exampleclientengine.cpp

一个http客户端连接的程序例子

/*
 * ============================================================================
 *  Name     : ExampleClientEngine.cpp
 *  Part of  : HTTP Example
 *  Created  : 11/14/2003 by Forum Nokia
 *  Implementation notes:
 *
 *     
 *  Version  : 1.0
 *  Copyright: Nokia Corporation
 * ============================================================================
 */

#include <avkon.hrh>
#include <aknnotewrappers.h>
#include <uri8.h>
#include <http.h>
#include <chttpformencoder.h>
#include <HttpStringConstants.h>
#include <http\RHTTPTransaction.h>
#include <http\RHTTPSession.h>
#include <http\RHTTPHeaders.h>
#include <ExampleClient.rsg>

#include "ExampleClient.pan"
#include "ExampleClient.hrh"
#include "ExampleClientEngine.h"

// Used user agent for requests
_LIT8(KUserAgent, "SimpleClient 1.0");

// This client accepts all content types.
// (change to e.g. "text/plain" for plain text only)
_LIT8(KAccept, "*/*");


// ----------------------------------------------------------------------------
// CClientEngine::NewL()
//
// Creates instance of CClientEngine.
// ----------------------------------------------------------------------------
CClientEngine* CClientEngine::NewL(MClientObserver& aObserver)
	{
    CClientEngine* self = CClientEngine::NewLC(aObserver);
    CleanupStack::Pop(self);
    return self;
	}


// ----------------------------------------------------------------------------
// CClientEngine::NewLC()
//
// Creates instance of CClientEngine.
// ----------------------------------------------------------------------------
CClientEngine* CClientEngine::NewLC(MClientObserver& aObserver)
	{
    CClientEngine* self = new (ELeave) CClientEngine(aObserver);
    CleanupStack::PushL(self);
    self->ConstructL();
    return self;
	}


// ----------------------------------------------------------------------------
// CClientEngine::CClientEngine()
//
// First phase constructor.
// ----------------------------------------------------------------------------
CClientEngine::CClientEngine(MClientObserver& aObserver)
:	iObserver(aObserver),
	iPostData(NULL),
	iRunning(EFalse)
	{
	}


// ----------------------------------------------------------------------------
// CClientEngine::~CClientEngine()
//
// Destructor.
// ----------------------------------------------------------------------------
CClientEngine::~CClientEngine()
	{
	iSession.Close();

	delete iPostData;
	iPostData = NULL;
	}


// ----------------------------------------------------------------------------
// CClientEngine::ConstructL()
//
// Second phase construction.
// ----------------------------------------------------------------------------
void CClientEngine::ConstructL()
	{
	// Open RHTTPSession with default protocol ("HTTP/TCP")
	TRAPD(err, iSession.OpenL());
	if(err != KErrNone) {
		// Most common error; no access point configured, and session creation
		// leaves with KErrNotFound.
		_LIT(KErrMsg,
			"Cannot create session. Is internet access point configured?");
		_LIT(KExitingApp, "Exiting app.");
		CEikonEnv::Static()->InfoWinL(KErrMsg, KExitingApp);
		User::Leave(err);
	}

	// Install this class as the callback for authentication requests. When 
	// page requires authentication the framework calls GetCredentialsL to get 
	// user name and password.
	InstallAuthenticationL(iSession);
	}


// ----------------------------------------------------------------------------
// CClientEngine::SetHeaderL()
//
// Used to set header value to HTTP request
// ----------------------------------------------------------------------------
void CClientEngine::SetHeaderL(RHTTPHeaders aHeaders, 
							 TInt aHdrField, 
							 const TDesC8& aHdrValue)
	{
	RStringF valStr = iSession.StringPool().OpenFStringL(aHdrValue);
	CleanupClosePushL(valStr);
	THTTPHdrVal val(valStr);
	aHeaders.SetFieldL(iSession.StringPool().StringF(aHdrField,
		RHTTPSession::GetTable()), val);
	CleanupStack::PopAndDestroy(); // valStr
	}


// ----------------------------------------------------------------------------
// CClientEngine::IssueHTTPGetL()
//
// Start a new HTTP GET transaction.
// ----------------------------------------------------------------------------
void CClientEngine::IssueHTTPGetL(const TDesC8& aUri)
	{
	// Parse string to URI (as defined in RFC2396)
	TUriParser8 uri;
	uri.Parse(aUri);

	// Get request method string for HTTP GET
	RStringF method = iSession.StringPool().StringF(HTTP::EGET,
		RHTTPSession::GetTable());

	// Open transaction with previous method and parsed uri. This class will
	// receive transaction events in MHFRunL and MHFRunError.
	iTransaction = iSession.OpenTransactionL(uri, *this, method);

	// Set headers for request; user agent and accepted content type
	RHTTPHeaders hdr = iTransaction.Request().GetHeaderCollection();
	SetHeaderL(hdr, HTTP::EUserAgent, KUserAgent);
	SetHeaderL(hdr, HTTP::EAccept, KAccept);

	// Submit the transaction. After this the framework will give transaction
	// events via MHFRunL and MHFRunError.
	iTransaction.SubmitL();

	iRunning = ETrue;
	_LIT(KConnecting,"Connecting...");
	iObserver.ClientEvent(KConnecting);
	}


// ----------------------------------------------------------------------------
// CClientEngine::IssueHTTPPostL()
//
// Start a new HTTP POST transaction.
// ----------------------------------------------------------------------------
void CClientEngine::IssueHTTPPostL(const TDesC8& aUri, 
								 const TDesC8& aContentType, 
								 const TDesC8& aBody) 
	{
	// Parse string to URI
	TUriParser8 uri; 
	uri.Parse(aUri);

	// Copy data to be posted into member variable; iPostData is used later in
	// methods inherited from MHTTPDataSupplier.
	delete iPostData;
	iPostData = aBody.AllocL();

	// Get request method string for HTTP POST
	RStringF method = iSession.StringPool().StringF(HTTP::EPOST,
		RHTTPSession::GetTable());

	// Open transaction with previous method and parsed uri. This class will 
	// receive transaction events in MHFRunL and MHFRunError.
	iTransaction = iSession.OpenTransactionL(uri, *this, method);
	
	// Set headers for request; user agent, accepted content type and body's 
	// content type.
	RHTTPHeaders hdr = iTransaction.Request().GetHeaderCollection();
	SetHeaderL(hdr, HTTP::EUserAgent, KUserAgent);
	SetHeaderL(hdr, HTTP::EAccept, KAccept);
	SetHeaderL(hdr, HTTP::EContentType, aContentType);

	// Set this class as an data supplier. Inherited MHTTPDataSupplier methods
	// are called when framework needs to send body data.
	MHTTPDataSupplier* dataSupplier = this;
	iTransaction.Request().SetBody(*dataSupplier);

	// Submit the transaction. After this the framework will give transaction
	// events via MHFRunL and MHFRunError.
	iTransaction.SubmitL();

	iRunning = ETrue;
	_LIT(KConnecting,"Connecting...");
	iObserver.ClientEvent(KConnecting);
	}

// ----------------------------------------------------------------------------
// CClientEngine::CancelTransaction()
//
// Cancels currently running transaction and frees resources related to it.
// ----------------------------------------------------------------------------
void CClientEngine::CancelTransaction()
	{
	if(!iRunning) 
		return;

	// Close() also cancels transaction (Cancel() can also be used but 
	// resources allocated by transaction must be still freed with Close())
	iTransaction.Close();

	// Not running anymore
	iRunning = EFalse;
	_LIT(KTransactionCancelled, "Transaction cancelled");
	iObserver.ClientEvent(KTransactionCancelled);
	}


// ----------------------------------------------------------------------------
// CClientEngine::MHFRunL()
//
// Inherited from MHTTPTransactionCallback
// Called by framework to pass transaction events.
// ----------------------------------------------------------------------------
void CClientEngine::MHFRunL(RHTTPTransaction aTransaction, 
						  const THTTPEvent& aEvent)
	{

	switch (aEvent.iStatus) 
	{
	case THTTPEvent::EGotResponseHeaders:
		{
		// HTTP response headers have been received. Use
		// aTransaction.Response() to get the response. However, it's not
		// necessary to do anything with the response when this event occurs.

		// Get HTTP status code from header (e.g. 200)
		RHTTPResponse resp = aTransaction.Response();
		TInt status = resp.StatusCode();