GO语言mqtt使用(例子)
<h1 id="go语言使用mqtt">GO语言使用mqtt</h1><pre><code>"github.com/eclipse/paho.mqtt.golang"
//mqtt
"github.com/sirupsen/logrus"
//日志
</code></pre>
<pre><code>package mqtt
import (
"crypto/tls"
"encoding/json"
"errors"
"os"
"os/signal"
"time"
"fmt"
MQTT "github.com/eclipse/paho.mqtt.golang"
log "github.com/sirupsen/logrus"
)
var MqttAgent *Agent
//var AgentMqtt *Agent
var MQTTconfig *config.Config
const (
MQTT_QOS=1
MQTTBroker="tcp://xxx.xxx.xxx.xxx:1883"
MQTTClientId="00000001"
)
// Agent runs an mqtt client
type Agent struct {
client MQTT.Client
}
type subscription struct {
topic string
handler MQTT.MessageHandler
}
// NewAgent creates an agent
func NewAgent() ( *Agent) {
a:=new(Agent)
//opts:= MQTT.NewClientOptions().AddBroker(MQTTconfig.MQTTBroker).SetClientID(MQTTconfig.MQTTClientId)
opts:= MQTT.NewClientOptions().AddBroker(MQTTBroker).SetClientID(MQTTClientId)
//opts.SetUsername(MQTTconfig.MQTTUser)
//opts.SetPassword(MQTTconfig.MQTTPasswd)
opts.SetKeepAlive(5 * time.Second)
opts.SetPingTimeout(5 * time.Second)
opts.SetTLSConfig(&tls.Config{
ClientAuth: tls.NoClientCert,
ClientCAs: nil,
InsecureSkipVerify: true,
})
opts.OnConnectionLost = func(c MQTT.Client, err error) {
log.WithField("error", err).Info("Lost connection")
}
a.client= MQTT.NewClient(opts)
a.Connect()
// mqtt.DEBUG = log.New(os.Stdout, "", 0)
// mqtt.ERROR = log.New(os.Stdout, "", 0)
return a
}
func (a *Agent)RegisterMqttHandler(topic string,handler infra.HandlerFunc){
if token := a.client.Subscribe(topic,MQTT_QOS,
func (c MQTT.Client,msg MQTT.Message){
var msgmqtt infra.Entity
var respentity *infra.RespEntity
var ic infra.IComponent
var msgdate infra.Message
//unmarshal the bgp json, execute action and return status
for true {
LogOutResp(topic,msg.Payload())
if err := json.Unmarshal(msg.Payload(), &msgmqtt); err != nil {
log.Error("RegisterMqttHandler Unmarshal fail")
break
}
//Syslog.LogOutObj(msg.Topic(), msgBgp, Syslog.RESP_OK)
msgdate.Entity=&msgmqtt
respentity=handler(ic,topic,&msgdate)
break
}
if respentity!=nil{
//Publish resp to server
resp_topic :=topic+"/resp"
a.SendMqttResp(resp_topic,respentity)
}
}); token.Wait() && token.Error() != nil {
log.WithField("error", token.Error()).Error("Can't subscribe")
os.Exit(1)
}
}
// Connect opens a new connection
func (a *Agent) Connect() (err error) {
token := a.client.Connect()
if token.WaitTimeout(2*time.Second) == false {
return errors.New("Open timeout")
}
if token.Error() != nil {
return token.Error()
}
go func() {
done := make(chan os.Signal)
signal.Notify(done, os.Interrupt)
<-done
log.Info("Shutting down agent")
a.Close()
}()
return
}
// Close agent
func (a *Agent) Close() {
a.client.Disconnect(250)
}
func (a *Agent)SendMqttResp(topic string,msg *infra.RespEntity) {
msgResp := &infra.RespEntity{
Rid: msg.Rid,
Timestamp: uint64(time.Now().Unix()),
Object: msg.Object,
Action: msg.Action,
Code: msg.Code,
Data: msg.Data,
}
payload, err := json.Marshal(msgResp)
log.Info(topic)
log.Info(payload)
if err != nil {
log.WithFields(log.Fields{
"topic": topic,
"rid": msg.Rid,
"obj": msg.Object,
"act": msg.Action,
"code":msg.Code,
"date":msg.Data,}).Info("SendMqttResp: Marshal failed")
return
}
a.Publish(topic, true, string(payload))
}
// Publish things
func (a *Agent) Publish(topic string, retain bool, payload string) (err error) {
token := a.client.Publish(topic, MQTT_QOS, retain, payload)
if token.WaitTimeout(2*time.Second) == false {
return errors.New("Publish timout")
}
if token.Error() != nil {
return token.Error()
}
return nil
}
func LogOutResp(topic string, msg []byte) {
msg_resp := "Response"
msg_val := fmt.Sprintf("Topic=%s Payload=%s", topic, msg)
log.WithField(msg_resp, msg_val).Info(topic)
}
</code></pre>
<pre><code>/*
* Copyright (c) 2013 IBM Corp.
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Seth Hoenig
* Allan Stockdill-Mander
* Mike Robertson
*/
/*----------------------------------------------------------------------
This sample is designed to demonstrate the ability to set individual
callbacks on a per-subscription basis. There are three handlers in use:
brokerLoadHandler - $SYS/broker/load/#
brokerConnectionHandler -$SYS/broker/connection/#
brokerClientHandler - $SYS/broker/clients/#
The client will receive 100 messages total from those subscriptions,
and then print the total number of messages received from each.
It may take a few moments for the sample to complete running, as it
must wait for messages to be published.
-----------------------------------------------------------------------*/
package main
import (
"fmt"
"os"
MQTT "github.com/eclipse/paho.mqtt.golang"
)
var brokerLoad = make(chan bool)
var brokerConnection = make(chan bool)
var brokerClients = make(chan bool)
func brokerLoadHandler(client MQTT.Client, msg MQTT.Message) {
brokerLoad <- true
fmt.Printf("BrokerLoadHandler ")
fmt.Printf("[%s]", msg.Topic())
fmt.Printf("%s\n", msg.Payload())
}
func brokerConnectionHandler(client MQTT.Client, msg MQTT.Message) {
brokerConnection <- true
fmt.Printf("BrokerConnectionHandler ")
fmt.Printf("[%s]", msg.Topic())
fmt.Printf("%s\n", msg.Payload())
}
func brokerClientsHandler(client MQTT.Client, msg MQTT.Message) {
brokerClients <- true
fmt.Printf("BrokerClientsHandler ")
fmt.Printf("[%s]", msg.Topic())
fmt.Printf("%s\n", msg.Payload())
}
func main() {
opts := MQTT.NewClientOptions().AddBroker("tcp://iot.eclipse.org:1883").SetClientID("router-sample")
opts.SetCleanSession(true)
c := MQTT.NewClient(opts)
if token := c.Connect(); token.Wait() && token.Error() != nil {
panic(token.Error())
}
if token := c.Subscribe("$SYS/broker/load/#", 0, brokerLoadHandler); token.Wait() && token.Error() != nil {
fmt.Println(token.Error())
os.Exit(1)
}
if token := c.Subscribe("$SYS/broker/connection/#", 0, brokerConnectionHandler); token.Wait() && token.Error() != nil {
fmt.Println(token.Error())
os.Exit(1)
}
if token := c.Subscribe("$SYS/broker/clients/#", 0, brokerClientsHandler); token.Wait() && token.Error() != nil {
fmt.Println(token.Error())
os.Exit(1)
}
loadCount := 0
connectionCount := 0
clientsCount := 0
for i := 0; i < 100; i++ {
select {
case <-brokerLoad:
loadCount++
case <-brokerConnection:
connectionCount++
case <-brokerClients:
clientsCount++
}
}
fmt.Printf("Received %3d Broker Load messages\n", loadCount)
fmt.Printf("Received %3d Broker Connection messages\n", connectionCount)
fmt.Printf("Received %3d Broker Clients messages\n", clientsCount)
c.Disconnect(250)
}
</code></pre><br><br>
来源：https://www.cnblogs.com/CYD-self/p/14174133.html
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