掌握socket基于事件机制的网络程序设计，掌握多线程技术的FTP Server端设计方法，掌握FTP标准基本协议及其程序的实现，掌握文件内容的网络传输设计方法。
利用CFtpServer类接收和解析客户端命令，编写FTP客户端程序，服务器端使用多线程，实现多用户同时登录管理；
利用CFtpConnection和CInternetSession类，编写FTP客户端，实现简单文件操作功能。
- FTP服务器实现
1.服务器窗口界面设计
服务器主界面
2.功能实现：
（1）初始化FTP并启动监听
BOOL CFTPServer::Start()
{
if (m_bRunning)
return FALSE;
// create dummy window for message routing
if (!CWnd::CreateEx(0, AfxRegisterWndClass(0), "FTP Server Notification Sink", WS_POPUP, 0,0,0,0, NULL, 0))
{
AddTraceLine(0, "Failed to create notification window.");
return FALSE;
}
// created the listen socket
if (m_ListenSocket.Create(m_nPort))
{
// start listening
if (m_ListenSocket.Listen())
{
m_ListenSocket.m_pWndServer = this;
m_bRunning = TRUE;
SetTimer(1, m_nStatisticsInterval, NULL);
AddTraceLine(0, "FTP Server started on port %d.", m_nPort);
return TRUE;
}
}
AddTraceLine(0, "FTP Server failed to listen on port %d.", m_nPort);
// destroy notification window
if (IsWindow(m_hWnd))
DestroyWindow();
m_hWnd = NULL;
return FALSE;
}
（2）停止FTP
通知各线程停止监听，关闭进程，释放连接，实现代码如下
void CFTPServer::Stop()
{
if (!m_bRunning)
return;
// stop statistics timer
KillTimer(1);
m_bRunning = FALSE;
m_ListenSocket.Close();
CConnectThread* pThread = NULL;
// close all running threads
do
{
m_CriticalSection.Lock();
POSITION pos = m_ThreadList.GetHeadPosition();
if (pos != NULL)
{
pThread = (CConnectThread *)m_ThreadList.GetAt(pos);
m_CriticalSection.Unlock();
// save thread members
int nThreadID = pThread->m_nThreadID;
HANDLE hThread = pThread->m_hThread;
AddTraceLine(0, "[%u] Shutting down thread...", nThreadID);
// tell thread to stop
pThread->SetThreadPriority(THREAD_PRIORITY_HIGHEST);
pThread->PostThreadMessage(WM_QUIT,0,0);
// wait for thread to end, while keeping the messages pumping (max 5 seconds)
if (WaitWithMessageLoop(hThread, 5000) == FALSE)
{
// thread doesn't want to stopped
AddTraceLine(0, "[%u] Problem while killing thread.", nThreadID);
// don't try again, so remove
m_CriticalSection.Lock();
POSITION rmPos = m_ThreadList.Find(pThread);
if (rmPos != NULL)
m_ThreadList.RemoveAt(rmPos);
m_CriticalSection.Unlock();
}
else
{
AddTraceLine(0, "[%u] Thread successfully stopped.", nThreadID);
}
}
else
{
m_CriticalSection.Unlock();
pThread = NULL;
}
}
while (pThread != NULL);
AddTraceLine(0, "FTP Server stopped.");
if (IsWindow(m_hWnd))
DestroyWindow();
m_hWnd = NULL;
}
（3）账号操作
用户账号操作包括：添加，编辑、删除和保存，具体实现代码如下：
//添加账号
void CUserAccountPage::OnAddUser()
{
CAddUserDlg dlg;
if (dlg.DoModal() == IDOK)
{
for (int i=0; i<m_UsersList.GetItemCount(); i++)
{
CString strName;
strName = m_UsersList.GetItemText(i, 0);
if (strName.CompareNoCase(dlg.m_strName) == 0)
{
AfxMessageBox("Sorry, this user already exists!");
return;
}
}
CUser user;
user.m_strName = dlg.m_strName;
user.m_strPassword = "";
int nItem = m_UsersList.InsertItem(0, user.m_strName, 0);
if (nItem <= m_nPreviousIndex)
m_nPreviousIndex++;
// add home directory item
user.m_bAllowCreateDirectory = FALSE;
user.m_bAllowDelete = FALSE;
user.m_bAllowDownload = TRUE;
user.m_bAllowRename = FALSE;
user.m_bAllowUpload = FALSE;
user.m_strHomeDirectory = "";
int index = m_UserArray.Add(user);
m_UsersList.SetItemData(nItem, index);
m_UsersList.SetItemState(nItem, LVIS_SELECTED | LVIS_FOCUSED , LVIS_SELECTED | LVIS_FOCUSED);
OnSelchangeUserlist();
// update user manager
theServer.m_UserManager.UpdateUserList(m_UserArray);
SetModified();
// launch directory browser
PostMessage(WM_COMMAND, IDC_BROWSE);
}
}
//更改用户名
void CUserAccountPage::OnEditUser()
{
// get selected user
int nSelIndex = m_UsersList.GetNextItem(-1, LVNI_ALL | LVNI_SELECTED);
if(nSelIndex == -1)
return;
int nUserIndex = m_UsersList.GetItemData(nSelIndex);
CAddUserDlg dlg;
dlg.m_strTitle = "修改";
dlg.m_strName = m_UserArray[nUserIndex].m_strName;
if (dlg.DoModal() == IDOK)
{
// check if user already exists
for (int i=0; i<m_UsersList.GetItemCount(); i++)
{
if (i != nSelIndex)
{
CString strName;
strName = m_UsersList.GetItemText(i, 0);
if (strName.CompareNoCase(dlg.m_strName) == 0)
{
AfxMessageBox("Sorry, this user already exists!");
return;
}
}
}
m_UserArray[nUserIndex].m_strName = dlg.m_strName;
m_UsersList.DeleteItem(nSelIndex);
nSelIndex = m_UsersList.InsertItem(0, dlg.m_strName, 0);
m_UsersList.SetItemData(nSelIndex, nUserIndex);
m_UsersList.SetItemState(nSelIndex, LVIS_SELECTED | LVIS_FOCUSED , LVIS_SELECTED | LVIS_FOCUSED);
m_nPreviousIndex = nSelIndex;
OnSelchangeUserlist();
// update user manager
theServer.m_UserManager.UpdateUserList(m_UserArray);
SetModified(FALSE);
}
}
//更改用户目录
void CUserAccountPage::OnBrowse()
{
CString strDir = BrowseForFolder(m_hWnd, "Select a home directory:", BIF_RETURNONLYFSDIRS);
if (!strDir.IsEmpty())
{
m_strHomeDirectory = strDir;
UpdateData(FALSE);
}
}
//删除账号
void CUserAccountPage::OnDelUser()
{
int nSelIndex = m_UsersList.GetNextItem(-1, LVNI_ALL | LVNI_SELECTED);
if(nSelIndex == -1)
return;
CString strText;
strText.Format("Are you sure you want to delete '%s'?", m_UsersList.GetItemText(nSelIndex, 0));
if (MessageBox(strText, "FTP Server", MB_YESNO | MB_ICONQUESTION) != IDYES)
{
return;
}
int nUserIndex = m_UsersList.GetItemData(nSelIndex);
// remove user from array
m_UserArray.RemoveAt(nUserIndex);
m_nPreviousIndex = -1;
// update item data values
m_UsersList.SetRedraw(FALSE);
m_UsersList.DeleteAllItems();
// update user list
for (int i=0; i < m_UserArray.GetSize(); i++)
{
int nIndex = m_UsersList.InsertItem(0, m_UserArray[i].m_strName, 0);
m_UsersList.SetItemData(nIndex, i);
}
m_UsersList.SetRedraw(TRUE);
// update user manager
theServer.m_UserManager.UpdateUserList(m_UserArray);
SetModified(FALSE);
m_UsersList.SetItemState(nSelIndex-1, LVIS_SELECTED | LVIS_FOCUSED , LVIS_SELECTED | LVIS_FOCUSED);
OnSelchangeUserlist();
}
//保存当前修改
BOOL CUserAccountPage::UpdateAccount(int nSelIndex)
{
if (nSelIndex == -1)
{
// get selected user
nSelIndex = m_UsersList.GetNextItem(-1, LVNI_ALL | LVNI_SELECTED);
}
if (nSelIndex != -1)
{
UpdateData();
int nUserIndex = m_UsersList.GetItemData(nSelIndex);
m_UserArray[nUserIndex].m_strPassword = m_strPassword;
m_UserArray[nUserIndex].m_bAccountDisabled = m_bDisableAccount;
// check if it's a valid directory
if (GetFileAttributes(m_strHomeDirectory) == 0xFFFFFFFF)
{
MessageBox("Please enter a valid home directory", "FTP Server", MB_OK | MB_ICONEXCLAMATION);
GetDlgItem(IDC_HOME_DIRECTORY)->SetFocus();
m_UsersList.SetItemState(m_nPreviousIndex, LVIS_SELECTED | LVIS_FOCUSED , LVIS_SELECTED | LVIS_FOCUSED);
return FALSE;
}
m_UserArray[nUserIndex].m_strHomeDirectory = m_strHomeDirectory;
m_UserArray[nUserIndex].m_bAllowCreateDirectory = m_bAllowCreateDirectory;
m_UserArray[nUserIndex].m_bAllowDelete = m_bAllowDelete;
m_UserArray[nUserIndex].m_bAllowDownload = m_bAllowDownload;
m_UserArray[nUserIndex].m_bAllowRename = m_bAllowRename;
m_UserArray[nUserIndex].m_bAllowUpload = m_bAllowUpload;
// update user manager
theServer.m_UserManager.UpdateUserList(m_UserArray);
return TRUE;
}
return FALSE;
}
（4）查看在线用户及其使用的线程号
在线用户显示页面主要代码如下：
BOOL COnlineUsersPage::OnInitDialog()
{
CDialog::OnInitDialog();
m_OnlineUsers.InsertColumn(0, "ThreadID");
m_OnlineUsers.InsertColumn(1, "Username");
m_OnlineUsers.InsertColumn(2, "IP Adress");
m_OnlineUsers.InsertColumn(3, "Login Time");
DWORD dwStyle = m_OnlineUsers.GetExtendedStyle();
dwStyle |= LVS_EX_FULLROWSELECT;
m_OnlineUsers.SetExtendedStyle(dwStyle);
return TRUE;
}
void COnlineUsersPage::OnSize(UINT nType, int cx, int cy)
{
CDialog::OnSize(nType, cx, cy);
if (IsWindow(::GetDlgItem(m_hWnd, IDC_ONLINE_USERS)))
{
CRect rect;
GetClientRect(rect);
m_OnlineUsers.MoveWindow(rect);
m_OnlineUsers.SetColumnWidth(0, 0);
m_OnlineUsers.SetColumnWidth(1, rect.Width()/3-2);
m_OnlineUsers.SetColumnWidth(2, rect.Width()/3-2);
m_OnlineUsers.SetColumnWidth(3, rect.Width()/3-2);
}
}
void COnlineUsersPage::AddUser(DWORD nThreadID, LPCTSTR lpszName, LPCTSTR lpszAddress)
{
CString strThreadID;
strThreadID.Format("%d", nThreadID);
LVFINDINFO info;
info.flags = LVFI_PARTIAL|LVFI_STRING;
info.psz = (LPCTSTR)strThreadID;
int nIndex = m_OnlineUsers.FindItem(&info);
if (nIndex == -1)
{
nIndex = m_OnlineUsers.InsertItem(0, strThreadID);
}
m_OnlineUsers.SetItemText(nIndex, 1, lpszName);
m_OnlineUsers.SetItemText(nIndex, 2, lpszAddress);
m_OnlineUsers.SetItemText(nIndex, 3, CTime::GetCurrentTime().Format("%H:%M:%S"));
}
void COnlineUsersPage::RemoveUser(DWORD nThreadID)
{
LVFINDINFO info;
CString strThreadID;
strThreadID.Format("%d", nThreadID);
info.flags = LVFI_PARTIAL|LVFI_STRING;
info.psz = (LPCTSTR)strThreadID;
int nIndex = m_OnlineUsers.FindItem(&info);
if (nIndex != -1)
{
m_OnlineUsers.DeleteItem(nIndex);
}
}
void COnlineUsersPage::OnContextMenu(CWnd* pWnd, CPoint point)
{
// get selected user
int nIndex = m_OnlineUsers.GetNextItem(-1, LVNI_ALL | LVNI_SELECTED);
if(nIndex == -1)
return;
CMenu menu;
menu.LoadMenu(MAKEINTRESOURCE(IDR_ONLINE_MENU));
menu.GetSubMenu(0)->TrackPopupMenu(0, point.x, point.y, this, NULL);
}
void COnlineUsersPage::OnKickUser()
{
int nIndex = m_OnlineUsers.GetNextItem(-1, LVNI_ALL | LVNI_SELECTED);
while (nIndex != -1)
{
CString strThreadID = m_OnlineUsers.GetItemText(nIndex, 0);
PostThreadMessage(atoi(strThreadID), WM_QUIT, 0 ,0);
nIndex = m_OnlineUsers.GetNextItem(nIndex, LVNI_ALL | LVNI_SELECTED);
}
}
void COnlineUsersPage::OnCancel()
{
// CDialog::OnCancel();
}
void COnlineUsersPage::OnOK()
{
// CDialog::OnOK();
}
- FTP客户端实现
为检验FTP客户端的可用性和进一步掌握FTP标准基本协议及文件内容的网络传输设计方法，我实现了一个简单的FTP客户端程序。
1.客户端窗口界面设计
FTP客户端程序主界面
2.功能实现：
（1）服务器的连接与断开
void CFTPClientDlg::OnButtonConnect()
{
// TODO: Add your control notification handler code here
UpdateData(TRUE);
if(!m_ftpConnection){
if(m_str_address!=""){
m_ftpConnection=m_internetSession.GetFtpConnection(m_str_address,m_str_username,m_str_password);
if(m_ftpConnection){
m_ftpConnection->GetCurrentDirectory(m_str_server_dir);
UpdateData(FALSE);
LoadFileList();
m_btn_connect.SetWindowText("断开");
}
}
}
else{
m_ftpConnection->Close();
delete m_ftpConnection;
m_ftpConnection=NULL;
m_btn_connect.SetWindowText("连接");
m_str_server_dir="";
m_listbox_files.ResetContent();
UpdateData(FALSE);
}
}
（2）加载文件、目录信息
void CFTPClientDlg::LoadFileList()
{
m_listbox_files.ResetContent();
CFtpFileFind fileFind(m_ftpConnection);
CString fileName;
BOOL bMoreFiles=fileFind.FindFile();
while(bMoreFiles)
{
bMoreFiles=fileFind.FindNextFile();
fileName=fileFind.GetFileName();
if(fileFind.IsDirectory()){
fileName+=" <dir>";
}
m_listbox_files.AddString(fileName);
}
fileFind.Close();
}
（3）下载文件
void CFTPClientDlg::OnButtonDownload()
{
// TODO: Add your control notification handler code here
UpdateData(TRUE);
if(m_str_filename!=""){
if(m_str_filename.Right(5)=="<dir>"){
MessageBox("不能下载目录");
}
else{
CFileDialog saveDialog(FALSE,NULL,m_str_filename);
if(saveDialog.DoModal()==IDOK)
{
if(!m_ftpConnection->GetFile(m_str_filename,saveDialog.GetFileName()),FALSE)
MessageBox("文件下载失败！");
else
MessageBox("成功下载 "+m_str_filename);
}
}
}
}
五. 实验结果
服务器运行效果如下：
主界面，运行状态显示
账号列表，编辑用户信息
在线用户列表
客户端运行效果如下：
不足的是，本次设计的FTP客户端程序较简单，只是为了简单验证服务器的可用性，所以只实现了文件的下载功能，后期将会尝试加上文件上传、删除以及目录创建等功能。