtils.readFileToString(file, "utf-8");
             //原有的内容
             String srcStr = "Hostname=192.168.1.177";
             //要替换的内容
             String replaceStr ="Hostname"+ ip;
             // 读
             FileReader in = new FileReader(content);
             BufferedReader bufIn = new BufferedReader(in);
             // 内存流, 作为临时流
             CharArrayWriter  tempStream = new CharArrayWriter();
             // 替换
             String line = null;
             while ( (line = bufIn.readLine()) != null) {
                 // 替换每行中, 符合条件的字符串
                 line = line.replaceAll(srcStr, replaceStr);
                 // 将该行写入内存
                 tempStream.write(line);
                 // 添加换行符
                 tempStream.append(System.getProperty("line.separator"));
             }
             // 关闭 输入流
             bufIn.close();
             // 将内存中的流 写入 文件
             FileWriter out = new FileWriter(file);
             tempStream.writeTo(out);
             out.close();
         }catch (Exception e) {
             e.printStackTrace();
         }
     }