构建CHttpSession 类来实现网页数据的请求

最近实现了一个简单的CHttpSession类，用来请求制定URL的网页，支持POST传送方式和cookie机制。当然使用了CInternetSession，CHttpConnection和CHttpFile类，但我没有继承CInternetSession类。

POST支持的函数如下：

 
 

  BOOL CHttpSession::SendData(CHttpFile
  *
   pFile,LPCSTR pszPostForm
  /**/
  /*=NULL*/
  )
  ...
  {
    ASSERT(pFile!=NULL);
    BOOL bResult=TRUE;
    if(pszPostForm!=NULL)
    ...{
        CString strFormData(pszPostForm);    
        //post data
        CString strHeaders = _T("Content-Type: application/x-www-form-urlencoded"); 
        // URL-encoded form variables - 
        bResult=pFile->SendRequest(strHeaders, 
            (LPVOID)(LPCTSTR)strFormData, strFormData.GetLength());
        TRACE("post data:%s/n",pszPostForm);
    }
    else
    ...{
        bResult=pFile->SendRequest();
    }
    CString strReqHead,strRepHead;
    if(bResult)
   ...{
        //#ifdef _DEBUG
        DWORD dw=1;                    
        pFile->QueryInfo(HTTP_QUERY_RAW_HEADERS_CRLF,strRepHead);
        pFile->QueryInfoStatusCode(_nStatus);
        BOOL bResult=TRUE;
        bResult=pFile->QueryInfo(HTTP_QUERY_FLAG_REQUEST_HEADERS|HTTP_QUERY_RAW_HEADERS_CRLF,
            strReqHead.GetBufferSetLength(dw),&dw,0);
        if(!bResult && GetLastError()==ERROR_INSUFFICIENT_BUFFER)
        ...{
            bResult=pFile->QueryInfo(HTTP_QUERY_FLAG_REQUEST_HEADERS|HTTP_QUERY_RAW_HEADERS_CRLF,
                strReqHead.GetBufferSetLength(dw),&dw,0);
        }
        //szBuffer[dw]='/0';
        //strReqHead=CString(szBuffer);
        //int nLen=strReqHead.ReverseFind('/n')+1;
        strReqHead.ReleaseBuffer(dw);
        //CString strTmp;
        //strTmp.Format("http req head:/n%s/n/n http rep head:/n%s",strReqHead,strRepHead);
        //TRACE(strTmp);
        //#endif
        TRACE("http req head:/n%s/n",strReqHead);
        TRACE("http rep head:/n%s/n",strRepHead);
        _strRepHead=strRepHead;
        _strReqHead=strReqHead;
    }
    else
    ...{
        TRACE("send req error!/n");
    }
    return bResult;    
}
URL的form格式编码是在网上搜到的；
 

设置COOKIE相对简单些，直接调用CInternetSession类中的函数实现：

 

  
  void
   CHttpSession::GetCookie(CString
  &
   strCookie,LPCTSTR pszUrl)

  ...
  {
    ASSERT(AfxIsValidString(pszUrl));
    //cookie叠加
    if(IsSameSite(_strUrl,pszUrl))
    ...{
        TRACE("same site for cookie!/n");
    }

    //得到存储的cookie
    strCookie=_T("");
    DWORD dwCookieLen=CInternetSession::GetCookieLength(pszUrl,"");
    if(dwCookieLen>0)
    ...{
        BOOL bRet=CInternetSession::GetCookie(pszUrl,
            "",
            strCookie);
        //strCookie.ReleaseBuffer(2*dwCookieLen/sizeof(TCHAR));
        TRACE("cookie=%s/n",strCookie);
        if(!bRet)
        ...{
            strCookie=_T("");
            TRACE("得到cookie失败!/n");
        }
    }
    _strUrl=CString(pszUrl);


}
 

**类的引用格式如下：
** CHttpSession httpSession;
httpSession.SetStatusWnd(GetDlgItem(IDC_EDIT1)); //指定接收消息的窗口
try{
httpSession.SetHead(_T("Accept-Language"),_T("zh-cn"));
httpSession.SetHead(_T("pragma"),_T("by luo31"));
httpSession.SetHead(_T("Connection"),_T("Keep-Alive"));
httpSession.SetHead(_T("Referer"),_T(www.sohu.com/login.html));

  httpSession.SetPost(_T("UserID"),_T("luo31"));
httpSession.SetPost(_T("Password"),_T("iloveu"));
httpSession.SetPost(_T("confirm"),_T("确 定"));
httpSession.StartPostReq("www.sohu.com/login.html/login.asp"); 
//AfxMessageBox(httpSession.GetReqHead());
httpSession.EndReq();

  //go session
httpSession.SetHead(_T("Accept-Language"),_T("zh-cn"));
httpSession.SetHead(_T("pragma"),_T("by luo31"));
httpSession.SetHead(_T("Connection"),_T("Keep-Alive"));
httpSession.SetHead(_T("Referer"),_T("www.sohu.com/login.html/main.asp"));

  httpSession.StartGetReq("www.sohu.com/login.html/mail.asp"); 
httpSession.SaveHtmlFile("mail.htm"); //存储目标文件
//AfxMessageBox(httpSession.GetReqHead());
httpSession.EndReq();  

//ok
AfxMessageBox("ok!");
}
catch(CInternetException* e)
{
e->ReportError();
e->Delete();
}