FTP服务器的上传与下载

た入场券 2022-09-30 06:27 261阅读 0赞

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# 前言 #

这是前三周的事情了，拿到现在来总结真是惭愧了，某个周四把任务都做完了，看了会代码有点乏了，就开始鼓捣，想起来自己对数据库的语句操作一直不是很熟悉，所以就找了个教程敲了一遍操作语句，估计是组长看我没事了，周五给我安排了个任务，将文件从CDN服务器上down下来，上传到Preview服务器的对应目录下。下面记录一下我在本地测试的内容。

# FTP服务简介 #

FTP全称File Transfer Protocol，文件传输协议，是TCP/IP协议组中的协议之一，FTP协议分为两部分：FTP服务器和FTP客户端，我们都已经知道了文件传输用到的端口为20和21。FTP服务器的默认端口是21,FTP 客户端首先和FTP服务器的TCP 21端口建立连接，通过这个通道发送命令，客户端需要接收数据的时候在这个通道上发送PORT命令。 PORT命令包含了客户端用什么端口接收数据。在传送数据的时候，服务器端通过自己的TCP 20端口连接至客户端的指定端口发送数据。有个简单的实例就是大米用的管理资料的服务器，这个服务器担当的是服务器端的角色，而我们用的电脑担当则是客户端的角色。

# 功能实现 #

1.准备本地测试的工具：FTPserver

![Center][]

2.把本地模拟成服务端，端口为21，用户名为anonymous，密码为\*\*\*\*，左下角的即为当前的IP地址，这些信息用于对用户授权，我们操作FTP服务器都是需要授权的，格式为：ftp://用户名：密码@FTP服务器IP或域名：FTP命令端口/路径/文件名。

3.准备FTPHelper，封装上传与下载的代码

public class FTPHelper
        {
            #region Variables
    
            private FtpWebRequest reqFTP = null;
    
            private string userName { get; set; }
    
            private string password { get; set; }
    
            //private string ftpUri { get; set; }
    
            private NetworkCredential certficate;
    
            public FtpStatusCode statusCode { get; set; }
    
            public string statusDescription { get; set; }
    
            #endregion
    
            #region Constructor
    
            public FTPHelper(string ftpUserName, string ftpPassword)
            {
                this.userName = ftpUserName;
                this.password = ftpPassword;
                certficate = new NetworkCredential(ftpUserName, ftpPassword);
            }
    
            #endregion
    
            #region UploadOverMove
    
            public bool UploadOverMove(string ftpRootDirectory, string sourceFilePath, string storedFilePath, string storedFileName, ref string errMessage)
            {
                FileInfo fileInfo = new FileInfo(sourceFilePath);
                Uri uri = new Uri(storedFilePath);
                string remoteDirectory = storedFilePath.Remove(0, ftpRootDirectory.Length);
                remoteDirectory = remoteDirectory.Substring(0, remoteDirectory.Length - storedFileName.Length);
    
                try
                {
                    CreateDirectory(ftpRootDirectory, remoteDirectory);
    
                    FtpWebRequest reqFTP = CreateFtpRequest(uri, WebRequestMethods.Ftp.UploadFile);
                    reqFTP.ContentLength = fileInfo.Length;
    
                    int buffLength = 2048;
                    byte[] buff = new byte[buffLength];
                    int contentLen;
    
                    FileStream fs = fileInfo.OpenRead();
                    Stream strm = reqFTP.GetRequestStream();
                    contentLen = fs.Read(buff, 0, buffLength);
    
                    while (contentLen != 0)
                    {
                        strm.Write(buff, 0, contentLen);
                        contentLen = fs.Read(buff, 0, buffLength);
                    }
    
                    strm.Close();
                    fs.Close();
                    return true;
                }
                catch (Exception ex)
                {
                    errMessage = ex.Message;
                }
    
                return false;
            }
    
            #endregion
    
            #region DownloadFile
    
            public bool DownloadFile(string remoteFilePath, string localFilePath, ref string errMessage)
            {
                try
                {
                    string localDirector = Path.GetDirectoryName(localFilePath);
                    if (!Directory.Exists(localDirector))
                    {
                        Directory.CreateDirectory(localDirector);
                    }
    
                    FtpWebResponse response = CreateFtpResponse(new Uri(remoteFilePath), WebRequestMethods.Ftp.DownloadFile);
                    byte[] buffer = new byte[2048];
                    int bytesCount = 0;
                    Stream stream = response.GetResponseStream();
                    using (FileStream fs = new FileStream(localFilePath, FileMode.Create))
                    {
                        while ((bytesCount = stream.Read(buffer, 0, buffer.Length)) > 0)
                        {
                            fs.Write(buffer, 0, bytesCount);
                        }
                    }
                    return true;
                }
                catch (Exception ex)
                {
                    errMessage = ex.Message;
                }
                return false;
            }
    
            #endregion
    
            #region DirectoryExist
    
            private bool DirectoryExist(string ftpDirectory)
            {
                List<string> list = GetDirectoryList(ftpDirectory);
    
                if (list != null)
                {
                    return true;
                }
    
                return false;
            }
            #endregion
    
            #region Create Directory
    
            public void CreateDirectory(string ftpUri, string remoteDirectory)
            {
                this.statusDescription = ftpUri;
                string parentDirector = ftpUri;
    
                try
                {
                    if (!string.IsNullOrEmpty(remoteDirectory))
                    {
                        remoteDirectory = remoteDirectory.Replace("\\", "/");
                        string[] directors = remoteDirectory.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);
    
                        foreach (string director in directors)
                        {
                            parentDirector = string.Concat(parentDirector, director);
                            this.statusDescription = parentDirector;
    
    
                            if (!DirectoryExist(parentDirector))
                            {
                                CreateFtpResponse(new Uri(parentDirector), WebRequestMethods.Ftp.MakeDirectory);
                            }
    
                            parentDirector = string.Concat(parentDirector, "/");
                        }
                    }
                }
                catch (WebException ex)
                {
                    statusDescription = ex.Message;
                    throw ex;
                }
            }
    
            #endregion
    
            #region CreateFtpWebRequest
    
            private FtpWebRequest CreateFtpRequest(Uri uri, string method)
            {
                reqFTP = (FtpWebRequest)WebRequest.Create(uri);
                reqFTP.Proxy = null;
                reqFTP.Credentials = new NetworkCredential(userName, password);
                reqFTP.KeepAlive = true;
                reqFTP.UseBinary = true;
                reqFTP.UsePassive = true;
                reqFTP.Method = method;
                reqFTP.UsePassive = true;
                return reqFTP;
            }
    
            #endregion
    
            #region CreateFtpResponse
    
            private FtpWebResponse CreateFtpResponse(Uri uri, string method)
            {
                try
                {
                    FtpWebRequest request = CreateFtpRequest(uri, method);
                    FtpWebResponse response = (FtpWebResponse)request.GetResponse();
                    this.statusCode = response.StatusCode;
                    this.statusDescription = response.StatusDescription;
                    return response;
                }
                catch (WebException ex)
                {
                    FtpWebResponse response = ex.Response as FtpWebResponse;
                    if (response != null)
                    {
                        this.statusCode = response.StatusCode;
                        this.statusDescription = response.StatusDescription;
                    }
                    throw ex;
                }
            }
    
            #endregion
    
            #region GetDirectoryList
    
            private List<string> GetDirectoryList(string ftpDirectory)
            {
                List<string> ftpRawList = new List<string>();
                StringBuilder result = new StringBuilder();
    
                FtpWebRequest request = (FtpWebRequest)WebRequest.Create(new Uri(ftpDirectory));
                request.Timeout = 60000;
                request.ReadWriteTimeout = 60000;
                request.Credentials = this.certficate;
                request.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
                try
                {
                using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())
                {
                    Stream data = response.GetResponseStream();
    
                    using (StreamReader reader = new StreamReader(data))
                    {
                        string responseString = reader.ReadToEnd();
                        reader.Close();
                        response.Close();
    
                        ftpRawList.AddRange(result.ToString().Split(new char[2] { '\r', '\n' }, StringSplitOptions.RemoveEmptyEntries));
    
                        return ftpRawList;
                    }
                }
                }
                catch (Exception ex)
                {
                    return null;
                }
            }
    
            #endregion
        }

4.编写上传文件代码（由上图中的FTPServer知，访问的路径为E盘）

string localPath = "D:/ftp/test.txt"; //需要上传的文件
    string ftpPath = "ftp://10.96.206.157:21/UploadFile/";  //上传的数据，上传的路径
    FTPHelper ftpHelper = new FTPHelper("anonymous", "your password");
    var isUpload = ftpHelper.UploadOverMove(ftpPath, localPath, ftpPath, FileName, ref errMessage);

5.编写下载文件代码

string localPath = "D:/ftp/DownLoadFile"; //下载下来的文件存放路径
    string ftpPath = "ftp://10.96.206.157:21/UploadFile/test.txt";  //需要下载的文件
    FTPHelper ftpHelper = new FTPHelper("anonymous", "your password");
    string errMessage = "";
    var isDownload = ftpHelper.DownloadFile(ftpfilePath, localFilePath, ref errMessage);

6.模拟向服务器上传文件，FTPserver选择上传文件，开启服务。在本地D:/ftp路径下建立一个test.txt文件,运行上传文件的代码，会看到我们将test.txt文件从D盘上传到了E:/UploadFile路径下。

7.模拟从服务器下载文件，FTPserver选择下载文件，开启服务。运行下载文件的代码，将刚才上传的文件下载到D:/ftp/DownLoadFile路径下。

# 总结 #

好玩的事情挺多的，自己多去玩玩吧！

[http_www.captainbed.net_zhanghan]: http://www.captainbed.net/zhanghan
[Center]: /images/20220708/ef44fb5e8ef94f19a184e7d508181be9.png