QTcpsocket Server and Clinet Problem

[praveen0991kr]

Hi All,
I have created one server and one Client

Client ---send Data-----to-----> Server

Server----Read Data----->But Could Not Reply after Prasing

I have taken reference code of fortune server and client:

Server.cpp------------------------------

 Server::Server(QWidget *parent): QDialog(parent)
 , statusLabel(new QLabel)
 , tcpServer(Q_NULLPTR)
 , networkSession(0)
         , blockSize(0)
         , tcpSocket(new QTcpSocket(this))
 
        {
        QString ipAddress;
        statusLabel->setTextInteractionFlags(Qt::TextBrowserInteraction);

        statusLabel->setText(tr("Opening network session."));

        tcpServer = new QTcpServer(this);
        QHostAddress hostadd("127.0.0.1");

        if (!tcpServer->listen(hostadd,8003)) {
            QMessageBox::critical(this, tr("Fortune Server"),tr("Unable to start the server: %1.")
                              .arg(tcpServer->errorString()));
        close();
         return;
        }
        ipAddress = QHostAddress(QHostAddress::LocalHost).toString();
        statusLabel->setText(tr("The server is running on\n\nIP: %1\nport: %2\n\n Run the Fortune Client example now.")
                         .arg(ipAddress).arg(tcpServer->serverPort()));

        qDebug() <<"IP ADD and PORT: "<< ipAddress << tcpServer->serverPort();

        fortunes << tr("You've been leading a dog's life. Stay off the furniture.")
                 << tr("You've got to think about tomorrow.")
                 << tr("You will be surprised by a loud noise.")
                 << tr("You will feel hungry again in another hour.")
                 << tr("You might have mail.")
                 << tr("You cannot kill time without injuring eternity.")
                 << tr("Computers are not intelligent. They only think they are.");

        QPushButton *quitButton = new QPushButton(tr("Quit"));
        lbl = new QPushButton("lbl");
        quitButton->setAutoDefault(false);

        connect(quitButton, &QAbstractButton::clicked, this, &QWidget::close);
        connect(tcpServer, &QTcpServer::newConnection, this, &Server::sendWelcomeMessage);
        typedef void (QAbstractSocket::*QAbstractSocketErrorSignal)(QAbstractSocket::SocketError);
        connect(tcpSocket, static_cast<QAbstractSocketErrorSignal>(&QAbstractSocket::error),this, &Server::displayError);

       
///I have created One function as follows for handling NewConnection()

           void Server::sendWelcomeMessage()
            {
            typedef QVector<QTcpSocket*> Connections; // <-- Define this at the class level
            Connections connections; // This too
            lbl->setText(QString("%1").arg("Inwelcome"));

            blockSize = 0;
            QDataStream out(&block, QIODevice::WriteOnly);
            out.setVersion(QDataStream::Qt_4_0);

            out << (quint16)0;
            out << fortunes.at(qrand() % fortunes.size());
            out.device()->seek(0);
            out << (quint16)(block.size() - sizeof(quint16));


                if(tcpServer->hasPendingConnections ()) {
                      lbl->setText(QString("%1").arg("hasPen"));
                    QTcpSocket *client = tcpServer->nextPendingConnection();
                    QSignalMapper *signalMapper = new QSignalMapper(this);
                    connect(client, SIGNAL(disconnected()), client, SLOT(deleteLater()));
                    connect(client, SIGNAL(readyRead()), signalMapper, SLOT(map())); // Signal mapper is defined in the class definition and created in the constructor, see QSignalMapper.

                    signalMapper->setMapping(client, client);
                    connect(signalMapper,SIGNAL(mapped(QObject *)),this,SLOT(clientReadyRead(QObject *)));
                    client1=client;
                    client->write(block);
                }
}

        void Server::clientReadyRead(QObject *socket)
        {
       lbl->setText(QString("%1").arg("CReadyRead"));
       QTcpSocket *clientSocket = qobject_cast<QTcpSocket *>(socket);
       int Bytes(clientSocket->bytesAvailable());
       lbl->setText(QString("%1").arg(QString::number(Bytes)));
       QByteArray bufferData = QByteArray::fromRawData(clientSocket->readAll(),Bytes);
       for(int tst=0;tst<bufferData.size();tst++){
       lbl->setText(QString("%1").arg(bufferData[tst]));

       int mycounter = bufferData.indexOf("?R",0);

       bufferData = bufferData.mid(mycounter);
       lbl->setText(QString("%1").arg(bufferData[0]));
       }

       QDataStream out(&bufferData, QIODevice::WriteOnly);
       out.setVersion(QDataStream::Qt_4_0);
       out << bufferData;
       client1->write(block);
       client1->disconnectFromHost();
       delete client1;
        }

Client.cpp--------------Clinet.cpp This set of code able to receive and send data from NewConnection Slot not from ReadyReady Slot to Server ----------------

    void Client::readFortune()
      {

      QDataStream in(tcpSocket);
      in.setVersion(QDataStream::Qt_4_0);
      this->lbl->setText(QString("%1").arg(QString::number(0)));
      QByteArray ba("POST / HTTP/1.1\r\nUser-Agent: Mozilla/Firefox3.6.12\r    \nContent-Type: application/json\r\n\Content-Length: 48\r\nConnection: Keep-Alive\r\nAccept-Encoding: gzip, deflate\r\nAccept-Language: en-IN,*\r\nHost: 127.0.0.1:8003\r\n\r\n""?RegName=NA&RegAdd=NA&EnterData=Status&Value=@@@");

         int bytes = tcpSocket->write(ba,ba.size());
         this->lbl->setText(QString("%1").arg(QString::number(bytes)));
         if (blockSize == 0) {
         if (tcpSocket->bytesAvailable() < (int)sizeof(quint16))
            return;

        in >> blockSize;
         }

        if (tcpSocket->bytesAvailable() < blockSize)
        return;


         QString nextFortune;
         in >> nextFortune;

         if (nextFortune == currentFortune) {
         QTimer::singleShot(0, this, &Client::requestNewFortune);
         return;
         }

         currentFortune = nextFortune;

         statusLabel->setText(currentFortune);
         getFortuneButton->setEnabled(true);
         }

I am sending data from Client and I can able to receive in ReadyRead Slot on ReadyRead Signal Called I have extracted required data but not able to send data from ReadyRead Slot

Data received from Client and NewConnection Slot Called and I am only write data to client from NewConnection but when data received and ReadyRead is called I am not able to send data from there how to send data from readyRead() Slot ---> clientReadyRead(QObject *socket) in Sever.cpp

Thanks and Regards
Praveen

[VRonin]

This is a piece of art

QDataStream out(&bufferData, QIODevice::WriteOnly);
out.setVersion(QDataStream::Qt_4_0);
out << bufferData;

check out page 361 of http://www.bogotobogo.com/cplusplus/files/c-gui-programming-with-qt-4-2ndedition.pdf