c/c++ socket發送http請求訪問網站

這幾天課比較少，校園網上網要認證才能上網，每次必須輸入學號密碼，為了方便，寫了一個自動登錄以及如果在線，登錄自服務系統強制下線的小工具。

強制下線思路：獲取sessionID----------》獲取驗證碼圖片------------》AspriseOCRLib識別驗證碼---------------》MD5加密、url Encode----------------》登錄自服務系統----------------》強制下線---------------------》退出登錄。

 

需要注意的問題：

1、獲取驗證碼時，發送完請求應該Sleep 1秒，等待接收完畢，再調用recv讀緩沖區，否則可能圖片為接受完。

2、登錄請求后需要延時，等待服務器把登錄狀態set進session中，才可以進行操作。

3、每次發送請求需要使用不同的socket連接。

 

 

下面貼一部分代碼：（代碼有很多疏漏之處，歡迎指正，共同進步）

 

轉載請標明出處。

 

1、獲取連接

BOOL CforceOutLineDlg::ConnectToServer(const CString strServerUrl,SOCKET& socketClient, const unsigned short nPort)
{   
    BOOL bRet = FALSE;  
    WSADATA wsaData;
    WORD wVersion = MAKEWORD(2,2);

    do   
    {  
        if(0 != WSAStartup(wVersion, &wsaData))  
        {  
            break;  
        }  

        if(LOBYTE( wsaData.wVersion ) != 2 || HIBYTE( wsaData.wVersion ) != 2 )  
        {  
            WSACleanup();  
            break;  
        }  

        LPHOSTENT lpHostTent;  
        lpHostTent = gethostbyname(strServerUrl);///根據url獲取ip
        if (NULL == lpHostTent)  
        {
            break;  
        }

        
        if (socketClient == INVALID_SOCKET)  
        {  
            WSACleanup();  
            break;  
        }  

        SOCKADDR_IN socketServer;//服務器
        socketServer.sin_family = AF_INET;  
        socketServer.sin_port = htons(nPort);  
        socketServer.sin_addr = *((LPIN_ADDR)*lpHostTent->h_addr_list);  


        socketClient = socket(AF_INET, SOCK_STREAM, 0);

        if (SOCKET_ERROR == connect(socketClient, (LPSOCKADDR)&socketServer, sizeof(SOCKADDR_IN)))  
        {
            int nErrorCode = WSAGetLastError();  
            closesocket(socketClient);  
            break;
        }  

        bRet = TRUE;  
    } while (FALSE);

    return bRet;
}  

2、接收驗證碼

BOOL CforceOutLineDlg::GetValidateCode(/*SOCKET s,*/CString sessionid)
{
	SOCKET client;
	ConnectToServer("IP",client);//初始化連接

	CString cstrSendData;

	cstrSendData = "GET /RandomCodeAction.action?randomNum=0.1 HTTP/1.1\r\n";
	cstrSendData += "Host:     \r\n";
	cstrSendData += "Connection: keep-alive\r\n";
	cstrSendData += "Accept: image/webp,image/*,*/*;q=0.8\r\n";
	cstrSendData += "User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/49.0.2623.87 Safari/537.36\r\n";
	cstrSendData += "Referer:\r\n";
	cstrSendData += "Accept-Encoding: gzip, deflate, sdch\r\n";
	cstrSendData += "Accept-Language: zh-CN,zh;q=0.8\r\n";
	cstrSendData += "Cookie: JSESSIONID=" + sessionid + "\r\n";
	cstrSendData += "\r\n";


	if (-1 == send(client, cstrSendData.GetBuffer(), cstrSendData.GetLength(), 0))  
	{  
		return FALSE;
	}

	char buff[4096]={0};

	Sleep(1000);//延時1秒，等待圖片流接收完畢

	recv(client, buff, sizeof(buff),0);

	CString temp = buff;

	int nFirst = temp.Find("close",0);

	if(nFirst == -1)
		return FALSE;

	nFirst += 9;//加上close  兩個\r\n  一個 0 的長度

	int picLength = GetPicLength(buff+nFirst);

	ofstream out("aa.png",ios::out|ios::binary);

	out.write(buff+nFirst,picLength);

	out.flush();

	out.close();

	closesocket(client);

	return TRUE;
}



int CforceOutLineDlg::GetPicLength(char* pic)//查找到連續5個 0x00 的位置
{
	int count = 0,i;
	for(i = 0;;i++)
	{
		if(pic[i]==0)
		{
			count++;
			if(count==5)
			{
				break;
			}
		}
		else
		{
			count = 0;
		}
	}
	return i-4;
}

3、URlEncode

CString CforceOutLineDlg::UrlEncode(const CString& szToEncode)
{  
	std::string src = szToEncode;  
	char hex[] = "0123456789ABCDEF";  
	CString dst;  


	for (size_t i = 0; i < src.size(); ++i)  
	{  
		unsigned char cc = src[i];
		if(cc == '\\')
			continue;

		if ( cc >= 'A' && cc <= 'Z'   
			|| cc >='a' && cc <= 'z'  
			|| cc >='0' && cc <= '9'  
			|| cc == '.'  
			|| cc == '_'  
			|| cc == '-'  
			|| cc == '*'
			)  
		{  
			if (cc == ' ')  
			{  
				dst += "+";  
			}  
			else  
				dst += cc;  
		}  
		else  
		{  
			unsigned char c = static_cast<unsigned char>(src[i]);  
			dst += '%';  
			dst += hex[c / 16];  
			dst += hex[c % 16];  
		}  
	}  

	return dst;
}  

　　轉載請標明出處。