我正在尝试使用mosquitto代理运行基本队列实现,当使用者和生产者正常运行时,它可以正常工作。如果我运行生产者,然后运行消费者,则无法获取消息(数据)。在将消息发布到主题时,我正在使用qos:2。我在mqtt.js中使用nodejs语言
consumer.js
const mqtt = require ('mqtt');
var options = {}
options.clientId = 'mqttjs_consumer'
options.clean = false
options.debug = true
var client = mqtt.connect('mqtt://localhost',options);
client.on('connect', function () {
client.subscribe('topic/sample',function(){
console.log('client has subscribed successfully');
});
});
client.on('message', function (topic, message){
console.log(message.toString());
});
Producer.js
const mqtt = require ('mqtt');
var options = {}
options.clientId = 'mqttjs_producer'
options.debug = true
var client = mqtt.connect('mqtt://localhost',options);
client.on('connect', function(){
client.publish('topic/sample','message_data',{qos:2},function(err,status){
console.log(err,status)
process.exit(0)
})
});
答案 0 :(得分:0)
您需要在QOS 2上订阅,而不仅仅是在QOS 2上发布。
const mqtt = require ('mqtt');
var options = {}
options.clientId = 'mqttjs_consumer'
options.clean = false
options.debug = true
var client = mqtt.connect('mqtt://localhost',options);
client.on('connect', function () {
client.subscribe('topic/sample',{qos:2}, function(){
console.log('client has subscribed successfully');
});
});
client.on('message', function (topic, message){
console.log(message.toString());
});