关于做ftp控件的问题

Question

using System;
using System.Net;
using System.IO;
using System.Text;
using System.Net.Sockets;
//--------------------------------------------------------------------------------namespace FtpClass
{
/// <summary>
/// Ftp 的摘要说明。
/// </summary>
//--------------------------------------------------------------------------------
public class Ftp
{
private string 
remoteHost,remotePath,remoteUser,remotePass,mes;
private int remotePort,bytes;
private Socket clientSocket; private int retValue;
private Boolean debug;
private Boolean logined;
private string reply; private static int BLOCK_SIZE = 512; Byte[] buffer = new Byte[BLOCK_SIZE];
Encoding ASCII = Encoding.ASCII;
//--------------------------------------------------------------------------------
public Ftp()
{
//
// TODO: 在此处添加构造函数逻辑
//
remoteHost  = "localhost";
remotePath  = ".";
remoteUser  = "anonymous";
remotePass  = "[email protected]";
remotePort  = 21;
debug     = false;
logined    = false;
}
//--------------------------------------------------------------------------------
///
/// Set the name of the FTP server to connect to.
///
/// Server name
//--------------------------------------------------------------------------------
public void setRemoteHost(string remoteHost)
{
this.remoteHost = remoteHost;
}
//--------------------------------------------------------------------------------
///
/// Return the name of the current FTP server.
///
/// Server name
//--------------------------------------------------------------------------------
public string getRemoteHost()
{
return remoteHost;
}
//--------------------------------------------------------------------------------
///
/// Set the port number to use for FTP.
///
/// Port number
//--------------------------------------------------------------------------------
public void setRemotePort(int remotePort)
{
this.remotePort = remotePort;
}
//--------------------------------------------------------------------------------
///
/// Return the current port number.
///
/// Current port number
//--------------------------------------------------------------------------------
public int getRemotePort()
{
return remotePort;
}
//--------------------------------------------------------------------------------
///
/// Set the remote directory path.
///
/// The remote directory path
//--------------------------------------------------------------------------------
public void setRemotePath(string remotePath)
{
this.remotePath = remotePath;
}
//--------------------------------------------------------------------------------
///
/// Return the current remote directory path.
///
/// The current remote directory path.
//--------------------------------------------------------------------------------
public string getRemotePath()
{
return remotePath;
}
//--------------------------------------------------------------------------------
///
/// Set the user name to use for logging into the remote server.
///
/// Username
//--------------------------------------------------------------------------------
public void setRemoteUser(string remoteUser)
{
this.remoteUser = remoteUser;
}
//--------------------------------------------------------------------------------
///
/// Set the password to user for logging into the remote server.
///
/// Password
//--------------------------------------------------------------------------------
public void setRemotePass(string remotePass)
{
this.remotePass = remotePass;
}
//--------------------------------------------------------------------------------
///
/// Return a string array containing the remote directory's file list.
///
//--------------------------------------------------------------------------------
public void Error_getFileList()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public void Begin_getFileList(string mask)
{
}
//--------------------------------------------------------------------------------
public void After_getFileList(string[] FileList)
{
}
//--------------------------------------------------------------------------------
public string[] getFileList(string mask)
{
Begin_getFileList(mask);
if(!logined)
{
login();
}
Socket cSocket = createDataSocket();
sendCommand("NLST " + mask);
if(!(retValue == 150 || retValue == 125))
{
Error_getFileList();
return null;
}
mes = "";
while(true)
{
int bytes = cSocket.Receive(buffer, buffer.Length, 0);
mes += ASCII.GetString(buffer, 0, bytes);
if(bytes < buffer.Length)
{
break;
}
}
char[] seperator = {'\n'};
string[] mess = mes.Split(seperator);
cSocket.Close();
readReply();
if(retValue != 226)
{
Error_getFileList();
return null;
}
After_getFileList(mess);
return mess;
}

Answer 1

//--------------------------------------------------------------------------------
///
/// Return the size of a file.
///
//--------------------------------------------------------------------------------
public void Error_getFileSize()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public long getFileSize(string fileName)
{ if(!logined)
{
login();
}
sendCommand("SIZE " + fileName);
long size=0; if(retValue == 213)
{
size = Int64.Parse(reply.Substring(4));
}
else
{
Error_getFileSize();
return -1;
}
return size;
}
//--------------------------------------------------------------------------------
///
/// Login to the remote server.
///
//--------------------------------------------------------------------------------
public void Error_login()
{
throw new IOException("Couldn't connect to remote server");
}
//--------------------------------------------------------------------------------
public void Begin_login()
{
}
//--------------------------------------------------------------------------------
public void After_login(bool Success)
{
}
//--------------------------------------------------------------------------------
public void login()
{
Begin_login();
clientSocket = new Socket(AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
IPEndPoint ep = new IPEndPoint(Dns.Resolve(remoteHost).AddressList[0], remotePort);
try
{
clientSocket.Connect(ep);
}
catch(Exception)
{
Error_login();
After_login(false);
return;
}
readReply();
if(retValue != 220)
{
close();
Error_login();
After_login(false);
return;
}
if(debug)
Console.WriteLine("USER "+remoteUser);
sendCommand("USER "+remoteUser);
if( !(retValue == 331 || retValue == 230) )
{
cleanup();
Error_login();
After_login(false);
return;
}
if( retValue != 230 )
{
if(debug)
Console.WriteLine("PASS xxx");
sendCommand("PASS "+remotePass);
if( !(retValue == 230 || retValue == 202) )
{
cleanup();
Error_login();
After_login(false);
return;
}
}
logined = true;
Console.WriteLine("Connected to "+remoteHost);
After_login(true);
chdir(remotePath);
}
//--------------------------------------------------------------------------------
///
/// If the value of mode is true, set binary mode for downloads.
/// Else, set Ascii mode.
///
//--------------------------------------------------------------------------------
public void Error_setBinaryMode()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public void setBinaryMode(Boolean mode)
{ if(mode)
{
sendCommand("TYPE I");
}
else
{
sendCommand("TYPE A");
}
if (retValue != 200)
{
//throw new IOException(reply.Substring(4));
Error_setBinaryMode();
return;
}
}
//--------------------------------------------------------------------------------
public void Error_download()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public void Begin_download(string remFileName,string locFileName,bool resume)
{
}
//--------------------------------------------------------------------------------
public void After_download(bool Success)
{
}
//--------------------------------------------------------------------------------
///
/// Download a file to the Assembly's local directory,
/// keeping the same file name.
///
//--------------------------------------------------------------------------------
public void download(string remFileName)
{
download(remFileName,"",false);
}
//--------------------------------------------------------------------------------
///
/// Download a remote file to the Assembly's local directory,
/// keeping the same file name, and set the resume flag.
///
//--------------------------------------------------------------------------------
public void download(string remFileName,Boolean resume)
{
download(remFileName,"",resume);
}
//--------------------------------------------------------------------------------
///
/// Download a remote file to a local file name which can include
/// a path. The local file name will be created or overwritten,
/// but the path must exist.
///
//--------------------------------------------------------------------------------
public void download(string remFileName,string locFileName)
{
download(remFileName,locFileName,false);
}
//--------------------------------------------------------------------------------
///
/// Download a remote file to a local file name which can include
/// a path, and set the resume flag. The local file name will be
/// created or overwritten, but the path must exist.
///
//--------------------------------------------------------------------------------
public void download(string remFileName,string locFileName,Boolean resume)
{
Begin_download(remFileName,locFileName,resume);
if(!logined)
{
login();
}
setBinaryMode(true);
Console.WriteLine("Downloading file "+remFileName+" from "+remoteHost + "/"+remotePath);
if (locFileName.Equals(""))
{
locFileName = remFileName;
}
if(!File.Exists(locFileName))
{
Stream st = File.Create(locFileName);
st.Close();
}
FileStream output = new FileStream(locFileName,FileMode.Open);
Socket cSocket = createDataSocket();
long offset = 0;
if(resume)
{
offset = output.Length;
if(offset > 0 )
{
sendCommand("REST "+offset);
if(retValue != 350)
{
//Some servers may not support resuming.
offset = 0;
}
}
if(offset > 0)
{
if(debug)
{
Console.WriteLine("seeking to " + offset);
}
long npos = output.Seek(offset,SeekOrigin.Begin);
Console.WriteLine("new pos="+npos);
}
}
sendCommand("RETR " + remFileName);
if(!(retValue == 150 || retValue == 125))
{
Error_download();
After_download(false);
return;
}
while(true)
{ bytes = cSocket.Receive(buffer, buffer.Length, 0);
output.Write(buffer,0,bytes); if(bytes <= 0)
{
break;
}
}
output.Close();
if (cSocket.Connected)
{
cSocket.Close();
}
Console.WriteLine("");
readReply();
if( !(retValue == 226 || retValue == 250) )
{
Error_download();
After_download(false); 
return;
}
After_download(true);
}

Answer 2

//--------------------------------------------------------------------------------
public void Error_upload()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public void Begin_upload(string fileName,Boolean resume)
{
}
//--------------------------------------------------------------------------------
public void After_upload(bool Success)
{
}
//--------------------------------------------------------------------------------
///
/// Upload a file.
///
//--------------------------------------------------------------------------------
public void upload(string fileName)
{
upload(fileName,false);
}
//--------------------------------------------------------------------------------
///
/// Upload a file and set the resume flag.
///
//--------------------------------------------------------------------------------
public void upload(string fileName,Boolean resume)
{
Begin_upload(fileName,resume);
if(!logined)
{
login();
}
Socket cSocket = createDataSocket();
long offset=0;
if(resume)
{
try
{
setBinaryMode(true);
offset = getFileSize(fileName);
}
catch(Exception)
{
offset = 0;
}
}
if(offset > 0 )
{
sendCommand("REST " + offset);
if(retValue != 350)
{
//Remote server may not support resuming.
offset = 0;
}
}
sendCommand("STOR "+Path.GetFileName(fileName));
if( !(retValue == 125 || retValue == 150) )
{
Error_upload();
After_upload(false);
return;
}
// open input stream to read source file
FileStream input = new FileStream(fileName,FileMode.Open);
if(offset != 0)
{
if(debug)
{
Console.WriteLine("seeking to " + offset);
}
input.Seek(offset,SeekOrigin.Begin);
}
Console.WriteLine("Uploading file "+fileName+" to "+remotePath);
while ((bytes = input.Read(buffer,0,buffer.Length)) > 0)
{
cSocket.Send(buffer, bytes, 0);
}
input.Close(); Console.WriteLine(""); if (cSocket.Connected)
{
cSocket.Close();
}
readReply();
if( !(retValue == 226 || retValue == 250) )
{
Error_upload();
After_upload(false);
return;
}
After_upload(true);
}
//--------------------------------------------------------------------------------
public void Error_deleteRemoteFile()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public void Begin_deleteRemoteFile(string fileName)
{
}
//--------------------------------------------------------------------------------
public void After_deleteRemoteFile(bool Success)
{
}
//--------------------------------------------------------------------------------
/// 
/// Delete a file from the remote FTP server.
///
//--------------------------------------------------------------------------------
public void deleteRemoteFile(string fileName)
{
Begin_deleteRemoteFile(fileName);
if(!logined)
{
login();
}
sendCommand("DELE "+fileName);
if(retValue != 250)
{
Error_deleteRemoteFile();
After_deleteRemoteFile(false);
return;
}
After_deleteRemoteFile(true);
}
//--------------------------------------------------------------------------------
public void Error_renameRemoteFile()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public void Begin_renameRemoteFile(string oldFileName,string newFileName) 
{
}
//--------------------------------------------------------------------------------
public void After_renameRemoteFile(bool Success)
{
}
//--------------------------------------------------------------------------------
///
/// Rename a file on the remote FTP server.
///
//--------------------------------------------------------------------------------
public void renameRemoteFile(string oldFileName,string newFileName)
{
Begin_renameRemoteFile(oldFileName,newFileName);
if(!logined)
{
login();
}
sendCommand("RNFR "+oldFileName);
if(retValue != 350)
{
Error_renameRemoteFile();
After_renameRemoteFile(false);
return;
}
//  known problem
//  rnto will not take care of existing file.
//  i.e. It will overwrite if newFileName exist
sendCommand("RNTO "+newFileName);
if(retValue != 250)
{
Error_renameRemoteFile();
After_renameRemoteFile(false);
return;
}
After_renameRemoteFile(true);
}

Answer 3

//--------------------------------------------------------------------------------
public void Error_mkdir()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public void Begin_mkdir(string dirName)
{
}
//--------------------------------------------------------------------------------
public void After_mkdir(bool Success)
{
}
//--------------------------------------------------------------------------------
///
/// Create a directory on the remote FTP server.
///
//--------------------------------------------------------------------------------
public void mkdir(string dirName)
{
Begin_mkdir(dirName); 
if(!logined)
{
login();
}
sendCommand("MKD "+dirName);
if(retValue != 250)
{
//throw new IOException(reply.Substring(4));
Error_mkdir();
After_mkdir(false);
return;
}
After_mkdir(true);
}
//--------------------------------------------------------------------------------
public void Error_rmdir()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public void Begin_rmdir(string dirName)
{
}
//--------------------------------------------------------------------------------
public void After_rmdir(bool Success)
{
}
//--------------------------------------------------------------------------------
///
/// Delete a directory on the remote FTP server.
///
//--------------------------------------------------------------------------------
public void rmdir(string dirName)
{
Begin_rmdir(dirName);
if(!logined)
{
login();
}
sendCommand("RMD "+dirName);
if(retValue != 250)
{
Error_rmdir();
After_rmdir(false);
return;
}
After_rmdir(true);
}
//--------------------------------------------------------------------------------
public void Error_chdir()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public void Begin_chdir(string dirName)
{
}
//--------------------------------------------------------------------------------
public void After_chdir(bool Success)
{
}
//--------------------------------------------------------------------------------
///
/// Change the current working directory on the remote FTP server.
///
//--------------------------------------------------------------------------------
public void chdir(string dirName)
{
Begin_chdir(dirName);
if(dirName.Equals("."))
{
return;
} if(!logined)
{
login();
}
sendCommand("CWD "+dirName);
if(retValue != 250)
{
Error_chdir();
After_chdir(false);
return;
}
this.remotePath = dirName;
Console.WriteLine("Current directory is "+remotePath);
After_chdir(true);
}
//--------------------------------------------------------------------------------
///
/// Close the FTP connection.
///
//--------------------------------------------------------------------------------
public void close()
{ if( clientSocket != null )
{
sendCommand("QUIT");
} cleanup();
Console.WriteLine("Closing...");
}

Answer 4

//--------------------------------------------------------------------------------
///
/// Set debug mode.
///
//--------------------------------------------------------------------------------
public void setDebug(Boolean debug)
{
this.debug = debug;
}
//--------------------------------------------------------------------------------
private void readReply()
{
mes = "";
reply = readLine();
retValue = Int32.Parse(reply.Substring(0,3));
}
//--------------------------------------------------------------------------------
private void cleanup()
{
if(clientSocket!=null)
{
clientSocket.Close();
clientSocket = null;
}
logined = false;
}
//--------------------------------------------------------------------------------
private string readLine()
{ while(true)
{
bytes = clientSocket.Receive(buffer, buffer.Length, 0);
mes += ASCII.GetString(buffer, 0, bytes);
if(bytes < buffer.Length)
{
break;
}
}
char[] seperator = {'\n'};
string[] mess = mes.Split(seperator);
if(mes.Length > 2)
{
mes = mess[mess.Length-2];
}
else
{
mes = mess[0];
}
if(!mes.Substring(3,1).Equals(" "))
{
return readLine();
}
if(debug)
{
for(int k=0;k < mess.Length-1;k++)
{
Console.WriteLine(mess[k]);
}
}
return mes;
}
//--------------------------------------------------------------------------------
private void sendCommand(String command)
{ Byte[] cmdBytes = 
Encoding.ASCII.GetBytes((command+"\r\n").ToCharArray());
clientSocket.Send(cmdBytes, cmdBytes.Length, 0);
readReply();
}
//--------------------------------------------------------------------------------
public void Error_createDataSocket()
{
throw new IOException(reply.Substring(4));
}
//--------------------------------------------------------------------------------
public void Begin_createDataSocket()
{
}
//--------------------------------------------------------------------------------
public void After_createDataSocket(bool Success)
{
}
//--------------------------------------------------------------------------------
private Socket createDataSocket()
{
Begin_createDataSocket(); 
sendCommand("PASV");
if(retValue != 227)
{
Error_createDataSocket();
After_createDataSocket(false);
return null;
}
int index1 = reply.IndexOf('(');
int index2 = reply.IndexOf(')');
string ipData = reply.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 != ',')
{
Error_createDataSocket();
After_createDataSocket(false);
return null;
}
if (ch == ',' || i+1 == len)
{
try
{
parts[partCount++] = Int32.Parse(buf);
buf="";
}
catch (Exception)
{
Error_createDataSocket();
After_createDataSocket(false);
return null;
}
}
}
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(Dns.Resolve(ipAddress).AddressList[0], port);
try
{
s.Connect(ep);
}
catch(Exception)
{
Error_createDataSocket();
return null;
After_createDataSocket(false);
}
After_createDataSocket(true);
return s;
}
}
}    

Answer 5

最后的
Error_createDataSocket();
return null;
After_createDataSocket(false);
应该是
Error_createDataSocket();
After_createDataSocket(false);
return null;