RabbitMQ开启MQTT协议支持

1）RabbitMQ启用MQTT插件

root@mq:/# rabbitmq-plugins enable rabbitmq_mqtt
Enabling plugins on node rabbit@mq:
rabbitmq_mqtt
The following plugins have been configured:
  rabbitmq_management
  rabbitmq_management_agent
  rabbitmq_mqtt
  rabbitmq_web_dispatch
Applying plugin configuration to rabbit@mq...
The following plugins have been enabled:
  rabbitmq_mqtt

started 1 plugins.
root@mq:/# rabbitmq-plugins enable rabbitmq_web_mqtt
Enabling plugins on node rabbit@mq:
rabbitmq_web_mqtt
The following plugins have been configured:
  rabbitmq_management
  rabbitmq_management_agent
  rabbitmq_mqtt
  rabbitmq_web_dispatch
  rabbitmq_web_mqtt
Applying plugin configuration to rabbit@mq...
The following plugins have been enabled:
  rabbitmq_web_mqtt

started 1 plugins.
root@mq:/# 

2）RabbitMQ管理控制台查看
如果插件启动成功，rabbitmq会打开1883和15675端口：

3）用MQTTX工具测试

4）用eclipse paho客户端测试
添加依赖

 <dependency>
    <groupId>org.eclipse.paho</groupId>
    <artifactId>org.eclipse.paho.client.mqttv3</artifactId>
    <version>1.2.5</version>
</dependency>

收发消息测试

@RestController
public class DemoController {

    @GetMapping("/publish")
    public String publish() throws MqttException {

        MqttClientPersistence persistence = new MemoryPersistence();;//内存持久化
        MqttClient client = new MqttClient("tcp://192.168.137.138:1883", "abc", persistence);

        //连接选项中定义用户名密码和其它配置
        MqttConnectOptions options = new MqttConnectOptions();
        options.setCleanSession(true);//参数为true表示清除缓存，也就是非持久化订阅者，这个时候只要参数设为true，一定是非持久化订阅者。而参数设为false时，表示服务器保留客户端的连接记录
        options.setAutomaticReconnect(true);//是否自动重连
        options.setConnectionTimeout(30);//连接超时时间  秒
        options.setKeepAliveInterval(10);//连接保持检查周期  秒
        options.setMqttVersion(MqttConnectOptions.MQTT_VERSION_3_1_1); //版本
        options.setUserName("xjs1919");
        options.setPassword("123321".toCharArray());
        // client.setManualAcks(true);
        client.connect(options);//连接
        //订阅topic
        client.subscribe("demoTopic", 2);
        // 设置回调，将来收到消息的时候会被回调
        client.setCallback(new MqttCallbackExtended() {
            @Override
            public void connectComplete(boolean reconnect, String serverURI) {
                System.out.println("连接完成");
            }

            @Override
            public void connectionLost(Throwable cause) {
                System.out.println("连接丢失");
            }

            @Override
            public void messageArrived(String topic, MqttMessage message) throws Exception {
                System.out.println("收到消息，topic："+topic + ", msg:" + new String(message.getPayload()));
                //client.messageArrivedComplete(message.getId(),message.getQos());
            }

            @Override
            public void deliveryComplete(IMqttDeliveryToken token) {
                // Qos0: 当消息发送出去就回调
                // Qos1: 当发送者收到了puback的时候的回调
                // Qos2: 当发送者收到了pubcomp的时候的回调
                System.out.println("消息发送完成");
            }
        });

        client.publish("demoTopic", "hello,这是一个测试消息!".getBytes(), 2, false);

        return "ok";
    }

}

参考文章：
https://www.cnblogs.com/motion/p/14974024.html
https://blog.csdn.net/u013615903/article/details/131395264