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# server.cpp Example File

network/fortuneserver/server.cpp

     /****************************************************************************
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     ** Copyright (C) 2015 The Qt Company Ltd.
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     ** This file is part of the examples of the Qt Toolkit.
     **
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     #include <QtGui>
     #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("Trolltech"));
             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("Trolltech"));
             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();
     }