www.pudn.com > downloadingNet.rar > inet.cpp

 
/* 
	Inet.cpp : implementation of the CInet class 
 
	Implements the internet communication class responsible for downloading files 
	from the web server.  It is basically a wrapper class for the WinInet calls. 
 
	Author: Steven E. Sipe 
*/ 
 
#include "stdafx.h" 
 
#include  
#include  
#include  
 
#include "inet.h" 
 
// Filenames to create if a link just uses a directory for a reference --  
// g_szDefPage is for HTML pages, g_szUnknown is for multimedia files (in which 
// case something fatal happened) 
//  
const char *g_szDefPage = "index.htm"; 
const char *g_szUnknown = "unknown.fil"; 
 
// 定义协议类型即HTTP类型 
static const char *szHttp = "http://"; 
 
// Request flags for session initialization: 
//	Use existing INET setup, don't redirect to other servers automatically, 
//	don't save pages in the browser's cache, always reload a page from the  
//	server (don't use the browser's cached copy) 
 
static DWORD dwHttpRequestFlags = 
	   INTERNET_FLAG_EXISTING_CONNECT| 
	   INTERNET_FLAG_NO_AUTO_REDIRECT| 
       INTERNET_FLAG_DONT_CACHE| 
       INTERNET_FLAG_RELOAD;  
 
// 能够处理的数据类型，下面的定义表示能够处理所有的类型 
static const TCHAR szHeaders[] =  
//		_T("Accept: */*\r\n"); 
		_T("Accept: */* \r"); 
 
// 构造函数 
CInet::CInet() 
{ 
	m_hSession = NULL; 
	m_nUniqueCount = 0; 
} 
 
// 析构函数 
CInet::~CInet() 
{ 
} 
 
// 初始化一个新的WinInet 会话 
CInet::RESULTS CInet::OpenSession(BOOL bUseProxy, CString& strProxyName) 
{ 
	CInet::RESULTS ret; 
 
	// 打开 
	m_hSession = ::InternetOpen("SiteSnagger", 
					bUseProxy?INTERNET_OPEN_TYPE_PROXY:INTERNET_OPEN_TYPE_PRECONFIG, 
					bUseProxy?(LPCTSTR)strProxyName:(LPCTSTR)NULL, 
					NULL,0); 
 
	// 是否成功 
	if(m_hSession != NULL) 
	{ 
		DWORD dwTimeout = 4000; 
		::InternetSetOption(m_hSession,INTERNET_OPTION_CONNECT_TIMEOUT, 
									&dwTimeout,sizeof(dwTimeout)); 
						 
		ret = SUCCESS; 
	} 
	else ret = BAD_URL; 
 
	return(ret); 
} 
 
// Close the WinInet session 
void CInet::CloseSession() 
{ 
	::InternetCloseHandle(m_hSession); 
} 
 
////////////////////// 
// Private operations 
////////////////////// 
 
// 从远程服务器获得指定的文件 
CInet::RESULTS CInet::DoGet(CString& strURL, BYTE **pbyBuffer, int& nLen,  
											BOOL bIsTextPage) 
{ 
	CInet::RESULTS nRetCode = UNKNOWN_ERROR; 
	CString strTempURL = strURL; 
	HINTERNET hConnect = NULL; 
	HINTERNET hURL = NULL; 
    
    try 
	{ 
		// 初始化返回的数据大笑 
		nLen = 0; 
		 
		// 确保文件路径正确 
		strTempURL.MakeLower(); 
		if(strTempURL.Find(szHttp) < 0) 
		{ 
			strTempURL = szHttp+strURL; 
			strURL = szHttp+strURL; 
		} 
		else strTempURL = strURL; 
 
		// 确保文件路径合法 
		CString strServer,strObject,strUser,strPassword; 
		INTERNET_PORT nPort; 
		DWORD dwServiceType; 
 
		// 文件路径修正 
		strTempURL.SpanExcluding("#"); 
		if(!AfxParseURLEx(strTempURL,dwServiceType,strServer,strObject,nPort, 
						strUser,strPassword,ICU_NO_ENCODE)) 
			return(CInet::BAD_URL); 
 
		// 建立服务器连接 
		hConnect = ::InternetConnect(m_hSession,strServer, 
                                          INTERNET_INVALID_PORT_NUMBER, 
                                          strUser, 
                                          strPassword, 
                                          INTERNET_SERVICE_HTTP, 
                                          0, 
                                          0) ; 
 
		// 打开HTTP会话 
		strObject = strObject.SpanExcluding("#"); 
		const char *szTempX[2] = {szHeaders,NULL}; 
		hURL = ::HttpOpenRequest(hConnect,"GET",strObject, 
									HTTP_VERSION,NULL, 
                                    szTempX,dwHttpRequestFlags,0) ; 
 
		// 发送请求 
 		::HttpSendRequest(hURL,NULL,0,0,0); 
 
		// 如果失败，则返回 
	    if(hURL == NULL)  
			return(CInet::BAD_URL); 
 
		// 检查返回码 
		DWORD dwRet, dwLen; 
		char szTemp[500]; 
		dwLen = sizeof(szTemp); 
		::HttpQueryInfo(hURL,HTTP_QUERY_STATUS_CODE,szTemp,&dwLen,NULL); 
		dwRet = (DWORD) atoi(szTemp); 
		dwLen = sizeof(szTemp); 
		 
		m_dwRet = dwRet; 
 
		// 需要重定向该页面 
		if(dwRet == HTTP_STATUS_MOVED || dwRet == HTTP_STATUS_REDIRECT || 
			       dwRet == HTTP_STATUS_REDIRECT_METHOD) 
		{                   
			// 获得新的地址 
			CString strNewLocation; 
			::HttpQueryInfo(hURL,HTTP_QUERY_LOCATION,NULL,&dwLen,0); 
			::HttpQueryInfo(hURL,HTTP_QUERY_LOCATION, 
						strNewLocation.GetBufferSetLength(dwLen),  
						&dwLen,0); 
			strNewLocation.ReleaseBuffer(dwLen); 
 
			// 确信新地址包含服务器名 
			CString strNewServer; 
			AfxParseURLEx(strNewLocation,dwServiceType,strNewServer,strObject,nPort, 
							strUser,strPassword,ICU_NO_ENCODE); 
 
			// 如果不包含服务器名 
			if(strNewServer.IsEmpty()) 
			{ 
				// 增加服务器名 
				CString strTempLocation = strServer; 
				if(strNewLocation.Left(1) != "/") 
					strTempLocation += "/"; 
				strTempLocation += strNewLocation; 
				strNewLocation = strTempLocation; 
			} 
 
			//保存新的地址 
			strURL = strNewLocation; 
 
			::InternetCloseHandle(hURL); 
			::InternetCloseHandle(hConnect); 
			return(LOCATION_MOVED); 
		} 
		else if(dwRet == HTTP_STATUS_REQUEST_TIMEOUT ||  
					dwRet == HTTP_STATUS_GATEWAY_TIMEOUT || 
					dwRet == HTTP_STATUS_NOT_FOUND) 
		{ 
			Sleep(500L); 
			::InternetCloseHandle(hURL); 
			::InternetCloseHandle(hConnect); 
			return(TIMEOUT); 
		} 
		else if(dwRet == HTTP_STATUS_OK) 
		{ 
			// 获取文件 
			BYTE *pbyTempBuffer = *pbyBuffer; 
			DWORD dwTotalBytes = 0; 
			DWORD dwBytesRead; 
			BOOL bOkay = TRUE; 
 
			// 获得大小 
			dwLen = sizeof(szTemp); 
			::HttpQueryInfo(hURL,HTTP_QUERY_CONTENT_LENGTH,szTemp,&dwLen,NULL); 
			dwLen = (DWORD) atol(szTemp); 
 
			// 确保没有获得错误的文件长度 
			if(dwLen <= 0)  
				dwLen = 10000; 
 
			// 循环读取数据 
			while(bOkay) 
			{ 
				// 读取数据 
				bOkay = ::InternetReadFile(hURL,pbyTempBuffer,dwLen,&dwBytesRead); 
 
				// 增加总下载数据量 
				if(bOkay && dwBytesRead > 0 && dwTotalBytes < MAX_INET_BUFFER-1) 
				{ 
					dwTotalBytes += dwBytesRead; 
					pbyTempBuffer += dwBytesRead; 
				} 
				else break; 
			} 
 
			// 以NULL结束缓冲区 
			pbyTempBuffer[0] = '\0'; 
			nLen = dwTotalBytes; 
 
			// 关闭文件 
			::InternetCloseHandle(hURL); 
			::InternetCloseHandle(hConnect); 
 
			return(SUCCESS); 
		} 
	} 
	catch(...) 
	{ 
		// Fatal error, just get out 
		if(hURL)  
			::InternetCloseHandle(hURL); 
 
		if(hConnect) 
			::InternetCloseHandle(hConnect); 
 
		return(UNKNOWN_ERROR); 
	} 
} 
 
// 保存数据 
CInet::RESULTS CInet::SaveFile(CString& strFileName, LPCTSTR lpszDirectory, 
								BYTE *pbyBuffer, int nLen) 
{ 
	CFile fileOut; 
	CFileException ex; 
	CString strTempName = lpszDirectory+strFileName; 
	strTempName = strTempName.SpanExcluding("#"); 
 
	// 创建当地文件 
	if(fileOut.Open(strTempName,CFile::modeCreate|CFile::modeWrite,&ex)) 
	{ 
		// 写入数据 
		fileOut.Write(pbyBuffer,nLen); 
 
		// 关闭文件 
		fileOut.Close(); 
	} 
	else return(BAD_FILENAME); 
 
	return(SUCCESS); 
} 
 
///////////////////// 
// Public operations 
///////////////////// 
 
// Retrieves a page from the web server by calling DoGet().  Also handles 
// redirection to other servers as well as retries. 
CInet::RESULTS CInet::GetPage(CString& strURL, BYTE **pbyBuffer, int& nLen, 
									BOOL bRedirectOkay) 
{ 
	int nRetries = 2; 
	CInet::RESULTS ret; 
 
	do  
	{ 
		// Get the page 
		ret = DoGet(strURL,pbyBuffer,nLen,TRUE); 
	} 
	while(nRetries-- && ((ret == LOCATION_MOVED && bRedirectOkay) ||  
							ret == TIMEOUT)); 
 
	return(ret); 
} 
 
// Retrieves a file from the web server by calling DoGet().  Handles 
// redirection to other web servers as well as retries. 
CInet::RESULTS CInet::GetFile(CString& strURL, BYTE **pbyBuffer, int& nLen) 
{ 
	int nRetries = 2; 
	CInet::RESULTS ret; 
 
	do  
	{ 
		// Get the file 
		ret = DoGet(strURL,pbyBuffer,nLen,FALSE); 
	} 
	while(nRetries-- && (ret == LOCATION_MOVED || ret == TIMEOUT)); 
 
	return(ret); 
} 
 
// Reset the "tie breaker" filename counter used by GenerateUniqueFileName(). 
void CInet::ResetUniqueCount() 
{ 
	m_nUniqueCount = 0; 
} 
 
// 产生一个唯一的文件名，如果有相同的文件名，则在后面增加_x来表示新的文件名 
// x表示是数量，即是第几个同名的 
void CInet::GenerateUniqueFileName(CString& strName, CString& strFileName,  
						MAP_FILES_ARRAY &arrNameMap, BOOL bIsText) 
{ 
	BOOL bFound = FALSE; 
	MAP_FILES entry; 
	CString strTempName = strName; 
	strTempName.MakeLower(); 
	CString strTempFileName; 
 
	// 分离出URL 
	CString strServer,strObject,strUser,strPassword; 
	INTERNET_PORT nPort; 
	DWORD dwServiceType; 
	AfxParseURLEx(strName,dwServiceType,strServer,strObject,nPort,strUser, 
							strPassword,ICU_NO_ENCODE); 
 
	// 获得合法的文件名 
	strFileName = SplitFileName(strObject,CInet::FNAME|CInet::EXT); 
 
	// 是否是一个文件名 
	if(strFileName.IsEmpty()) 
	{ 
		// 如果不是，使用默认的文件名或者错误 
		if(bIsText) 
			strFileName = g_szDefPage; 
		else strFileName = g_szUnknown; 
	} 
	else 
	{ 
		// 如果是HTML文件 
		if(bIsText) 
		{ 
			// 确保文件名以html文件结尾，这样，即使是.asp文件也能够执行 
			CString strExt = SplitFileName(strFileName,CInet::EXT); 
			strExt.MakeLower(); 
 
			if(strExt.Find("#") < 0 && strExt != ".htm" && strExt != ".html") 
			{ 
				strFileName += ".htm"; 
			} 
		} 
	} 
 
	// 获得新的文件名 
	strTempFileName = strFileName; 
	strTempFileName.MakeLower(); 
	strTempName.MakeLower(); 
 
	MAP_FILES *pEntry; 
	CString strPage; 
 
	POSITION pos = arrNameMap.GetStartPosition(); 
 
	// 判断是否存在 
	for(int nEntryNum = 0; nEntryNum < arrNameMap.GetCount(); nEntryNum++) 
	{ 
		arrNameMap.GetNextAssoc(pos,strPage,(CObject *&) pEntry); 
		if(pos == NULL || pEntry == NULL) break; 
 
		// 如果该页已经存在 
		if(strPage == strTempName) 
		{ 
			strName = strPage; 
			strFileName = pEntry->strFileName; 
			return; 
		} 
 
		// 如果找到一个重名的输出文件 
		//则产生一个唯一的 
		if(pEntry->strFileName == strTempFileName) 
		{ 
			// 退出循环 
			bFound = TRUE; 
			break; 
		} 
	} 
 
	// 如果找到重名的，则创建一个新的 
	if(bFound) 
	{ 
		CString strTemp; 
		CString strNewFileName; 
 
		// 寻找后缀名 
		int nIndex = strFileName.Find("."); 
		if(nIndex >= 0) 
			strNewFileName = strFileName.Left(nIndex); 
		else strNewFileName = strFileName; 
 
		// 加入到文件名中 
		strTemp.Format("__%d",++m_nUniqueCount); 
		strNewFileName += strTemp; 
		if(nIndex >= 0) 
			strNewFileName += strFileName.Mid(nIndex); 
 
		// 保存新文件名 
		strFileName = strNewFileName; 
	} 
} 
 
// 分割文件名 
CString CInet::SplitFileName(LPCTSTR lpszPath, int nSplit) 
{ 
	CString strResult; 
 
	char szPath[800],szDrive[800],szFileName[800],szExt[800]; 
	_splitpath(lpszPath,szDrive,szPath,szFileName,szExt); 
 
	if(nSplit & CInet::DRIVE) 
		strResult += szDrive; 
	if(nSplit & CInet::PATH) 
		strResult += szPath; 
	if(nSplit & CInet::FNAME) 
		strResult += szFileName; 
	if(nSplit & CInet::EXT) 
		strResult += szExt; 
 
	return(strResult); 
} 
 
CString CInet::GetErrorText() 
{ 
	CString strError; 
 
	switch(m_dwRet) 
	{ 
		case HTTP_STATUS_MOVED: 
		case HTTP_STATUS_REDIRECT: 
		case HTTP_STATUS_REDIRECT_METHOD: 
			strError = "Redirected, but not found"; 
			break; 
 
		case HTTP_STATUS_REQUEST_TIMEOUT: 
		case HTTP_STATUS_GATEWAY_TIMEOUT: 
			strError = "Timed out on request"; 
			break; 
 
		case HTTP_STATUS_NOT_FOUND: 
		case HTTP_STATUS_BAD_REQUEST: 
		case HTTP_STATUS_GONE: 
			strError = "Page or file not found"; 
			break; 
	 
		case HTTP_STATUS_DENIED: 
		case HTTP_STATUS_PAYMENT_REQ: 
		case HTTP_STATUS_FORBIDDEN: 
		//case HTTP_STATUS_AUTH_REFUSED: 
		//	strError = "Access denied"; 
		//	break; 
 
		case HTTP_STATUS_PROXY_AUTH_REQ: 
			strError = "Proxy authentication required"; 
			break; 
 
		default: 
			strError.Format("WinInet error %d",m_dwRet); 
			break; 
	} 
 
	return(strError); 
}