httpexampleengine.cpp

symbian 平台下完整的http网络通讯例子。

/**
*
* @brief Definition of CHTTPExampleEngine
*
* Copyright (c) EMCC Software Ltd 2003
* @version 1.0
*/

// INCLUDE FILES

// Class include
#include "HTTPExampleEngine.h"

// System includes
#include <chttpformencoder.h>		// CHTTPFormEncoder
#include <httpstringconstants.h>	// HTTP string table
#include <rhttpheaders.h>			// RHTTPHeaders

// User includes
#include "HTTPExample.hrh"			// EMaxNameLength

// CONSTANTS
// HTTP header values
_LIT8(KUserAgent, "HTTPExample (1.0)");	// Name of this client app
_LIT8(KAccept, "text/*");				// Accept any (but only) text content
_LIT8(KPostParamName, "NAME");			// Name of the parameter sent in a POST request
_LIT8(KPostContentType, "text/plain");	// Content type sent in a POST request

// URL for POST request.
//_LIT8(KPostUri, "http://cgi.www.emccsoft.com/cgi-bin/www.emccsoft.com/post.pl");
_LIT8(KPostUri, "http://www.magpiemobile.com/cgi-bin/book_post.cgi");


// ================= MEMBER FUNCTIONS =======================

/**
* 2-phase constructor
*
* @param aObserver An observer of this engine (e.g. the UI)
*/
CHTTPExampleEngine* CHTTPExampleEngine::NewL(MHTTPExampleEngineObserver& aObserver)
	{
	CHTTPExampleEngine* self = new (ELeave) CHTTPExampleEngine(aObserver);
	CleanupStack::PushL(self);
	self->ConstructL();
	CleanupStack::Pop(self);
	return self;
	}

/**
* C++ constructor
*
* @param aObserver An observer of this engine (e.g. the UI)
*/
CHTTPExampleEngine::CHTTPExampleEngine(MHTTPExampleEngineObserver& aObserver)
: iObserver(aObserver)
	{
	}

/**
* 2nd-phase constructor
*/
void CHTTPExampleEngine::ConstructL()
	{
	// Open the RHTTPSession
	iSession.OpenL();

	// Construct the form encoder
	iFormEncoder = CHTTPFormEncoder::NewL();
	}

/**
* C++ destructor
*/
CHTTPExampleEngine::~CHTTPExampleEngine()
	{
	// Close session
	iSession.Close();	// Will also close any open transactions
	delete iResponseBuffer;
	delete iFormEncoder;
    delete iUri;
	}

/**
* Override of pure virtual method in MHTTPTransactionCallback.
* Called to report progress by a currently outstanding transaction.
*
* @param aTransaction The transaction reporting progress
* @param aEvent The event being notified
*/
void CHTTPExampleEngine::MHFRunL(RHTTPTransaction aTransaction, const THTTPEvent& aEvent)
	{
	switch (aEvent.iStatus)
		{
		case THTTPEvent::EGotResponseHeaders:
			{
			// HTTP response headers have been received.
			// Pass status information to observer.
			RHTTPResponse resp = aTransaction.Response();

			// Get status code
			TInt statusCode = resp.StatusCode();

			// Get status text
			RStringF statusStr = resp.StatusText();
			HBufC* statusBuf = HBufC::NewLC(statusStr.DesC().Length());
			statusBuf->Des().Copy(statusStr.DesC());

			// Inform observer
			iObserver.ResponseStatusL(statusCode, *statusBuf);

			CleanupStack::PopAndDestroy(statusBuf);
			}
			break;


		case THTTPEvent::EGotResponseBodyData:
			{
			// Get text of response body
			MHTTPDataSupplier* dataSupplier = aTransaction.Response().Body();
			TPtrC8 ptr;
			dataSupplier->GetNextDataPart(ptr);

			// Convert to 16-bit descriptor
			HBufC* buf = HBufC::NewLC(ptr.Length());
			buf->Des().Copy(ptr);

			// Append to iResponseBuffer
			if (!iResponseBuffer)
				{
				iResponseBuffer = buf->AllocL();
				}
			else
				{
				iResponseBuffer = iResponseBuffer->ReAllocL(iResponseBuffer->Length() + buf->Length());
				iResponseBuffer->Des().Append(*buf);
				}

			// Release buf
			CleanupStack::PopAndDestroy(buf);

			// Release the body data
			dataSupplier->ReleaseData();
			}
			break;

		case THTTPEvent::EResponseComplete:
			{
			// Pass the response buffer by reference to the observer
			iObserver.ResponseReceivedL(*iResponseBuffer);
			}
			break;
		}
	}

/**
*/
TInt CHTTPExampleEngine::MHFRunError(TInt aError, RHTTPTransaction /*aTransaction*/, const THTTPEvent& /*aEvent*/)
	{
	return aError;
	}


/**
* Initiate a GET request
*
* @param aUri The URI to get
*/
void CHTTPExampleEngine::GetRequestL(const TDesC& aUri)
	{
	// Parse the URI
	ParseUriL(aUri);

	// Create the transaction
	iTransaction = iSession.OpenTransactionL(iUriParser, *this,
		iSession.StringPool().StringF(HTTP::EGET, RHTTPSession::GetTable()));

	// Set transaction headers
	RHTTPHeaders headers = iTransaction.Request().GetHeaderCollection();
	AddHeaderL(headers, HTTP::EUserAgent, KUserAgent);
	AddHeaderL(headers, HTTP::EAccept, KAccept);

	// Submit the request
	iTransaction.SubmitL();
	}


/**
* Initiate a POST request
*
* @param aName The user's name
*/
void CHTTPExampleEngine::PostRequestL(const TDesC& aName)
	{
	// Build form encoder
	// Start by removing any previous content
	delete iFormEncoder;
	iFormEncoder = NULL;
	iFormEncoder = CHTTPFormEncoder::NewL();
	TBuf8<EMaxNameLength> buf8;
	buf8.Copy(aName);
	iFormEncoder->AddFieldL(KPostParamName, buf8);

	// Create transaction
	iUriParser.Parse(KPostUri);
	iTransaction = iSession.OpenTransactionL(iUriParser, *this,
		iSession.StringPool().StringF(HTTP::EPOST, RHTTPSession::GetTable()));

	// Set transaction headers
	RHTTPHeaders headers = iTransaction.Request().GetHeaderCollection();
	AddHeaderL(headers, HTTP::EUserAgent, KUserAgent);
	AddHeaderL(headers, HTTP::EAccept, KAccept);
	AddHeaderL(headers, HTTP::EContentType, KPostContentType);

	// Set the form encoder as the data supplier
	iTransaction.Request().SetBody(*iFormEncoder);

	// Submit the request
	iTransaction.SubmitL();
	}


//
// Utility methods
//

/**
* Parse a URI
*
* @param aUri The URI to be parsed
*/
void CHTTPExampleEngine::ParseUriL(const TDesC& aUri)
	{
	// Convert the URI to an 8-bit descriptor
	// then set iUriParser to point at it
	delete iUri;
	iUri = NULL;
	iUri = HBufC8::NewL(aUri.Length());
	iUri->Des().Copy(aUri);
	User::LeaveIfError(iUriParser.Parse(*iUri));
	}


/**
* Add a header to a header set
*
* @param aHeaders The header set to be modified
* @param aHeaderField The name of the header to be added
* @param aHeaderValue The value for the header to be added
*/
void CHTTPExampleEngine::AddHeaderL(RHTTPHeaders aHeaders, TInt aHeaderField, const TDesC8& aHeaderValue)
	{
	RStringPool stringPool = iSession.StringPool();
	RStringF valStr = stringPool.OpenFStringL(aHeaderValue);
	THTTPHdrVal headerVal(valStr);
	aHeaders.SetFieldL(stringPool.StringF(aHeaderField, RHTTPSession::GetTable()), headerVal);
	valStr.Close();
	}


/**
* Cancel any outstanding transaction
*/
void CHTTPExampleEngine::Cancel()
	{
	iTransaction.Cancel();
	}