Http和FTP下载文件

Posted 2021-05-26 胖虎嘟嘟

说起下载文件，大家都会想起http和FTP下载。http和ftp，其实底层都是基于socket通信，只不过http和ftp协议格式定义不一样而已。
下载文件，要看服务器支持什么类型的协议，如果只支持http，那你就用httpwebrequest类好了，如果支持FTP，那你就用FTP的类来下载文件。

下面是我对两者的总结使用。

http:

        /// <summary>下载安装包</summary>
        public void downloadPack(string macCode ,string appType,string address)
        {
           
            StringBuilder data = new StringBuilder();
            data.Append("{\\"cpu\\":\\"" + macCode + "\\"");     
            data.Append(",\\"appType\\":\\"" + appType + "\\"}");
            //data.Append(",\\"softwareVersion\\":\\"" + iniFile.IniReadValue("USER", "versionNo") + "\\"");
            ServicePointManager.ServerCertificateValidationCallback = ValidateServerCertificate;
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(address);
            request.Headers.Add("X-Auth-Token", HttpUtility.UrlEncode("openstack"));
            request.Method = "POST";

            request.ContentType = "application/json";
            request.Accept = "application/json";
            byte[] byteData = Encoding.UTF8.GetBytes(data.ToString());
//把要下载的http的文件的相关信息告诉后台
            using (Stream postStream = request.GetRequestStream())
            {
                postStream.Write(byteData, 0, byteData.Length);
            }
            Log.AddLog("Download", "2");
            sc.start();
            process = 0;
            using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
            {
                Log.AddLog("Download", "3");
                int all_count = 0;
                using (Stream reader = response.GetResponseStream())
                {
                    Log.AddLog("Download", filePath);
                    using (FileStream fw = new FileStream(filePath, FileMode.Create, FileAccess.Write))
                    {
                        Log.AddLog("Download", "5");
                        byte[] buffer = new byte[1024 * 10];
                        while (true)
                        {
                            Log.AddLog("Download", all_count.ToString());
                            int count = reader.Read(buffer, 0, buffer.Length);
                            all_count += count;
                            fw.Write(buffer, 0, count);
                            sc.setSize(all_count);
                            writeCount += (ulong)count;
                            process = (float)writeCount / (float)fileSize;
                            
                            if (count <= 0)
                            {
                                break;
                            }
                        }
                        isFinish = true;
                        sc.stop();
                    }
                }

            }
        }

 

 

 

FTP：

       static string downloadFile(string fileName)
        {
           
            string error = "";
            int sumSize = 0;
            process = 0;
            //下载后的文件存放路径
            string downloadUrl = getBasePath() + fileName;
            //需要现在的文件在ftp上的完整路径
            string fileUploadPath = ftpServer + fileName;
            Uri uri = new Uri(fileUploadPath);
            //创建文件流
            FileStream fs = null;
            Stream responseStream = null;
            try
            {
                //创建一个与FTP服务器联系的FtpWebRequest对象
                FtpWebRequest request = (FtpWebRequest)WebRequest.Create(uri);
                //设置请求的方法是FTP文件下载
                request.Method = WebRequestMethods.Ftp.DownloadFile;
                //连接登录FTP服务器
                request.Credentials = new NetworkCredential(ftpUserName, ftpUserPwd);
                //获取一个请求响应对象
                FtpWebResponse response = (FtpWebResponse)request.GetResponse();
                //获取请求的响应流
                responseStream = response.GetResponseStream();
                //判断本地文件是否存在，如果存在，则打开和重写本地文件
                if (File.Exists(downloadUrl))
                {
                    fs = File.Open(downloadUrl, FileMode.Open, FileAccess.ReadWrite);
                }
                else
                {
                    fs = File.Create(downloadUrl);
                }

                if (fs != null)
                {
                    int buffer_count = 65536;
                    byte[] buffer = new byte[buffer_count];
                    int size = 0;
                    while ((size = responseStream.Read(buffer, 0, buffer_count)) > 0)
                    {
                        fs.Write(buffer, 0, size);
                        sumSize += size;
                        process = sumSize * 1.0 / allSize;
                       
                    }
                    fs.Flush();
                    fs.Close();
                    responseStream.Close();
                }
            }
            catch(Exception e)
            {
              
                error = "自动更新服务异常：" + e.ToString();
            }
            finally
            {
                if (fs != null)
                    fs.Close();
                if (responseStream != null)
                    responseStream.Close();  
            }
          
            return null;
        }