package com.example.demo.config;

import lombok.extern.slf4j.Slf4j;
import org.eclipse.paho.client.mqttv3.*;
import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;

import javax.annotation.PostConstruct;

/**
 * @Author: xct
 * @Date: 2021/7/30 17:06
 * @Description:
 */
@Configuration
public class MqttConsumerConfig {
    @Value("${spring.mqtt.username}")
    private String username;

    @Value("${spring.mqtt.password}")
    private String password;

    @Value("${spring.mqtt.url}")
    private String hostUrl;

    @Value("${spring.mqtt.client.id}")
    private String clientId;

    @Value("${spring.mqtt.default.topic}")
    private String defaultTopic;

    /**
     * 客戶端對象
     */
    private MqttClient client;

    /**
     * 在bean初始化后連接到服務(wù)器
     * @author xct
     * @param
     * @return void
     * @date 2021/7/30 16:48
     */
    @PostConstruct
    public void init(){
        connect();
    }

    /**
     * 客戶端連接服務(wù)端
     * @author xct
     * @param
     * @return void
     * @date 2021/7/30 16:01
     */
    public void connect(){
        try {
            //創(chuàng)建MQTT客戶端對象
            client = new MqttClient(hostUrl,clientId,new MemoryPersistence());
            //連接設(shè)置
            MqttConnectOptions options = new MqttConnectOptions();
            //是否清空session，設(shè)置為false表示服務(wù)器會保留客戶端的連接記錄，客戶端重連之后能獲取到服務(wù)器在客戶端斷開連接期間推送的消息
            //設(shè)置為true表示每次連接到服務(wù)端都是以新的身份
            options.setCleanSession(true);
            //設(shè)置連接用戶名
            options.setUserName(username);
            //設(shè)置連接密碼
            options.setPassword(password.toCharArray());
            //設(shè)置超時時間，單位為秒
            options.setConnectionTimeout(100);
            //設(shè)置心跳時間 單位為秒，表示服務(wù)器每隔1.5*20秒的時間向客戶端發(fā)送心跳判斷客戶端是否在線
            options.setKeepAliveInterval(20);
            //設(shè)置遺囑消息的話題，若客戶端和服務(wù)器之間的連接意外斷開，服務(wù)器將發(fā)布客戶端的遺囑信息
            options.setWill("willTopic",(clientId + "與服務(wù)器斷開連接").getBytes(),0,false);
            //設(shè)置回調(diào)
            client.setCallback(new MqttConsumerCallBack());
            client.connect(options);
            //訂閱主題
            //消息等級，和主題數(shù)組一一對應(yīng)，服務(wù)端將按照指定等級給訂閱了主題的客戶端推送消息
            int[] qos = {1,1};
            //主題
            String[] topics = {"topic1","topic2"};
            //訂閱主題
            client.subscribe(topics,qos);
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }

    /**
     * 斷開連接
     * @author xct
     * @param
     * @return void
     * @date 2021/8/2 09:30
     */
    public void disConnect(){
        try {
            client.disconnect();
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }


    /**
     * 訂閱主題
     * @author xct
     * @param topic
     * @param qos
     * @return void
     * @date 2021/7/30 17:12
     */
    public void subscribe(String topic,int qos){
        try {
            client.subscribe(topic,qos);
        } catch (MqttException e) {
            e.printStackTrace();
        }
    }
}

package com.example.demo.config;

import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttMessage;

/**
 * @Author: xct
 * @Date: 2021/7/30 17:06
 * @Description:
 */
public class MqttConsumerCallBack implements MqttCallback {
    /**
     * 客戶端斷開連接的回調(diào)
     * @author xct
     * @param throwable
     * @return void
     * @date 2021/7/30 17:14
     */
    @Override
    public void connectionLost(Throwable throwable) {
        System.out.println("與服務(wù)器斷開連接，可重連");
    }

    /**
     * 消息到達(dá)的回調(diào)
     * @author xct
     * @param topic
     * @param message
     * @return void
     * @date 2021/7/30 17:14
     */
    @Override
    public void messageArrived(String topic, MqttMessage message) throws Exception {
        System.out.println(String.format("接收消息主題 : %s",topic));
        System.out.println(String.format("接收消息Qos : %d",message.getQos()));
        System.out.println(String.format("接收消息內(nèi)容 : %s",new String(message.getPayload())));
        System.out.println(String.format("接收消息retained : %b",message.isRetained()));
        //TODO 可以將消息持久化到數(shù)據(jù)庫中，然后在進(jìn)行其他操作。
    }

    /**
     * 消息發(fā)布成功的回調(diào)
     * @author xct
     * @param iMqttDeliveryToken
     * @return void
     * @date 2021/7/30 17:14
     */
    @Override
    public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {

    }
}

package com.example.demo.controller;


import com.example.demo.config.MqttConsumerConfig;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

/**
 * @Author: xct
 * @Date: 2021/7/30 17:20
 * @Description:
 */
@Controller
public class TestController {
    @Autowired
    private MqttConsumerConfig client;

    @Value("${spring.mqtt.client.id}")
    private String clientId;

    @RequestMapping("connect")
    @ResponseBody
    public String connect(){
        client.connect();
        return clientId + "連接到服務(wù)器";
    }

    @RequestMapping("disConnect")
    @ResponseBody
    public String disConnect(){
        client.disConnect();
        return clientId + "與服務(wù)器斷開連接";
    }
}

spring:
  application:
    name: consumer
#MQTT配置信息
  mqtt:
#MQTT服務(wù)端地址，端口默認(rèn)為1883，如果有多個，用逗號隔開，如tcp://127.0.0.1:1883,tcp://192.168.60.133:1883
    url: tcp://0.0.0.0:1883
#用戶名
    username: admin
#密碼
    password: public
#客戶端id（不能重復(fù)）
    client:
      id: consumer-id
#MQTT默認(rèn)的消息推送主題，實(shí)際可在調(diào)用接口時指定
    default:
      topic: topic
server:
   port: 8082