MQTT服务搭建与SpringBoot简单实现
一、MQTT服务器搭建
- 下载MQTT Broker
https://www.emqx.com/zh/try?product=broker
- 解压缩，启动emqx，查看状态，重置Dashboard密码
emqx.cmd start
emqx_ctl.cmd status
emqx_ctl.cmd admins passwd admin 123456
- 登录MQTT服务器控制台
http://127.0.0.1:18083
4. 使用指南
https://www.emqx.io/docs/zh/latest/
二、MQTT客户端使用
- 下载MQTT Client
https://www.emqx.com/zh/try?product=MQTTX
三、Java连接MQTT
- 创建两个微服务MqttProviderApp和MqttConsumerApp作为Mqtt消息提供方和消费方；
<parent>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-parentartifactId>
<version>2.1.6.RELEASEversion>
parent>
<dependencies>
<dependency>
<groupId>org.springframework.integrationgroupId>
<artifactId>spring-integration-mqttartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
dependencies>
- 启动类
@SpringBootApplication
public class MqttProviderApp {
public static void main(String[] args) {
SpringApplication.run(MqttProviderApp.class, args);
}
}
- 配置
(1) application.yml
# MqttProviderApp
spring:
application:
name: mqtt-provider
mqtt:
url: tcp://localhost:1883
username: admin
password: 123456
client:
id: provider-id
default:
topic: topic
server:
port: 60001
#MqttConsumerApp
spring:
application:
name: mqtt-consumer
mqtt:
url: tcp://127.0.0.1:1883
username: admin
password: 123456
client:
id: consumer-id
default:
topic: topic
server:
port: 60002
(2) 配置类
//MqttProviderApp
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;
@Slf4j
@Configuration
public class MqttProviderConfig {
@Value("${mqtt.username}")
private String username;
@Value("${mqtt.password}")
private String password;
@Value("${mqtt.url}")
private String url;
@Value("${mqtt.client.id}")
private String clientId;
@Value("${mqtt.default.topic}")
private String defaultTopic;
private MqttClient client;
/**
* Bean初始化后连接到服务器
*/
@PostConstruct
public void init() {
connect();
}
/**
* 配置Mqtt客户端对象
*/
public void connect() {
try {
client = new MqttClient(url, clientId, new MemoryPersistence());
MqttConnectOptions options = new MqttConnectOptions();
//是否清空session，设置false表示服务器会保留客户端的连接记录（订阅主题，qos）
//客户端重连之后能获取到服务器在客户端断开连接期间推送的消息,
//设置为true表示每次连接服务器都是新身份
options.setCleanSession(true);
options.setUserName(username);
options.setPassword(password.toCharArray());
//连接超时，单位为秒
options.setConnectionTimeout(100);
//设置心跳时间 单位为秒，表示服务器每隔 1.5*20秒的时间向客户端发送心跳判断客户端是否在线
options.setKeepAliveInterval(20);
//设置遗嘱消息的话题，若客户端和服务器之间的连接意外断开，服务器将发布客户端的遗嘱信息
//QoS服务质量，QoS0至多一次，QoS1至少一次，QoS2只有一次
options.setWill("willTopic", (clientId + "与服务器断开连接").getBytes(), 0, false);
client.setCallback(new MqttProviderCallback());
client.connect(options);
} catch (MqttException e) {
log.error("Mqtt Server has broken.");
}
}
public void publish(String topic, String message, int qos, boolean retained) {
MqttMessage mqttMessage = new MqttMessage();
mqttMessage.setQos(qos);
mqttMessage.setRetained(retained);
mqttMessage.setPayload(message.getBytes());
MqttTopic mqttTopic = client.getTopic(topic);
//提供一种机制跟踪消息的传递进度，以非阻塞方式执行发布时跟踪消息的传递进度
MqttDeliveryToken token;
try {
//将指定消息发布到主题，但不等待消息传递完成，返回的token可用于跟踪消息的传递状态
token = mqttTopic.publish(mqttMessage);
token.waitForCompletion();
} catch (MqttException e) {
log.info("Mqtt publish failed.");
}
}
}
import lombok.extern.slf4j.Slf4j;
import org.eclipse.paho.client.mqttv3.IMqttAsyncClient;
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.springframework.beans.factory.annotation.Value;
@Slf4j
public class MqttProviderCallback implements MqttCallback {
@Value("${mqtt.client.id}")
private String clientId;
@Override
public void connectionLost(Throwable throwable) {
//与服务器断开的回调
log.info(clientId + "与服务器断开连接");
}
@Override
public void messageArrived(String s, MqttMessage mqttMessage) throws Exception {
//消息到达的回调
log.info("Message Arrived.");
}
@Override
public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {
//消息发布成功的回调
IMqttAsyncClient client = iMqttDeliveryToken.getClient();
log.info(client.getClientId() + "发布消息成功！");
}
}
//MqttConsumerApp
import lombok.extern.slf4j.Slf4j;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.eclipse.paho.client.mqttv3.MqttException;
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;
@Slf4j
@Configuration
public class MqttConsumerConfig {
@Value("${mqtt.username}")
private String username;
@Value("${mqtt.password}")
private String password;
@Value("${mqtt.url}")
private String url;
@Value("${mqtt.client.id}")
private String clientId;
@Value("${mqtt.default.topic}")
private String defaultTopic;
private MqttClient client;
@PostConstruct
public void init() {
connect();
}
/**
* 配置Mqtt客户端对象
*/
public void connect() {
try {
client = new MqttClient(url, clientId, new MemoryPersistence());
MqttConnectOptions options = new MqttConnectOptions();
//是否清空session，设置false表示服务器会保留客户端的连接记录（订阅主题，qos）
//客户端重连之后能获取到服务器在客户端断开连接期间推送的消息,
//设置为true表示每次连接服务器都是新身份
options.setCleanSession(true);
options.setUserName(username);
options.setPassword(password.toCharArray());
//连接超时，单位为秒
options.setConnectionTimeout(100);
//设置心跳时间 单位为秒，表示服务器每隔 1.5*20秒的时间向客户端发送心跳判断客户端是否在线
options.setKeepAliveInterval(20);
//设置遗嘱消息的话题，若客户端和服务器之间的连接意外断开，服务器将发布客户端的遗嘱信息
//QoS服务质量，QoS0至多一次，QoS1至少一次，QoS2只有一次
options.setWill("willTopic", (clientId + "与服务器断开连接").getBytes(), 0, false);
client.setCallback(new MqttConsumerCallback());
client.connect(options);
//订阅主题 消息等级和主题数组一一对应，服务端将按照指定等级给订阅了主题的客户端推送消息
int[] qos = {1, 1};
String[] topics = {"topic1", "topic2"};
client.subscribe(topics, qos);
} catch (MqttException e) {
log.error("Mqtt Server has broken.");
}
}
/**
* 断开连接
*/
public void disconnect() {
try {
client.disconnect();
} catch (MqttException e) {
log.error("Mqtt Server has broken.");
}
}
}
import lombok.extern.slf4j.Slf4j;
import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttMessage;
@Slf4j
public class MqttConsumerCallback implements MqttCallback {
@Override
public void connectionLost(Throwable throwable) {
//客户端断开连接后回调
log.info("与服务器断开连接，可重连");
}
@Override
public void messageArrived(String topic, MqttMessage mqttMessage) throws Exception {
log.info("接收消息主题：{}，QoS：{}，消息内容：{}，消息retained：{}", topic,
mqttMessage.getQos(), new String(mqttMessage.getPayload()), mqttMessage.isRetained());
}
@Override
public void deliveryComplete(IMqttDeliveryToken iMqttDeliveryToken) {
//消息发布成功回调
}
}
(3) 测试接口
//MqttProviderApp
import org.lxx.stream.mqtt.provider.config.MqttProviderConfig;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class SendController {
@Autowired
private MqttProviderConfig providerClient;
@GetMapping("sendMessage")
public String sendMessage(String topic, String message, int qos, boolean retained) {
providerClient.publish(topic, message, qos, retained);
return "发送成功";
}
}
//MqttConsumerApp
@RestController
public class ReceiveController {
@Autowired
private MqttConsumerConfig client;
@Value("${mqtt.client.id}")
private String clientId;
@GetMapping("connect")
public String connect() {
client.connect();
return client + "连接到服务器";
}
@GetMapping("disconnect")
public String disconnect() {
client.disconnect();
return clientId + "与服务器断开连接";
}
}
(4) Postman测试
提供方生产消息：
curl --location --request GET 'http://localhost:60001/sendMessage?qos=1&retained=false&topic=topic1&message=Hello%20MQTT!'
消费方断开连接：
curl --location --request GET 'http://localhost:60002/disconnect'
消费方重新连接：
curl --location --request GET 'http://localhost:60002/connect'
