- Qt 5.5
- Qt Network
- Fortune Server Example
- server.cpp Example File
- Qt 5.5.1 Reference Documentation

# server.cpp Example File

fortuneserver/server.cpp

    /****************************************************************************
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    ** This file is part of the examples of the Qt Toolkit.
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    #include <QtWidgets>
    #include <QtNetwork>

    #include <stdlib.h>

    #include "server.h"

    Server::Server(QWidget *parent)
    :   QDialog(parent), tcpServer(0), networkSession(0)
    {
        statusLabel = new QLabel;
        quitButton = new QPushButton(tr("Quit"));
        quitButton->setAutoDefault(false);

        QNetworkConfigurationManager manager;
        if (manager.capabilities() & QNetworkConfigurationManager::NetworkSessionRequired) {
            // Get saved network configuration
            QSettings settings(QSettings::UserScope, QLatin1String("QtProject"));
            settings.beginGroup(QLatin1String("QtNetwork"));
            const QString id = settings.value(QLatin1String("DefaultNetworkConfiguration")).toString();
            settings.endGroup();

            // If the saved network configuration is not currently discovered use the system default
            QNetworkConfiguration config = manager.configurationFromIdentifier(id);
            if ((config.state() & QNetworkConfiguration::Discovered) !=
                QNetworkConfiguration::Discovered) {
                config = manager.defaultConfiguration();
            }

            networkSession = new QNetworkSession(config, this);
            connect(networkSession, SIGNAL(opened()), this, SLOT(sessionOpened()));

            statusLabel->setText(tr("Opening network session."));
            networkSession->open();
        } else {
            sessionOpened();
        }

            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.");

            connect(quitButton, SIGNAL(clicked()), this, SLOT(close()));
            connect(tcpServer, SIGNAL(newConnection()), this, SLOT(sendFortune()));

            QHBoxLayout *buttonLayout = new QHBoxLayout;
            buttonLayout->addStretch(1);
            buttonLayout->addWidget(quitButton);
            buttonLayout->addStretch(1);

            QVBoxLayout *mainLayout = new QVBoxLayout;
            mainLayout->addWidget(statusLabel);
            mainLayout->addLayout(buttonLayout);
            setLayout(mainLayout);

            setWindowTitle(tr("Fortune Server"));
    }

    void Server::sessionOpened()
    {
        // Save the used configuration
        if (networkSession) {
            QNetworkConfiguration config = networkSession->configuration();
            QString id;
            if (config.type() == QNetworkConfiguration::UserChoice)
                id = networkSession->sessionProperty(QLatin1String("UserChoiceConfiguration")).toString();
            else
                id = config.identifier();

            QSettings settings(QSettings::UserScope, QLatin1String("QtProject"));
            settings.beginGroup(QLatin1String("QtNetwork"));
            settings.setValue(QLatin1String("DefaultNetworkConfiguration"), id);
            settings.endGroup();
        }

        tcpServer = new QTcpServer(this);
        if (!tcpServer->listen()) {
            QMessageBox::critical(this, tr("Fortune Server"),
                                  tr("Unable to start the server: %1.")
                                  .arg(tcpServer->errorString()));
            close();
            return;
        }
        QString ipAddress;
        QList<QHostAddress> ipAddressesList = QNetworkInterface::allAddresses();
        // use the first non-localhost IPv4 address
        for (int i = 0; i < ipAddressesList.size(); ++i) {
            if (ipAddressesList.at(i) != QHostAddress::LocalHost &&
                ipAddressesList.at(i).toIPv4Address()) {
                ipAddress = ipAddressesList.at(i).toString();
                break;
            }
        }
        // if we did not find one, use IPv4 localhost
        if (ipAddress.isEmpty())
            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()));
    }

    void Server::sendFortune()
    {
        QByteArray block;
        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));

        QTcpSocket *clientConnection = tcpServer->nextPendingConnection();
        connect(clientConnection, SIGNAL(disconnected()),
                clientConnection, SLOT(deleteLater()));

        clientConnection->write(block);
        clientConnection->disconnectFromHost();
    }