一个FTP客户端的C#代码

2022-07-15 80酷酷网 80kuku.com

　　客户端

using System;
using System.Net;
using System.IO;
using System.Text;
using System.Net.Sockets;

namespace zhangyuk.net.csdn.blog.ftpclient
{
/// <summary>
/// FTP Client
/// </summary>
public class FTPClient
{
#region 构造函数
/// <summary>
/// 缺省构造函数
/// </summary>
public FTPClient()
{
   strRemoteHost = "";
   strRemotePath = "";
   strRemoteUser = "";
   strRemotePass = "";
   strRemotePort = 21;
   bConnected     = false;
}

/// <summary>
/// 构造函数
/// </summary>
/// <param name="remoteHost"></param>
/// <param name="remotePath"></param>
/// <param name="remoteUser"></param>
/// <param name="remotePass"></param>
/// <param name="remotePort"></param>
public FTPClient( string remoteHost, string remotePath, string remoteUser, string remotePass, int remotePort )
{
   strRemoteHost = remoteHost;
   strRemotePath = remotePath;
   strRemoteUser = remoteUser;
   strRemotePass = remotePass;
   strRemotePort = remotePort;
   Connect();
}
#endregion

#region 登陆
/// <summary>
/// FTP服务器IP地址
/// </summary>
private string strRemoteHost;
public string RemoteHost
{
   get
   {
    return strRemoteHost;
   }
   set
   {
    strRemoteHost = value;
   }
}
/// <summary>
/// FTP服务器端口
/// </summary>
private int strRemotePort;
public int RemotePort
{
   get
   {
    return strRemotePort;
   }
   set
   {
    strRemotePort = value;
   }
}
/// <summary>
/// 当前服务器目录
/// </summary>
private string strRemotePath;
public string RemotePath
{
   get
   {
    return strRemotePath;
   }
   set
   {
    strRemotePath = value;
   }
}
/// <summary>
/// 登录用户账号
/// </summary>
private string strRemoteUser;
public string RemoteUser
{
   set
   {
    strRemoteUser = value;
   }
}
/// <summary>
/// 用户登录密码
/// </summary>
private string strRemotePass;
public string RemotePass
{
   set
   {
    strRemotePass = value;
   }
}

/// <summary>
/// 是否登录
/// </summary>
private Boolean bConnected;
public bool Connected
{
   get
   {
    return bConnected;
   }
}
#endregion

#region 链接
/// <summary>
/// 建立连接
/// </summary>
public void Connect()
{
   socketControl = new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
   IPEndPoint ep = new IPEndPoint(IPAddress.Parse(RemoteHost), strRemotePort);
   // 链接
   try
   {
    socketControl.Connect(ep);
   }
   catch(Exception)
   {
    throw new IOException("Couldn't connect to remote server");
   }

   // 获取应答码
   ReadReply();
   if(iReplyCode != 220)
   {
    DisConnect();
    throw new IOException(strReply.Substring(4));
   }

   // 登陆
   SendCommand("USER "+strRemoteUser);
   if( !(iReplyCode == 331 || iReplyCode == 230) )
   {
    CloseSocketConnect();//关闭连接
    throw new IOException(strReply.Substring(4));
   }
   if( iReplyCode != 230 )
   {
    SendCommand("PASS "+strRemotePass);
    if( !(iReplyCode == 230 || iReplyCode == 202) )
    {
     CloseSocketConnect();//关闭连接
     throw new IOException(strReply.Substring(4));
    }
   }
   bConnected = true;

   // 切换到目录
   ChDir(strRemotePath);
}

/// <summary>
/// 关闭连接
/// </summary>
public void DisConnect()
{
   if( socketControl != null )
   {
    SendCommand("QUIT");
   }
   CloseSocketConnect();
}

#endregion

#region 传输模式

/// <summary>
/// 传输模式:二进制类型、ASCII类型
/// </summary>
public enum TransferType {Binary,ASCII};

/// <summary>
/// 设置传输模式
/// </summary>
/// <param name="ttType">传输模式</param>
public void SetTransferType(TransferType ttType)
{
   if(ttType == TransferType.Binary)
   {
    SendCommand("TYPE I");//binary类型传输
   }
   else
   {
    SendCommand("TYPE A");//ASCII类型传输
   }
   if (iReplyCode != 200)
   {
    throw new IOException(strReply.Substring(4));
   }
   else
   {
    trType = ttType;
   }
}

/// <summary>
/// 获得传输模式
/// </summary>
/// <returns>传输模式</returns>
public TransferType GetTransferType()
{
return trType;
}

#endregion

#region 文件操作
/// <summary>
/// 获得文件列表
/// </summary>
/// <param name="strMask">文件名的匹配字符串</param>
/// <returns></returns>
public string[] Dir(string strMask)
{
   // 建立链接
   if(!bConnected)
   {
    Connect();
   }

   //建立进行数据连接的socket
   Socket socketData = CreateDataSocket();

   //传送命令
   SendCommand("NLST " + strMask);

   //分析应答代码
   if(!(iReplyCode == 150 || iReplyCode == 125 || iReplyCode == 226))
   {
    throw new IOException(strReply.Substring(4));
   }

   //获得结果
   strMsg = "";
   while(true)
   {
    int iBytes = socketData.Receive(buffer, buffer.Length, 0);
    strMsg += ASCII.GetString(buffer, 0, iBytes);
    if(iBytes < buffer.Length)
    {
     break;
    }
   }
   char[] seperator = {'\n'};
   string[] strsFileList = strMsg.Split(seperator);
   socketData.Close();//数据socket关闭时也会有返回码
   if(iReplyCode != 226)
   {
    ReadReply();
    if(iReplyCode != 226)
    {
     throw new IOException(strReply.Substring(4));
    }
   }
   return strsFileList;
}

/// <summary>
/// 获取文件大小
/// </summary>
/// <param name="strFileName">文件名</param>
/// <returns>文件大小</returns>
private long GetFileSize(string strFileName)
{
   if(!bConnected)
   {
    Connect();
   }
   SendCommand("SIZE " + Path.GetFileName(strFileName));
   long lSize=0;
   if(iReplyCode == 213)
   {
    lSize = Int64.Parse(strReply.Substring(4));
   }
   else
   {
    throw new IOException(strReply.Substring(4));
   }
   return lSize;
}

/// <summary>
/// 删除
/// </summary>
/// <param name="strFileName">待删除文件名</param>
public void Delete(string strFileName)
{
   if(!bConnected)
   {
    Connect();
   }
   SendCommand("DELE "+strFileName);
   if(iReplyCode != 250)
   {
    throw new IOException(strReply.Substring(4));
   }
}

/// <summary>
/// 重命名(如果新文件名与已有文件重名,将覆盖已有文件)
/// </summary>
/// <param name="strOldFileName">旧文件名</param>
/// <param name="strNewFileName">新文件名</param>
public void Rename(string strOldFileName,string strNewFileName)
{
   if(!bConnected)
   {
    Connect();
   }
   SendCommand("RNFR "+strOldFileName);
   if(iReplyCode != 350)
   {
    throw new IOException(strReply.Substring(4));
   }
   // 如果新文件名与原有文件重名,将覆盖原有文件
   SendCommand("RNTO "+strNewFileName);
   if(iReplyCode != 250)
   {
    throw new IOException(strReply.Substring(4));
   }
}
#endregion

#region 上传和下载
/// <summary>
/// 下载一批文件
/// </summary>
/// <param name="strFileNameMask">文件名的匹配字符串</param>
/// <param name="strFolder">本地目录(不得以\结束)</param>
public void Get(string strFileNameMask,string strFolder)
{
   if(!bConnected)
   {
    Connect();
   }
   string[] strFiles = Dir(strFileNameMask);
   foreach(string strFile in strFiles)
   {
    if(!strFile.Equals(""))//一般来说strFiles的最后一个元素可能是空字符串
    {
     Get(strFile,strFolder,strFile);
    }
   }
}

/// <summary>
/// 下载一个文件
/// </summary>
/// <param name="strRemoteFileName">要下载的文件名</param>
/// <param name="strFolder">本地目录(不得以\结束)</param>
/// <param name="strLocalFileName">保存在本地时的文件名</param>
public void Get(string strRemoteFileName,string strFolder,string strLocalFileName)
{
   if(!bConnected)
   {
    Connect();
   }
   SetTransferType(TransferType.Binary);
   if (strLocalFileName.Equals(""))
   {
    strLocalFileName = strRemoteFileName;
   }
   if(!File.Exists(strLocalFileName))
   {
    Stream st = File.Create(strLocalFileName);
    st.Close();
   }
   FileStream output = new
   FileStream(strFolder + "\\" + strLocalFileName,FileMode.Create);
   Socket socketData = CreateDataSocket();
   SendCommand("RETR " + strRemoteFileName);
   if(!(iReplyCode == 150 || iReplyCode == 125
   || iReplyCode == 226 || iReplyCode == 250))
   {
    throw new IOException(strReply.Substring(4));
   }
   while(true)
   {
    int iBytes = socketData.Receive(buffer, buffer.Length, 0);
    output.Write(buffer,0,iBytes);
    if(iBytes <= 0)
    {
     break;
    }
   }
   output.Close();
   if (socketData.Connected)
   {
    socketData.Close();
   }
   if(!(iReplyCode == 226 || iReplyCode == 250))
   {
    ReadReply();
    if(!(iReplyCode == 226 || iReplyCode == 250))
    {
     throw new IOException(strReply.Substring(4));
    }
   }
}

/// <summary>
/// 上传一批文件
/// </summary>
/// <param name="strFolder">本地目录(不得以\结束)</param>
/// <param name="strFileNameMask">文件名匹配字符(可以包含*和?)</param>
public void Put(string strFolder,string strFileNameMask)
{
   string[] strFiles = Directory.GetFiles(strFolder,strFileNameMask);
   foreach(string strFile in strFiles)
   {
    //strFile是完整的文件名(包含路径)
    Put(strFile);
   }
}

/// <summary>
/// 上传一个文件
/// </summary>
/// <param name="strFileName">本地文件名</param>
public void Put(string strFileName)
{
   if(!bConnected)
   {
    Connect();
   }
   Socket socketData = CreateDataSocket();
   SendCommand("STOR "+Path.GetFileName(strFileName));
   if( !(iReplyCode == 125 || iReplyCode == 150) )
   {
    throw new IOException(strReply.Substring(4));
   }
   FileStream input = new
   FileStream(strFileName,FileMode.Open);
   int iBytes = 0;
   while ((iBytes = input.Read(buffer,0,buffer.Length)) > 0)
   {
    socketData.Send(buffer, iBytes, 0);
   }
   input.Close();
   if (socketData.Connected)
   {
    socketData.Close();
   }
   if(!(iReplyCode == 226 || iReplyCode == 250))
   {
    ReadReply();
    if(!(iReplyCode == 226 || iReplyCode == 250))
    {
     throw new IOException(strReply.Substring(4));
    }
   }
}

#endregion

#region 目录操作
/// <summary>
/// 创建目录
/// </summary>
/// <param name="strDirName">目录名</param>
public void MkDir(string strDirName)
{
   if(!bConnected)
   {
    Connect();
   }
   SendCommand("MKD "+strDirName);
   if(iReplyCode != 257)
   {
    throw new IOException(strReply.Substring(4));
   }
}


/// <summary>
/// 删除目录
/// </summary>
/// <param name="strDirName">目录名</param>
public void RmDir(string strDirName)
{
   if(!bConnected)
   {
    Connect();
   }
   SendCommand("RMD "+strDirName);
   if(iReplyCode != 250)
   {
    throw new IOException(strReply.Substring(4));
   }
}


/// <summary>
/// 改变目录
/// </summary>
/// <param name="strDirName">新的工作目录名</param>
public void ChDir(string strDirName)
{
   if(strDirName.Equals(".") || strDirName.Equals(""))
   {
    return;
   }
   if(!bConnected)
   {
    Connect();
   }
   SendCommand("CWD "+strDirName);
   if(iReplyCode != 250)
   {
    throw new IOException(strReply.Substring(4));
   }
   this.strRemotePath = strDirName;
}

#endregion

#region 内部变量
/// <summary>
/// 服务器返回的应答信息(包含应答码)
/// </summary>
private string strMsg;
/// <summary>
/// 服务器返回的应答信息(包含应答码)
/// </summary>
private string strReply;
/// <summary>
/// 服务器返回的应答码
/// </summary>
private int iReplyCode;
/// <summary>
/// 进行控制连接的socket
/// </summary>
private Socket socketControl;
/// <summary>
/// 传输模式
/// </summary>
private TransferType trType;
/// <summary>
/// 接收和发送数据的缓冲区
/// </summary>
private static int BLOCK_SIZE = 512;
Byte[] buffer = new Byte[BLOCK_SIZE];
/// <summary>
/// 编码方式
/// </summary>
Encoding ASCII = Encoding.ASCII;
#endregion

#region 内部函数
/// <summary>
/// 将一行应答字符串记录在strReply和strMsg
/// 应答码记录在iReplyCode
/// </summary>
private void ReadReply()
{
   strMsg = "";
   strReply = ReadLine();
   iReplyCode = Int32.Parse(strReply.Substring(0,3));
}

/// <summary>
/// 建立进行数据连接的socket
/// </summary>
/// <returns>数据连接socket</returns>
private Socket CreateDataSocket()
{
   SendCommand("PASV");
   if(iReplyCode != 227)
   {
    throw new IOException(strReply.Substring(4));
   }
   int index1 = strReply.IndexOf('(');
   int index2 = strReply.IndexOf(')');
   string ipData =
    strReply.Substring(index1+1,index2-index1-1);
   int[] parts = new int[6];
   int len = ipData.Length;
   int partCount = 0;
   string buf="";
   for (int i = 0; i < len && partCount <= 6; i++)
   {
    char ch = Char.Parse(ipData.Substring(i,1));
    if (Char.IsDigit(ch))
     buf+=ch;
    else if (ch != ',')
    {
     throw new IOException("Malformed PASV strReply: " +
      strReply);
    }
    if (ch == ',' || i+1 == len)
    {
     try
     {
      parts[partCount++] = Int32.Parse(buf);
      buf="";
     }
     catch (Exception)
     {
      throw new IOException("Malformed PASV strReply: " +
       strReply);
     }
    }
   }
   string ipAddress = parts[0] + "."+ parts[1]+ "." +
    parts[2] + "." + parts[3];
   int port = (parts[4] << 8) + parts[5];
   Socket s = new
    Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
   IPEndPoint ep = new
    IPEndPoint(IPAddress.Parse(ipAddress), port);
   try
   {
    s.Connect(ep);
   }
   catch(Exception)
   {
    throw new IOException("Can't connect to remote server");
   }
   return s;
}

/// <summary>
/// 关闭socket连接(用于登录以前)
/// </summary>
private void CloseSocketConnect()
{
   if(socketControl!=null)
   {
    socketControl.Close();
    socketControl = null;
   }
   bConnected = false;
}

/// <summary>
/// 读取Socket返回的所有字符串
/// </summary>
/// <returns>包含应答码的字符串行</returns>
private string ReadLine()
{
   while(true)
   {
    int iBytes = socketControl.Receive(buffer, buffer.Length, 0);
    strMsg += ASCII.GetString(buffer, 0, iBytes);
    if(iBytes < buffer.Length)
    {
     break;
    }
   }
   char[] seperator = {'\n'};
   string[] mess = strMsg.Split(seperator);
   if(strMsg.Length > 2)
   {
    strMsg = mess[mess.Length-2];
    //seperator[0]是10,换行符是由13和0组成的,分隔后10后面虽没有字符串,
    //但也会分配为空字符串给后面(也是最后一个)字符串数组,
    //所以最后一个mess是没用的空字符串
    //但为什么不直接取mess[0],因为只有最后一行字符串应答码与信息之间有空格
   }
   else
   {
    strMsg = mess[0];
   }
   if(!strMsg.Substring(3,1).Equals(" "))//返回字符串正确的是以应答码(如220开头,后面接一空格,再接问候字符串)
   {
    return ReadLine();
   }
   return strMsg;
}

/// <summary>
/// 发送命令并获取应答码和最后一行应答字符串
/// </summary>
/// <param name="strCommand">命令</param>
private void SendCommand(String strCommand)
{
   Byte[] cmdBytes =
   Encoding.ASCII.GetBytes((strCommand+"\r\n").ToCharArray());
   socketControl.Send(cmdBytes, cmdBytes.Length, 0);
   ReadReply();
}

#endregion
}
}