Socket Prog

[Vivek1982]

Dear All,

I have developed a SERVER_CLIENT Application, Where Server will receives data from client and present it on the Server Application. I have done with the 1-server and 1-client. If i want to increase the Client Nos. I'm not able to do it.. When same Client application in compiled second time as second client. The data at server end is not processed or to be clear. Data was not sent from Secone client only. How this can be addressed,
1.either we need to create mulitple sockets.. how this can be done having one-Serverapplication.
2. or Can we create a Server Application where it can accept mutilple "ports" (e.g server->listen(QHostAddress::Any,1234, server->listen(QHostAddress::Any,1235)) connections ? in the server application while checking for Newconnections.

[toufic.dbouk]

One approach you could try is every time you get an incoming connection from the server you set a socket and the streams for that user, ( you can make a class user to handle all this ).
So now when a client connects an instance of the class will be created specifically to that user handling his requests.
You will still have one Server socket to listen and you create a client-socket for every user.
That's a general approach. You can find several other ways to solve the issue.

Good Luck.

[anda_skoa]

1.either we need to create mulitple sockets.. how this can be done having one-Serverapplication.

This is done automatically. Each incoming connection gets its own QTcpSocket instance.

2. or Can we create a Server Application where it can accept mutilple "ports" (e.g server->listen(QHostAddress::Any,1234, server->listen(QHostAddress::Any,1235)) connections ? in the server application while checking for Newconnections.

No need for multiple listening ports. All connections to a QTcpServer result in new QTcpSocket objects being created, one for each incoming connection/client.

Cheers,
_

[Vivek1982]

Thanks for all your replies. I will give an attempt to create a multiple Sockets for adding new clients into my server application. I hope I may example(Qt inbuilt) for this to unsderstand, how coding/ creating multiple socket can be done.

[anda_skoa]

Just to be sure you understood this correctly: you don't need to create multiple sockets, they are created for you. This is what the QTcpServer ultimately does.

Cheers,
_

[Vivek1982]

Hi. I have tried upto my level how to create a Server to handle many clients, but my non of the debug msgs are working. Im presenting my simple Server client code.plz support me.

Teamstatus.h

class TeamStatus : public QMainWindow {
    Q_OBJECT
public:
    TeamStatus(QWidget *parent = 0);
    ~TeamStatus();
    void listen();
     void socketdisc();
protected:
    void changeEvent(QEvent *e);
void incomingConnection(int socketfd);
 
private:
    Ui::TeamStatus *ui1;
QTcpServer *server;
    QSet <QTcpSocket*>  sockets;
public slots:
 void read_socket();

class TeamStatus : public QMainWindow {
    Q_OBJECT
public:
    TeamStatus(QWidget *parent = 0);
    ~TeamStatus();
    void listen();
     void socketdisc();
protected:
    void changeEvent(QEvent *e);
void incomingConnection(int socketfd);

private:
    Ui::TeamStatus *ui1;
QTcpServer *server;
    QSet <QTcpSocket*>  sockets;
public slots:
 void read_socket();

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Teamstatus.cpp

TeamStatus::TeamStatus(QWidget *parent) :
    QMainWindow(parent),
    ui1(new Ui::TeamStatus)
{
    ui1->setupUi(this);
server=new QTcpServer(this);
TeamStatus::~TeamStatus()
{
 
    delete ui1;
}
void TeamStatus::listen()
 
 
{
    QHostAddress hAddr;
    hAddr.setAddress("192.168.64.55");
 
        server->listen(QHostAddress::Any,1234);
       qDebug("Listening to new connection");
           qDebug("listening for new socket")
      }
 
void TeamStatus::incomingConnection(int socketfd)
{{
 
        socket=server->nextPendingConnection();
            if((socket->state()==QTcpSocket::ConnectedState))
        {
                 QTcpSocket *socket = new QTcpSocket;
                socket->setSocketDescriptor(socketfd);
 
                qDebug("new connection1 established");
 
        }
        {
}
         qDebug("new connection1 established");
 
                  }
 
        read_socket();
 
 
    }
 
 
 
void TeamStatus::read_socket()
{
    QTcpSocket *socket=new QTcpSocket;
    socket=(QTcpSocket*) sender();
 
    qDebug("after readingy);
    QByteArray buffer= socket->readLine();
... check for the buffer, do something
 
void TeamStatus::write_socket()
{
"How to write the data or send packet to single client or for all clients"
}

TeamStatus::TeamStatus(QWidget *parent) :
    QMainWindow(parent),
    ui1(new Ui::TeamStatus)
{
    ui1->setupUi(this);
server=new QTcpServer(this);
TeamStatus::~TeamStatus()
{

    delete ui1;
}
void TeamStatus::listen()


{
    QHostAddress hAddr;
    hAddr.setAddress("192.168.64.55");

        server->listen(QHostAddress::Any,1234);
       qDebug("Listening to new connection");
           qDebug("listening for new socket")
      }

void TeamStatus::incomingConnection(int socketfd)
{{

        socket=server->nextPendingConnection();
            if((socket->state()==QTcpSocket::ConnectedState))
        {
                 QTcpSocket *socket = new QTcpSocket;
                socket->setSocketDescriptor(socketfd);

                qDebug("new connection1 established");

        }
        {
}
         qDebug("new connection1 established");

                  }

        read_socket();
      

    }



void TeamStatus::read_socket()
{
    QTcpSocket *socket=new QTcpSocket;
    socket=(QTcpSocket*) sender();

    qDebug("after readingy);
    QByteArray buffer= socket->readLine();
... check for the buffer, do something

void TeamStatus::write_socket()
{
"How to write the data or send packet to single client or for all clients"
}

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Client.h

class QTcpSocket;
 
namespace Ui {
    class TCPClient;
}
 
class TCPClient : public QWidget {
    Q_OBJECT
public:
    TCPClient(QWidget *parent = 0);
    ~TCPClient();
 
protected:
    void changeEvent(QEvent *e);
 
private:
    Ui::TCPClient *ui;
    QLineEdit *le,*le1;
    QTextEdit *te,*te1;
    QPushButton  *pb_connect, *pb_disconnect;
    QPushButton *pb_send,*pb_send1;
    QTcpSocket *socket;
    QString CHAT;
 
private slots:
            void connecttoserver();
            void on_connected();
            void write();
            void write1();
            void DisconnectServer();
 
        };
 
#endif // TCPCLIENT_H

class QTcpSocket;

namespace Ui {
    class TCPClient;
}

class TCPClient : public QWidget {
    Q_OBJECT
public:
    TCPClient(QWidget *parent = 0);
    ~TCPClient();

protected:
    void changeEvent(QEvent *e);

private:
    Ui::TCPClient *ui;
    QLineEdit *le,*le1;
    QTextEdit *te,*te1;
    QPushButton  *pb_connect, *pb_disconnect;
    QPushButton *pb_send,*pb_send1;
    QTcpSocket *socket;
    QString CHAT;

private slots:
            void connecttoserver();
            void on_connected();
            void write();
            void write1();
            void DisconnectServer();
           
        };

#endif // TCPCLIENT_H

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Client.cpp

TCPClient::TCPClient(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::TCPClient)
{
    ui->setupUi(this);
 
    le= new QLineEdit;
    le=ui->lineEdit;
    le->setDisabled(true);
 
    le1=new QLineEdit;
    le1=ui->lineEdit_2;
    le1->setDisabled(true);
 
    te=new QTextEdit;
    te=ui->textEdit;
    te->setDisabled(true);
 
    te1=new QTextEdit;
    te1=ui->textEdit_2;
    te1->setDisabled(true);
 
    pb_connect=new QPushButton;
    pb_connect=ui->pushButton;
    pb_connect->setText("CONNECT");
    pb_connect->setEnabled(true);
 
    pb_send=new QPushButton;
    pb_send=ui->pushButton_2;
    pb_send->setText("Send");
    pb_send->setEnabled(false);
 
    pb_send1=new QPushButton;
    pb_send1=ui->pushButton_3;
    pb_send1->setText("SEND");
    pb_send1->setEnabled(false);
 
    pb_disconnect=new QPushButton;
    pb_disconnect=ui->pushButton_4;
    pb_disconnect->setEnabled(false);
    pb_disconnect->setText("DISCONNECT");
 
 
 
    socket=new QTcpSocket(this);
 
    connect(pb_connect,SIGNAL(clicked()),this,SLOT(connecttoserver()));
    connect(pb_send,SIGNAL(clicked()),this,SLOT(write()));
    connect(pb_send1,SIGNAL(clicked()),this,SLOT(write1()));
    connect(pb_disconnect,SIGNAL(clicked()),this,SLOT(DisconnectServer()));
    connect(socket,SIGNAL(connected()),this,SLOT(on_connected()));
    connect(socket,SIGNAL(readyRead()),this,SLOT(read1()));
 
}
 
TCPClient::~TCPClient()
{
    delete ui;
}
 
void TCPClient::changeEvent(QEvent *e)
{
    QWidget::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        ui->retranslateUi(this);
        break;
    default:
        break;
    }
}
 
void TCPClient::connecttoserver()
{
    QHostAddress hAddr;
     hAddr.setAddress("192.168.64.55");
    socket->connectToHost(hAddr,1234);
 
}
 
void TCPClient::on_connected()
{
    pb_connect->setEnabled(false);
    pb_send->setEnabled(true);
    pb_send1->setEnabled(true);
    qDebug("Connection established");
    pb_disconnect->setEnabled(true);
    le->setEnabled(true);
    le1->setEnabled(true);
    te->setEnabled(true);
    te1->setEnabled(true);
}
 
void TCPClient::write()
{
      QString Data="",Data1=this->le->text();
    CHAT="1";
    Data.append(CHAT);
    Data.append(Data1);
    socket->write(Data.toUtf8().constData());
    qDebug("Client Sent 1 to Server");
 
   }
void TCPClient::write1()
{
       QString Data="",Data1=this->le->text();
    CHAT="2";
    Data.append(CHAT);
    Data.append(Data1);
    socket->write(Data.toUtf8().constData());
    qDebug("Client Sent 2 to server");
 
   // socket->flush();
 
}

TCPClient::TCPClient(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::TCPClient)
{
    ui->setupUi(this);

    le= new QLineEdit;
    le=ui->lineEdit;
    le->setDisabled(true);

    le1=new QLineEdit;
    le1=ui->lineEdit_2;
    le1->setDisabled(true);

    te=new QTextEdit;
    te=ui->textEdit;
    te->setDisabled(true);

    te1=new QTextEdit;
    te1=ui->textEdit_2;
    te1->setDisabled(true);

    pb_connect=new QPushButton;
    pb_connect=ui->pushButton;
    pb_connect->setText("CONNECT");
    pb_connect->setEnabled(true);

    pb_send=new QPushButton;
    pb_send=ui->pushButton_2;
    pb_send->setText("Send");
    pb_send->setEnabled(false);

    pb_send1=new QPushButton;
    pb_send1=ui->pushButton_3;
    pb_send1->setText("SEND");
    pb_send1->setEnabled(false);

    pb_disconnect=new QPushButton;
    pb_disconnect=ui->pushButton_4;
    pb_disconnect->setEnabled(false);
    pb_disconnect->setText("DISCONNECT");



    socket=new QTcpSocket(this);

    connect(pb_connect,SIGNAL(clicked()),this,SLOT(connecttoserver()));
    connect(pb_send,SIGNAL(clicked()),this,SLOT(write()));
    connect(pb_send1,SIGNAL(clicked()),this,SLOT(write1()));
    connect(pb_disconnect,SIGNAL(clicked()),this,SLOT(DisconnectServer()));
    connect(socket,SIGNAL(connected()),this,SLOT(on_connected()));
    connect(socket,SIGNAL(readyRead()),this,SLOT(read1()));

}

TCPClient::~TCPClient()
{
    delete ui;
}

void TCPClient::changeEvent(QEvent *e)
{
    QWidget::changeEvent(e);
    switch (e->type()) {
    case QEvent::LanguageChange:
        ui->retranslateUi(this);
        break;
    default:
        break;
    }
}

void TCPClient::connecttoserver()
{
    QHostAddress hAddr;
     hAddr.setAddress("192.168.64.55");
    socket->connectToHost(hAddr,1234);

}

void TCPClient::on_connected()
{
    pb_connect->setEnabled(false);
    pb_send->setEnabled(true);
    pb_send1->setEnabled(true);
    qDebug("Connection established");
    pb_disconnect->setEnabled(true);
    le->setEnabled(true);
    le1->setEnabled(true);
    te->setEnabled(true);
    te1->setEnabled(true);
}

void TCPClient::write()
{
      QString Data="",Data1=this->le->text();
    CHAT="1";
    Data.append(CHAT);
    Data.append(Data1);
    socket->write(Data.toUtf8().constData());
    qDebug("Client Sent 1 to Server");

   }
void TCPClient::write1()
{
       QString Data="",Data1=this->le->text();
    CHAT="2";
    Data.append(CHAT);
    Data.append(Data1);
    socket->write(Data.toUtf8().constData());
    qDebug("Client Sent 2 to server");

   // socket->flush();

}

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[toufic.dbouk]

Where are you using your listen() method ?
Check if isListening returns true.
And check if the newConnection signal is fired when a client connects , to see if you are actually connecting to your server.
Its not easy to read a code from iphone lol my post might be useless.


Good Luck.

[Vivek1982]

Im using Listen() in one of the child window called Team Status. While compiling Im getting Debug msgs of Listen function. Im not gettin debug msg of New client or Connection accepted msg on the Application output window. earlier When i created one server and one client it works fine. when initialise for two or more clients in the server by

void TeamStatus::incomingConnection(int socketfd)  // Public slot in the teamstatus.H file
{{
        QTcpSocket *socket = new QTcpSocket;
 
        socket=server->nextPendingConnection();
            if((socket->state()==QTcpSocket::ConnectedState))
        {
                socket->setSocketDescriptor(socketfd);
 
                qDebug("new connection1 established");
 
        }

void TeamStatus::incomingConnection(int socketfd)  // Public slot in the teamstatus.H file
{{
        QTcpSocket *socket = new QTcpSocket;

        socket=server->nextPendingConnection();
            if((socket->state()==QTcpSocket::ConnectedState))
        {
                socket->setSocketDescriptor(socketfd);

                qDebug("new connection1 established");

        }

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client

connect(pb_connect,SIGNAL(clicked()),this,SLOT(connecttoserver()));
connect(socket,SIGNAL(connected()),this,SLOT(on_connected()));
void TCPClient::connecttoserver()
{
    QHostAddress hAddr;
     hAddr.setAddress("192.168.64.55");
    socket->connectToHost(hAddr,1234);
 
void TCPClient::on_connected(int descriptor) //public slot of client.h
 
{    
    socket=new QTcpSocket(this);
    socket->setSocketDescriptor(descriptor);
 
 
    connect(pb_send,SIGNAL(clicked()),this,SLOT(write()));
    connect(pb_send1,SIGNAL(clicked()),this,SLOT(write1()));
    connect(pb_disconnect,SIGNAL(clicked()),this,SLOT(DisconnectServer()));
 
    connect(socket,SIGNAL(readyRead()),this,SLOT(read1()));
}
 
void TCPClient::write()
{
      QString Data="",Data1=this->le->text();
    CHAT="1";
    Data.append(CHAT);
    Data.append(Data1);
    socket->write(Data.toUtf8().constData());
    qDebug("Client Sent 1 to Server");
 
}
}

connect(pb_connect,SIGNAL(clicked()),this,SLOT(connecttoserver()));
connect(socket,SIGNAL(connected()),this,SLOT(on_connected()));
void TCPClient::connecttoserver()
{
    QHostAddress hAddr;
     hAddr.setAddress("192.168.64.55");
    socket->connectToHost(hAddr,1234);

void TCPClient::on_connected(int descriptor) //public slot of client.h

{    
    socket=new QTcpSocket(this);
    socket->setSocketDescriptor(descriptor);


    connect(pb_send,SIGNAL(clicked()),this,SLOT(write()));
    connect(pb_send1,SIGNAL(clicked()),this,SLOT(write1()));
    connect(pb_disconnect,SIGNAL(clicked()),this,SLOT(DisconnectServer()));

    connect(socket,SIGNAL(readyRead()),this,SLOT(read1()));
}

void TCPClient::write()
{
      QString Data="",Data1=this->le->text();
    CHAT="1";
    Data.append(CHAT);
    Data.append(Data1);
    socket->write(Data.toUtf8().constData());
    qDebug("Client Sent 1 to Server");

}
}

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If can't later also u can look at the code then reply..
Thanks

[toufic.dbouk]

Is the newConnection signal getting fired ?
Connect it to a slot where you accept the connection.

[anda_skoa]

Connect it to a slot where you accept the connection.

Exactly.

You can't just create a QTcpServer object and expect that it magically knows how to invoke the function in which you call nextPendingConnection().

Programming can look like magic but it isn't

Cheers,
_

[stampede]

Btw. you have a memory leak here:

QTcpSocket *socket = new QTcpSocket; // this object will never be deleted
socket=server->nextPendingConnection();// because you overwrite the only pointer to it here

QTcpSocket *socket = new QTcpSocket; // this object will never be deleted
socket=server->nextPendingConnection();// because you overwrite the only pointer to it here

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[Vivek1982]

ya.. I have given a condition If already socket is accepted/connected. process the debug like new connection established

socket=server->nextPendingConnection();
        if((socket->state()==QTcpSocket::ConnectedState))

socket=server->nextPendingConnection();
        if((socket->state()==QTcpSocket::ConnectedState))

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I feel somewhere I'm going wrong when in creating a socket descriptor while assigning for connecting with many clients.
or using QSet in teamstatus.h for creating more sockets.

[anda_skoa]

There is no need to create a socket descriptor, QTcpServer::nextPendingConnection() creates a fully constructed QTcpSocket object.

Cheers,
_