downloadfile.cpp

Symbian OS C++ 手机应用开发 Series 60应用程序开发 symbian

/*
 * downloadfile.cpp
 *
 *  Created on: 2009-4-27
 *      Author: Administrator
 */

#ifndef DOWNLOADFILE_H_
#define DOWNLOADFILE_H_
#include "downloadfile.h" 


void CDownLoadEngine::GetRequestL(const TDesC8& aUri)
	{
	
	 ParseUriL(aUri);//对URL地址进行分析 
	
	 // Create the transaction
	 iTransaction = iSession.OpenTransactionL(iUriParser, *this,
	  iSession.StringPool().StringF(HTTP::EGET, RHTTPSession::GetTable()));
	
	 RHTTPHeaders headers = iTransaction.Request().GetHeaderCollection();
	
	//添加HTTP请求消息头
	
	 AddHeaderL(headers, HTTP::EUserAgent, KUserAgent);
	 AddHeaderL(headers, HTTP::EAccept, KAccept);
	 // Set transaction headers
	 if (0 != m_recv_bytes)
		 {
		  TBuf8 <20> aBufLength;
		  aBufLength.SetLength(0);
		  aBufLength.Append(KRange);
		  aBufLength.AppendNum(m_recv_bytes);
		  aBufLength.Append(_L("-"));//这里一定要注意了。如果是断点下载一定要加上这个，我可被这个害死了
		  AddHeaderL(headers, HTTP::ERange,aBufLength);
		 }
	
	 // Submit the request
	 iTransaction.SubmitL();
	}

/**---------------------------------------------------------------------------
 *  文件名       : DemoClass.cpp
 *  功  能       : 实现URL连接
 *  作  者       : 洪文彬
 *  日  期       : 2009/4/27
 **---------------------------------------------------------------------------
*/
void CDownLoadEngine::ParseUriL(const TDesC8& 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));
		
	}
	
//这个函数时处理从internet返回的消息
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();
	}

void CDownLoadEngine::MHFRunL(RHTTPTransaction aTransaction, const THTTPEvent& aEvent)
	{
	 switch (aEvent.iStatus)
	 {
	 case THTTPEvent::EGotResponseHeaders://返回的是消息头
	
	//这个样说明一下之前那个基于RSock的话需要自己去判断那里是消息头那里是Boday
	
	//在这个例子中框架可以给你去判断
		  {
		
		   THTTPHdrVal aHeaderValue;
			RHTTPResponse resp = aTransaction.Response();
			RHTTPHeaders aHeaders = resp.GetHeaderCollection();
		   TRAPD(error,GetHeaderL (aHeaders, _L8("Content-Length"), aHeaderValue ));
		   m_total_bytes = aHeaderValue.Int();
		   m_total_bytes += m_recv_bytes;
		   
		
		  }
	  break;
	
	
	 case THTTPEvent::EGotResponseBodyData:
	
	//获取消息Body后要将其写入本地文件中
		  {
		   MHTTPDataSupplier* dataSupplier = aTransaction.Response().Body();
		   TPtrC8 ptr;
		   dataSupplier->GetNextDataPart(ptr);
		
		   HBufC* buf = HBufC::NewLC(ptr.Length());
		   buf->Des().Copy(ptr);
		   HBufC8* aBufTmp;
		
		
		   // Append to iResponseBuffer
		   if (!iResponseBuffer)
		   {
			iResponseBuffer = buf->AllocL();
			aBufTmp = HBufC8::NewL(iResponseBuffer->Des().Length());
		
			aBufTmp ->Des().Copy(iResponseBuffer->Des());
			RecvNotify(*aBufTmp);
			
		   }
		   else
		   {
		//     iResponseBuffer = iResponseBuffer->ReAllocL(iResponseBuffer->Length() + buf->Length());
		//     iResponseBuffer->Des().Append(*buf);
			aBufTmp = HBufC8::NewL(buf->Des().Length());
		
			aBufTmp ->Des().Copy(buf->Des());
			RecvNotify(*aBufTmp);
		   }
		
		   CleanupStack::PopAndDestroy(buf);
		   //CleanupStack::PopAndDestroy(aBufTmp);
		   dataSupplier->ReleaseData();
		  }
	  break;
	
	 case THTTPEvent::EResponseComplete:
	
	//下载完毕
		  {
		   TInt aIndexofTmp;
		   aIndexofTmp = iFileName.Find(_L(".tmp"));
		   iFileName.Delete(aIndexofTmp,4);
		   iFile.Rename(iFileName);
		
		  }
	  break;
	 }
}