mirror of
https://github.com/eclipse/paho.mqtt.cpp.git
synced 2025-05-09 11:21:24 +08:00
381caad141
- Added property typeid, type name, and cleaned up constructor. - Exception checks if return code is reason code. - Added 'server_property_v5' example app.
118 lines
4.0 KiB
C++
118 lines
4.0 KiB
C++
// server_props_v5.cpp
|
|
//
|
|
// This is a Paho MQTT C++ client, sample application.
|
|
//
|
|
// This application is an MQTT client using the C++ asynchronous interface
|
|
// which shows how to check the server cofiguration for an MQTT v5
|
|
// connection.
|
|
//
|
|
// With an MQTT v5 connection, the server specify can some features that it
|
|
// doesn't supports, or limits in some way. It does this by adding v5
|
|
// properties to the CONNACK packet it sends back to the client in a connect
|
|
// transaction. The C++ application can retrieve these from the connect
|
|
// token via the `connect_response` object.
|
|
//
|
|
// It also shows short-lived persistent sessions. The client asks the server
|
|
// to just keep the session for 10sec. If you re-run the application in less
|
|
// than 10sec, it should report that the session exists. Any longer, and the
|
|
// session will be gone.
|
|
//
|
|
// Note that 10sec is probably *way too short* a time for real-world
|
|
// applications. This is just for demonstrating/testing the session expiry
|
|
// interval.
|
|
//
|
|
// The sample demonstrates:
|
|
// - Connecting to an MQTT v5 server/broker.
|
|
// - Specifying a short-lived (10sec) persistent session.
|
|
// - Retrieving the v5 properties from the connect response (i.e. CONNACK
|
|
// packet)
|
|
// - Iterating through v5 properties.
|
|
// - Displaying server properties to the user.
|
|
//
|
|
|
|
/*******************************************************************************
|
|
* Copyright (c) 2013-2024 Frank Pagliughi <fpagliughi@mindspring.com>
|
|
*
|
|
* All rights reserved. This program and the accompanying materials
|
|
* are made available under the terms of the Eclipse Public License v2.0
|
|
* and Eclipse Distribution License v1.0 which accompany this distribution.
|
|
*
|
|
* The Eclipse Public License is available at
|
|
* http://www.eclipse.org/legal/epl-v20.html
|
|
* and the Eclipse Distribution License is available at
|
|
* http://www.eclipse.org/org/documents/edl-v10.php.
|
|
*
|
|
* Contributors:
|
|
* Frank Pagliughi - initial implementation and documentation
|
|
*******************************************************************************/
|
|
|
|
#include <cctype>
|
|
#include <chrono>
|
|
#include <cstdlib>
|
|
#include <cstring>
|
|
#include <iostream>
|
|
#include <string>
|
|
#include <thread>
|
|
|
|
#include "mqtt/async_client.h"
|
|
|
|
using namespace std;
|
|
|
|
const string DFLT_SERVER_URI{"mqtt://localhost:1883"};
|
|
const string CLIENT_ID{"server_props_v5"};
|
|
|
|
/////////////////////////////////////////////////////////////////////////////
|
|
|
|
int main(int argc, char* argv[])
|
|
{
|
|
auto serverURI = (argc > 1) ? string{argv[1]} : DFLT_SERVER_URI;
|
|
|
|
mqtt::async_client cli(serverURI, CLIENT_ID);
|
|
auto connOpts = mqtt::connect_options_builder::v5()
|
|
.clean_start(false)
|
|
.properties({{mqtt::property::SESSION_EXPIRY_INTERVAL, 10}})
|
|
.finalize();
|
|
|
|
try {
|
|
// Connect to the server
|
|
|
|
cout << "Connecting to the MQTT server at '" << serverURI << "'..." << flush;
|
|
auto tok = cli.connect(connOpts);
|
|
|
|
// Getting the connect response will block waiting for the
|
|
// connection to complete.
|
|
auto rsp = tok->get_connect_response();
|
|
cout << "OK" << endl;
|
|
|
|
// Make sure we were granted a v5 connection.
|
|
if (rsp.get_mqtt_version() < MQTTVERSION_5) {
|
|
cout << "Did not get an MQTT v5 connection." << endl;
|
|
exit(1);
|
|
}
|
|
|
|
// Does the server have a session for us?
|
|
cout << "\nThe session is " << (rsp.is_session_present() ? "" : "not ")
|
|
<< "present on the server." << endl;
|
|
|
|
// Show the v5 properties from the CONNACK, if any
|
|
cout << "\nConnection Properties:" << endl;
|
|
if (rsp.get_properties().empty()) {
|
|
cout << " <none>" << endl;
|
|
}
|
|
else {
|
|
for (const auto& prop : rsp.get_properties()) {
|
|
cout << " " << prop << endl;
|
|
}
|
|
}
|
|
|
|
// OK, we're done.
|
|
cli.disconnect()->wait();
|
|
}
|
|
catch (const mqtt::exception& exc) {
|
|
cerr << "\n " << exc << endl;
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|