mqtt的使用

  
        <dependency>
            <groupId>org.springframework.integrationgroupId>
            <artifactId>spring-integration-streamartifactId>
        dependency>
        <dependency>
            <groupId>org.springframework.integrationgroupId>
            <artifactId>spring-integration-mqttartifactId>
        dependency>

mqtt:
  enabled: true
  host: tcp://localhost:1883
  username: admin
  pwd: admin

package com.zhk.study.mqtt;

import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.mqtt.core.DefaultMqttPahoClientFactory;
import org.springframework.integration.mqtt.core.MqttPahoClientFactory;


/**
 * mqtt消息处理配置
 */
@Configuration
@ConditionalOnProperty(value = "mqtt.enabled", havingValue = "true")
public class MqttBaseConfig {
    @Value("${mqtt.host}")
    private String mqttHost;

    @Value("${mqtt.username:}")
    private String mqttUserName;

    @Value("${mqtt.pwd:}")
    private String mqttPwd;

    /**
     * 构造一个默认的mqtt客户端操作bean
     *
     * @return
     */
    @Bean
    public MqttPahoClientFactory factory(){
	  DefaultMqttPahoClientFactory defaultMqttPahoClientFactory = new DefaultMqttPahoClientFactory();
	  MqttConnectOptions mqttConnectOptions = new MqttConnectOptions();
	  mqttConnectOptions.setUserName(mqttUserName);
	  mqttConnectOptions.setPassword(mqttPwd.toCharArray());
	  mqttConnectOptions.setServerURIs(new String[]{mqttHost});
	  defaultMqttPahoClientFactory.setConnectionOptions(mqttConnectOptions);
	  return defaultMqttPahoClientFactory;
    }

}

package com.zhk.study.mqtt;


import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.mqtt.core.MqttPahoClientFactory;
import org.springframework.integration.mqtt.outbound.MqttPahoMessageHandler;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;

/**
 * mqtt出站消息处理配置
 */
@Configuration
@ConditionalOnProperty(value = "mqtt.enabled", havingValue = "true")
public class MqttOutConfig {

    /**
     * mqtt消息出站通道，用于发送出站消息
     *
     * @return
     */
    @Bean
    public MessageChannel mqttOutputChannel() {
	  return new DirectChannel();
    }

    /**
     * mqtt消息出站通道默认配置，用于向外发出mqtt消息，当前案例中发到了同一个mqtt服务器
     *
     * @return
     */
    @Bean
    @ServiceActivator(inputChannel = "mqttOutputChannel")
    public MessageHandler mqttOutbound(MqttPahoClientFactory factory) {
	  String clientId = "h-backend-mqtt-out-" + System.currentTimeMillis();
	  MqttPahoMessageHandler messageHandler = new MqttPahoMessageHandler(clientId, factory);
	  messageHandler.setAsync(true);
	  messageHandler.setDefaultQos(2);
	  messageHandler.setDefaultTopic("/crane/mqtt/demo/foo");
	  return messageHandler;
    }
}

package com.zhk.study.mqtt;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.integration.mqtt.support.MqttHeaders;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageHandler;
import org.springframework.messaging.MessagingException;
import org.springframework.stereotype.Component;

/**
 * mqtt订阅消息处理
 */
@Component
@ConditionalOnProperty(value = "mqtt.enabled", havingValue = "true")
public class MqttMessageReceiver implements MessageHandler {
    private Logger logger = LoggerFactory.getLogger(this.getClass());

    @Override
    public void handleMessage(Message<?> message) throws MessagingException {
	  String topic = String.valueOf(message.getHeaders().get(MqttHeaders.RECEIVED_TOPIC));
	  String payload = String.valueOf(message.getPayload());
	  logger.info("接收到 mqtt消息，主题:{} 消息:{}", topic, payload);
    }
}

package com.zhk.study.mqtt;

import lombok.RequiredArgsConstructor;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.integration.annotation.ServiceActivator;
import org.springframework.integration.channel.DirectChannel;
import org.springframework.integration.core.MessageProducer;
import org.springframework.integration.mqtt.core.MqttPahoClientFactory;
import org.springframework.integration.mqtt.inbound.MqttPahoMessageDrivenChannelAdapter;
import org.springframework.integration.mqtt.support.DefaultPahoMessageConverter;
import org.springframework.messaging.MessageChannel;
import org.springframework.messaging.MessageHandler;

@Configuration
@ConditionalOnProperty(value = "mqtt.enabled", havingValue = "true")
@RequiredArgsConstructor
public class MqttInConfig {

    private final MqttMessageReceiver mqttMessageReceiver;

    /**
     * mqtt消息入站通道，订阅消息后消息进入的通道。
     * 可创建多个入站通道，对应多个不同的消息生产者。
     *
     * @return
     */
    @Bean
    public MessageChannel mqttInputChannel() {
        return new DirectChannel();
    }
    /**
     * 对于当前应用来讲，接收的mqtt消息的生产者。将生产者绑定到mqtt入站通道，即通过入站通道进入的消息为生产者生产的消息。
     * 可创建多个消息生产者，对应多个不同的消息入站通道，同时生产者监听不同的topic
     *
     * @return
     */
    @Bean
    public MessageProducer channelInbound(MessageChannel mqttInputChannel, MqttPahoClientFactory factory) {
	  String clientId = "h-backend-mqtt-in-" + System.currentTimeMillis();
	  MqttPahoMessageDrivenChannelAdapter adapter = new MqttPahoMessageDrivenChannelAdapter(clientId, factory, "/crane/mqtt/demo/#");
	  adapter.setCompletionTimeout(5000);
	  adapter.setConverter(new DefaultPahoMessageConverter());
	  adapter.setQos(2);
	  adapter.setOutputChannel(mqttInputChannel);
	  return adapter;
    }
    /**
     * mqtt入站消息处理工具，对于指定消息入站通道接收到生产者生产的消息后处理消息的工具。
     *
     * @return
     */
    @Bean
    @ServiceActivator(inputChannel = "mqttInputChannel")
    public MessageHandler mqttMessageHandler() {
	  return this.mqttMessageReceiver;
    }


}

package com.zhk.study.mqtt;


import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.integration.annotation.MessagingGateway;
import org.springframework.integration.mqtt.support.MqttHeaders;
import org.springframework.messaging.handler.annotation.Header;
import org.springframework.stereotype.Component;

/**
 * mqtt消息发送工具，指定通过某个通道发出消息
 */
@Component
@ConditionalOnProperty(value = "mqtt.enabled", havingValue = "true")
@MessagingGateway(defaultRequestChannel = "mqttOutputChannel")
public interface MqttMessageSender {
    /**
     * 发送信息
     *
     * @param data 发送的消息
     */
    void sendToMqtt(String data);

    /**
     * 指定主题发送消息
     *
     * @param topic   主题
     * @param payload 消息主体
     */
    void sendToMqtt(@Header(MqttHeaders.TOPIC) String topic, String payload);

    /**
     * 指定主题、qos发送消息
     *
     * @param topic   主题
     * @param qos     对消息处理的几种机制。
     *                0 表示的是订阅者没收到消息不会再次发送，消息会丢失。
     *                1 表示的是会尝试重试，一直到接收到消息，但这种情况可能导致订阅者收到多次重复消息。
     *                2 多了一次去重的动作，确保订阅者收到的消息有一次。
     * @param payload 消息主体
     */
    void sendToMqtt(@Header(MqttHeaders.TOPIC) String topic, @Header(MqttHeaders.QOS) int qos, String payload);

}

package com.zhk.study.mqtt;


import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@ConditionalOnProperty(value = "mqtt.enabled", havingValue = "true")
@RequestMapping("/public/mqtt")
public class MqttController {
    private Logger logger = LoggerFactory.getLogger(this.getClass());
    private final MqttMessageSender mqttMessageSender;

    public MqttController(MqttMessageSender mqttMessageSender) {
	  this.mqttMessageSender = mqttMessageSender;
    }

    /**
     * 发送mqtt消息
     *
     * @param topic 消息主题
     * @param data  消息内容
     * @return
     */
    @GetMapping("/send")
    public String send(String topic, String data) {

	  if (StringUtils.isNotBlank(topic)) {
		this.mqttMessageSender.sendToMqtt(topic, data);
	  } else {
		this.mqttMessageSender.sendToMqtt(data);
	  }

	  return "success";
    }
}

疑问点可以直接给博主发消息，看到就回复，此帖转发别人的。注意点这个监听绑定在MqttInConfig中
MqttPahoMessageDrivenChannelAdapter adapter = new MqttPahoMessageDrivenChannelAdapter(clientId, factory, "/crane/mqtt/demo/#");