publish − Publication example
#include
<stdio.h>
#include <stdlib.h>
#include <string.h>
#include "MQTTAsync.h"
#if
!defined(_WIN32)
#include <unistd.h>
#else
#include <windows.h>
#endif
#if
defined(_WRS_KERNEL)
#include <OsWrapper.h>
#endif
#define ADDRESS
"tcp://mqtt.eclipseprojects.io:1883"
#define CLIENTID "ExampleClientPub"
#define TOPIC "MQTT Examples"
#define PAYLOAD "Hello World!"
#define QOS 1
#define TIMEOUT 10000L
int finished = 0;
void
connlost(void *context, char *cause)
{
MQTTAsync client = (MQTTAsync)context;
MQTTAsync_connectOptions conn_opts =
MQTTAsync_connectOptions_initializer;
int rc;
printf("1onnection
lost0);
printf(" cause: %s0, cause);
printf("Reconnecting0);
conn_opts.keepAliveInterval = 20;
conn_opts.cleansession = 1;
if ((rc = MQTTAsync_connect(client, &conn_opts)) !=
MQTTASYNC_SUCCESS)
{
printf("Failed to start connect, return code %d0, rc);
finished = 1;
}
}
void
onDisconnectFailure(void* context, MQTTAsync_failureData*
response)
{
printf("Disconnect failed0);
finished = 1;
}
void
onDisconnect(void* context, MQTTAsync_successData* response)
{
printf("Successful disconnection0);
finished = 1;
}
void
onSendFailure(void* context, MQTTAsync_failureData*
response)
{
MQTTAsync client = (MQTTAsync)context;
MQTTAsync_disconnectOptions opts =
MQTTAsync_disconnectOptions_initializer;
int rc;
printf("Message
send failed token %d error code %d0, response->token,
response->code);
opts.onSuccess = onDisconnect;
opts.onFailure = onDisconnectFailure;
opts.context = client;
if ((rc = MQTTAsync_disconnect(client, &opts)) !=
MQTTASYNC_SUCCESS)
{
printf("Failed to start disconnect, return code %d0,
rc);
exit(EXIT_FAILURE);
}
}
void
onSend(void* context, MQTTAsync_successData* response)
{
MQTTAsync client = (MQTTAsync)context;
MQTTAsync_disconnectOptions opts =
MQTTAsync_disconnectOptions_initializer;
int rc;
printf("Message
with token value %d delivery confirmed0,
response->token);
opts.onSuccess = onDisconnect;
opts.onFailure = onDisconnectFailure;
opts.context = client;
if ((rc = MQTTAsync_disconnect(client, &opts)) !=
MQTTASYNC_SUCCESS)
{
printf("Failed to start disconnect, return code %d0,
rc);
exit(EXIT_FAILURE);
}
}
void
onConnectFailure(void* context, MQTTAsync_failureData*
response)
{
printf("Connect failed, rc %d0, response ?
response->code : 0);
finished = 1;
}
void
onConnect(void* context, MQTTAsync_successData* response)
{
MQTTAsync client = (MQTTAsync)context;
MQTTAsync_responseOptions opts =
MQTTAsync_responseOptions_initializer;
MQTTAsync_message pubmsg = MQTTAsync_message_initializer;
int rc;
printf("Successful
connection0);
opts.onSuccess = onSend;
opts.onFailure = onSendFailure;
opts.context = client;
pubmsg.payload = PAYLOAD;
pubmsg.payloadlen = (int)strlen(PAYLOAD);
pubmsg.qos = QOS;
pubmsg.retained = 0;
if ((rc = MQTTAsync_sendMessage(client, TOPIC, &pubmsg,
&opts)) != MQTTASYNC_SUCCESS)
{
printf("Failed to start sendMessage, return code %d0,
rc);
exit(EXIT_FAILURE);
}
}
int
messageArrived(void* context, char* topicName, int topicLen,
MQTTAsync_message* m)
{
// not expecting any messages
return 1;
}
int main(int
argc, char* argv[])
{
MQTTAsync client;
MQTTAsync_connectOptions conn_opts =
MQTTAsync_connectOptions_initializer;
int rc;
if ((rc =
MQTTAsync_create(&client, ADDRESS, CLIENTID,
MQTTCLIENT_PERSISTENCE_NONE, NULL)) != MQTTASYNC_SUCCESS)
{
printf("Failed to create client object, return code
%d0, rc);
exit(EXIT_FAILURE);
}
if ((rc =
MQTTAsync_setCallbacks(client, NULL, connlost,
messageArrived, NULL)) != MQTTASYNC_SUCCESS)
{
printf("Failed to set callback, return code %d0, rc);
exit(EXIT_FAILURE);
}
conn_opts.keepAliveInterval
= 20;
conn_opts.cleansession = 1;
conn_opts.onSuccess = onConnect;
conn_opts.onFailure = onConnectFailure;
conn_opts.context = client;
if ((rc = MQTTAsync_connect(client, &conn_opts)) !=
MQTTASYNC_SUCCESS)
{
printf("Failed to start connect, return code %d0, rc);
exit(EXIT_FAILURE);
}
printf("Waiting
for publication of %s0
"on topic %s for client with ClientID: %s0,
PAYLOAD, TOPIC, CLIENTID);
while (!finished)
#if defined(_WIN32)
Sleep(100);
#else
usleep(10000L);
#endif
MQTTAsync_destroy(&client);
return rc;
}