http://www.codeproject.com/kb/library/lyoulhttpclient.aspx
Download CHttpClient source files - 72.9 KB
Download CHttpClient demo project - 109.9 KB
Download CHttpClient help file - 445.9 KB
Download CHttpClient COM Edition source files - 141.6 KB
Download CHttpClient COM Edition demo project - 55.4 KB
Download CHttpClient COM Edition help file - 218.3 KB
Download CHttpClient COM Edition compiled binary - 77.9 KB
CHttpClient is a helper class using WinInet API. The purpose of this class is to help you interact with a HTTP web server. The class design goal is as follows:
Easy to use. As many flexibilities as possible. Strict error handling.I will briefly show you how to use this class. All detailed description has been documented in the attached help file.
In your project, include the following files:
RyeolException.h RyeolException.cpp RyeolHttpClient.h RyeolHttpClient.cpp SafeInt.hppIn your stdafx.h file, add the following line:
Collapse | #include "RyeolHttpClient.h"Note: The namespace and file names have been changed. If you use the previous version of the CHttpClient, you need to update as follows:
LyoulException.h --> RyeolException.h LyoulException.cpp --> RyeolException.cpp LyoulHttpClient.h --> RyeolHttpClient.h LyoulHttpClient.cpp --> RyeolHttpClient.cpp #include "LyoulHttpClient.h" --> #include "RyeolHttpClient.h" using namespace Lyoul --> using namespace RyeolCHttpClient supports RequestGet method which sends a request using HTTP GET:
Collapse | // Retrieves the resource specified by the szUrl using HTTP GET request. // szUrl [in] A HTTP URL. // bUseCache [in] Specifies whether to use cache. CHttpResponse * CHttpClient::RequestGet (PCSZ szUrl, BOOL bUseCache = FALSE) throw (Exception &) ;The following code demonstrates the basic usage of the RequestGet method:
Collapse | using namespace Ryeol ; CHttpClient objHttpReq ; CHttpResponse * pobjHttpRes = NULL ; try { // Initialize the User Agent objHttpReq.SetInternet (_T ("My User Agent v1.0")) ; // Specifies whether to use UTF-8 encoding. // (This uses ANSI encoding) // Default is FALSE objHttpReq.SetUseUtf8 (FALSE) ; // Specifies a code page for ANSI strings. // (This uses Korean) // Default is CP_ACP objHttpReq.SetAnsiCodePage (949) ; // Add user's custom HTTP headers objHttpReq.AddHeader (_T ("Ryeol-Magic"), _T ("My Magic Header")) ; objHttpReq.AddHeader (_T ("User-Magic"), _T ("User's Magic Header")) ; // Add user's parameters objHttpReq.AddParam (_T ("where"), _T ("nexearch")) ; objHttpReq.AddParam (_T ("frm"), _T ("t1")) ; objHttpReq.AddParam (_T ("query"), _T ("%C3%D6%C1%F6%BF%EC"), CHttpClient::ParamEncodedValue) ; // Send a request pobjHttpRes = objHttpReq.RequestGet (_T ("http://search.naver.com/search.naver")) ; ... // Place codes to handle the returned CHttpResponse object. } catch (httpclientexception & e) { ... // Place exception handling codes here. }The HTTP POST method is used in two ways. One is to post simple text, the other is to upload files. To post simple text, CHttpClient provides BeginPost method.
Collapse | // Starts a new HTTP POST request // szUrl [in] A HTTP URL. // bUseCache [in] Specifies whether to use cache. void CHttpClient::BeginPost (PCSZ szUrl, BOOL bUseCache = FALSE) throw (Exception &) ;The following code demonstrates the basic usage of the BeginPost method:
Collapse | using namespace Ryeol ; CHttpClient objHttpReq ; CHttpResponse * pobjHttpRes = NULL ; try { // Initialize the User Agent objHttpReq.SetInternet (_T ("My User Agent v1.0")) ; // Add user's custom HTTP headers objHttpReq.AddHeader (_T ("Ryeol-Magic"), _T ("My Magic Header")) ; objHttpReq.AddHeader (_T ("User-Magic"), _T ("User's Magic Header")) ; // Add user's parameters objHttpReq.AddParam (_T ("st"), _T ("kw")) ; objHttpReq.AddParam (_T ("target"), _T ("WinInet")) ; // Start a new request objHttpReq.BeginPost (_T ("http://www.codeproject.com/info/search.asp")) ; // Specifies the number of bytes to send when the Proceed method is called. const DWORD cbProceed = 1024 ; // 1K do { ... // Place codes to report progress information to user. } while ( !(pobjHttpRes = objHttpReq.Proceed (cbProceed)) ) ; ... // Place codes to handle the returned CHttpResponse object. } catch (httpclientexception & e) { ... // Place exception handling codes here. }To upload file, CHttpClient provides BeginUpload method.
Collapse | // Starts a new UPLOAD request // szUrl [in] A HTTP URL. // bUseCache [in] Specifies whether to use cache. void CHttpClient::BeginUpload (PCSZ szUrl, BOOL bUseCache = FALSE) throw (Exception &) ;The following code demonstrates the basic usage of the BeginUpload method:
Collapse | using namespace Ryeol ; CHttpClient objHttpReq ; CHttpResponse * pobjHttpRes = NULL ; try { // Initialize the User Agent objHttpReq.SetInternet (_T ("My User Agent v1.0")) ; // Add user's custom HTTP headers objHttpReq.AddHeader (_T ("Ryeol-Magic"), _T ("My Magic Header")) ; objHttpReq.AddHeader (_T ("User-Magic"), _T ("User's Magic Header")) ; // Add user's parameters objHttpReq.AddParam (_T ("nohtml"), _T ("1")) ; objHttpReq.AddParam (_T ("title"), _T ("The K-NET photo")) ; objHttpReq.AddParam (_T ("content"), _T ("A photo of the K-NET")) ; // Specifies a file to upload objHttpReq.AddParam (_T ("ufile01"), _T ("D://My Photo//K-NET//photo1.jpg"), CHttpClient::ParamFile) ; // Start a new request objHttpReq.BeginUpload (_T ("http://club.hooriza.com") _T ("/cmd/box.html?clubid=1&boxid=53&action=store&link=")) ; // Specifies the number of bytes to send when the Proceed method is called. const DWORD cbProceed = 1024 ; // 1K do { ... // Place codes to report progress information to user. } while ( !(pobjHttpRes = objHttpReq.Proceed (cbProceed)) ) ; ... // Place codes to handle the returned CHttpResponse object. } catch (httpclientexception && e) { ... // Place exception handling codes here. }When you send a request using CHttpClient, all the methods will return CHttpResponse object. CHttpResponse represents the response returned by a HTTP web server. CHttpResponse provides the following methods:
Collapse | // Returns the number of headers of which name is the szName DWORD CHttpResponse::GetHeaderCount (PCSZ szName) throw (Exception &) ; // Returns the header of which name is the szName PCSZ CHttpResponse::GetHeader (PCSZ szName, DWORD nIdx = 0) throw (Exception &) ; // Returns the HTTP status code returned by a HTTP server DWORD CHttpResponse::GetStatus (void) throw (Exception &) ; // Returns the HTTP status text returned by a HTTP server PCSZ CHttpResponse::GetStatusText (void) throw (Exception &) ; // Retrieves the length of the content returned by a HTTP server BOOL CHttpResponse::GetContentLength (DWORD & cbContLen) throw (Exception &) ; // Reads the content returned by a HTTP server DWORD CHttpResponse::ReadContent (BYTE * pbyBuff, DWORD cbBuff) throw (Exception &) ;The following code demonstrates the basic usage of the CHttpResponse object:
Collapse | using namespace Ryeol ; CHttpResponse * pobjHttpRes = NULL ; try { // Get the CHttpResponse object pobjHttpRes = ... ; // Reads the HTTP status code _tprintf (_T ("%u"), pobjHttpRes->GetStatus ()) ; // Reads the HTTP status text _tprintf (_T (" %s/n"), pobjHttpRes->GetStatusText ()) ; // Reads HTTP headers using an array of header names static LPCTSTR szHeaders[] = { _T ("Server"), _T ("Date"), _T ("X-Powered-By"), _T ("Content-Length"), _T ("Set-Cookie") , _T ("Expires"), _T ("Cache-control"), _T ("Connection"), _T ("Transfer-Encoding") , _T ("Content-Type") } ; LPCTSTR szHeader ; for (size_t i = 0; i < sizeof (szHeaders) / sizeof (LPCTSTR); i++) { if ( szHeader = pobjHttpRes->GetHeader (szHeaders[i]) ) _tprintf (_T ("%s: %s/n"), szHeaders[i], szHeader) ; else // If the header is not found.. _tprintf (_T ("'%s' header does not exist../n"), szHeaders[i]) ; } _tprintf (_T ("/n")) ; // Checks whether the returned stream is a text BOOL bIsText = FALSE ; if ( szHeader = pobjHttpRes->GetHeader (_T ("Content-Type")) ) bIsText = (0 == ::_tcsncicmp (szHeader, _T ("text/"), 5)) ; // Reads the length of the stream DWORD dwContSize ; // If the length is not specified if ( !pobjHttpRes->GetContentLength (dwContSize) ) dwContSize = 0 ; const DWORD cbBuff = 1024 * 10 ; BYTE byBuff[cbBuff] ; DWORD dwRead ; size_t cbTotal = 0 ; // Reads the data stream returned by the HTTP server. while ( dwRead = pobjHttpRes->ReadContent (byBuff, cbBuff - 1) ) { cbTotal += dwRead ; if ( bIsText ) { byBuff[dwRead] = '/0' ; printf ("%s", reinterpret_cast<LPCSTR> (byBuff)) ; } } if ( !bIsText ) _tprintf (_T ("%u bytes skipped../n"), cbTotal) ; } catch (httpclientexception & e) { ... // Place exception handling codes here. } delete pobjHttpRes ; pobjHttpRes = NULL ;When an error occurs, httpclientexception object is thrown:
Collapse | class httpclientexception { public: // Returns the last error code. // The error codes is defined in RyeolHttpClient.h DWORD LastError (void) const throw () ; // Returns the last error message. LPCTSTR errmsg (void) const throw () ; // Returns the last win32 error code retrieved by // using ::GetLastError when an error occurred. DWORD Win32LastError (void) const throw () ; } ;Before throwing an exception, most methods restore their internal states (all or nothing like transaction). But if you call BeginPost or BeginUpload method, the POST context is automatically canceled. You should write the following try-catch block to handle the exception:
Collapse | using namespace Ryeol ; try { ... // Place codes which throw a httpclientexception exception } catch (httpclientexception & e) { _tprintf (_T ("An error has been occured/n")) ; _tprintf (_T ("ErrCode: 0x%x/n"), e.LastError ()) ; _tprintf (_T ("ErrMsg: %s/n"), e.errmsg ()) ; if ( e.Win32LastError () != NO_ERROR ) { TCHAR szErrMsg[512] ; GetWinInetErrMsg (szErrMsg, 512, e.Win32LastError ()) ; _tprintf (_T ("Win32ErrCode: 0x%x/n"), e.Win32LastError ()) ; _tprintf (_T ("Win32ErrMsg: %s/n"), szErrMsg) ; } }If you call BeginPost or BeginUpload method, you can retrieve the progress information using the Query method:
Collapse | // Queries progress information of the current POST context // objPostStat [out] A CHttpPostStat object. void CHttpClient::Query (CHttpPostStat & objPostStat) throw () ;CHttpPostStat represents the progress information of the current POST context. The following code demonstrates the basic usage of the CHttpPostStat object:
Collapse | using namespace Ryeol ; CHttpClient objHttpReq ; CHttpResponse * pobjHttpRes = NULL ; size_t cbProceed = 1024 ; // 1k try { ... ; // Intialize the CHttpClient object // Starts a new POST request objHttpReq.BeginPost (...) or objHttpReq.BeginUpload (...) ; // Displays progress information CHttpPostStat objPostStat ; do { // Retrieves progress information objHttpReq.Query (objPostStat) ; _tprintf (_T ("/nPost in progress... %2u/%2u/n") , objPostStat.PostedCount () // The number of posted parameters , objPostStat.TotalCount ()) ; // The total number of parameters _tprintf (_T ("%s: %10u/%10u %10u/%10u %10u/%10u/n") // The name of the current parameter , objPostStat.CurrParam () // The number of posted bytes of the current parameter , objPostStat.CurrParamPostedByte () // The total number of bytes of the current parameter , objPostStat.CurrParamTotalByte () // The number of posted bytes of the request , objPostStat.PostedByte () // The total number of bytes of the request , objPostStat.TotalByte () // The actual number of posted bytes of the request , objPostStat.ActualPostedByte () // The actual total number of bytes of the request , objPostStat.ActualTotalByte ()) ; // If the current parameter is a file parameter, // displays the file path if ( objPostStat.CurrParamIsFile () ) _tprintf (_T ("-->%s/n") , objPostStat.CurrFile ()) ; // Sends the number of bytes specified by cbProceed to the server } while ( !(pobjHttpRes = objHttpReq.Proceed (cbProceed)) ) ; ... ; // Handles the returned CHttpResponse object } catch (httpclientexception & e) { ... // Place exception handling codes here. }CHttpClient COM Edition is the component version of CHttpClient. I won't explain here how to use it because it is similar to CHttpClient. You can refer to the attached examples and the help file of CHttpClient COM edition. If you want to use CHttpClient COM edition, you need to install RyeolHttpClient2.dll. Because it is a COM DLL, you have to register it by using the regsvr32.exe program. You can install it anywhere you want provided you don't distribute it. But if you want to distribute it, I recommend that you install it in the %WINDOWS%System32 folder and do not remove it even if your program is uninstalled.
