| 1 | /****************************************************************************
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| 2 | **
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| 3 | ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
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| 4 | ** All rights reserved.
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| 5 | ** Contact: Nokia Corporation ([email protected])
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| 6 | **
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| 7 | ** This file is part of the documentation of the Qt Toolkit.
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| 8 | **
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| 9 | ** $QT_BEGIN_LICENSE:LGPL$
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| 10 | ** Commercial Usage
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| 11 | ** Licensees holding valid Qt Commercial licenses may use this file in
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| 12 | ** accordance with the Qt Commercial License Agreement provided with the
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| 13 | ** Software or, alternatively, in accordance with the terms contained in
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| 14 | ** a written agreement between you and Nokia.
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| 15 | **
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| 16 | ** GNU Lesser General Public License Usage
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| 17 | ** Alternatively, this file may be used under the terms of the GNU Lesser
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| 18 | ** General Public License version 2.1 as published by the Free Software
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| 23 | **
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| 24 | ** In addition, as a special exception, Nokia gives you certain additional
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| 25 | ** rights. These rights are described in the Nokia Qt LGPL Exception
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| 26 | ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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| 27 | **
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| 28 | ** GNU General Public License Usage
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| 29 | ** Alternatively, this file may be used under the terms of the GNU
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| 30 | ** General Public License version 3.0 as published by the Free Software
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| 31 | ** Foundation and appearing in the file LICENSE.GPL included in the
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| 36 | ** If you have questions regarding the use of this file, please contact
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| 37 | ** Nokia at [email protected].
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| 38 | ** $QT_END_LICENSE$
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| 39 | **
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| 40 | ****************************************************************************/
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| 41 |
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| 42 | /*!
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| 43 | \example network/fortuneclient
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| 44 | \title Fortune Client Example
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| 45 |
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| 46 | The Fortune Client example shows how to create a client for a simple
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| 47 | network service using QTcpSocket. It is intended to be run alongside the
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| 48 | \l{network/fortuneserver}{Fortune Server} example or
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| 49 | the \l{network/threadedfortuneserver}{Threaded Fortune Server} example.
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| 50 |
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| 51 | \image fortuneclient-example.png Screenshot of the Fortune Client example
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| 52 |
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| 53 | This example uses a simple QDataStream-based data transfer protocol to
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| 54 | request a line of text from a fortune server (from the
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| 55 | \l{network/fortuneserver}{Fortune Server} example). The client requests a
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| 56 | fortune by simply connecting to the server. The server then responds with
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| 57 | a 16-bit (quint16) integer containing the length of the fortune text,
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| 58 | followed by a QString.
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| 59 |
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| 60 | QTcpSocket supports two general approaches to network programming:
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| 61 |
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| 62 | \list
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| 63 |
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| 64 | \o \e{The asynchronous (non-blocking) approach.} Operations are scheduled
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| 65 | and performed when control returns to Qt's event loop. When the operation
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| 66 | is finished, QTcpSocket emits a signal. For example,
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| 67 | QTcpSocket::connectToHost() returns immediately, and when the connection
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| 68 | has been established, QTcpSocket emits
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| 69 | \l{QTcpSocket::connected()}{connected()}.
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| 70 |
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| 71 | \o \e{The synchronous (blocking) approach.} In non-GUI and multithreaded
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| 72 | applications, you can call the \c waitFor...() functions (e.g.,
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| 73 | QTcpSocket::waitForConnected()) to suspend the calling thread until the
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| 74 | operation has completed, instead of connecting to signals.
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