MQTT接受消息数据

最新推荐文章于 2025-04-18 11:58:57 发布

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最新推荐文章于 2025-04-18 11:58:57 发布

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分类专栏：后端文章标签： MQTT

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在初次接触MQTT协议时，由于数据对接，从rabbitMQ接收的消息是以16进制形式展示的非预期数字。经过排查，了解到这些数据需要转换为ASCII字符串。使用了相关jar包，包括hawtbuf-1.9.jar, hawtdispatch-1.22.jar, hawtdispatch-transport-1.22.jar, mqtt-client-1.15.jar进行处理。" 80693446,7355710,新浪体育直播爬取：篮球足球数据抓取与解析,"['Python爬虫', '数据抓取', '网络爬虫', 'HTML解析', '网页结构分析']

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之前未接触过MQTT协议，前几天因为数据对接，提供方是rabbitMQ 使用MQTT协议发布的消息，接收到消息后发现不是预期的数据，一堆数字，折腾了两三个小时发现是16进制的数据，最后转换成ascii字符串。



import java.net.URISyntaxException;

import org.apache.commons.codec.binary.Hex;
import org.fusesource.mqtt.client.Future;  
import org.fusesource.mqtt.client.FutureConnection;  
import org.fusesource.mqtt.client.MQTT;  
import org.fusesource.mqtt.client.Message;  
import org.fusesource.mqtt.client.QoS;  
import org.fusesource.mqtt.client.Topic;  
  
/** 
 * 采用Future模式 订阅主题   
 */  
public class MQTTFutureClient {  
  
    private final static String CONNECTION_STRING = "tcp://00.00.00.00:xxxx";  
    private final static boolean CLEAN_START = true;  
    private final static short KEEP_ALIVE = 30;// 低耗网络，但是又需要及时获取数据，心跳30s  
    private final static String CLIENT_ID = "22028197";  
    public static Topic[] topics = {   
        new Topic("artemis/event_face/3187675137/admin", QoS.AT_LEAST_ONCE)};  
      
    public final static long RECONNECTION_ATTEMPT_MAX = 6;  
    public final static long RECONNECTION_DELAY = 2000;  
  
    public final static int SEND_BUFFER_SIZE = 2 * 1024 * 1024;// 发送最大缓冲为2M  
  
    public static void main(String[] args) {  
        // 创建MQTT对象  
        MQTT mqtt = new MQTT();  
        try {  
            // 设置mqtt broker的ip和端口  
            mqtt.setHost(CONNECTION_STRING);  
            // 连接前清空会话信息  
            mqtt.setCleanSession(CLEAN_START);  
            // 设置重新连接的次数  
            mqtt.setReconnectAttemptsMax(RECONNECTION_ATTEMPT_MAX);  
            // 设置重连的间隔时间  
            mqtt.setReconnectDelay(RECONNECTION_DELAY);  
            // 设置心跳时间  
            mqtt.setKeepAlive(KEEP_ALIVE);  
            // 设置缓冲的大小  
            mqtt.setSendBufferSize(SEND_BUFFER_SIZE);  
            //设置客户端id  
            mqtt.setClientId(CLIENT_ID);  
            mqtt.setUserName("artemis_22028197_15BPX2S5");
            mqtt.setPassword("XT9HO0RL");
  
            // 获取mqtt的连接对象BlockingConnection  
            final FutureConnection connection = mqtt.futureConnection();  
            connection.connect();  
            connection.subscribe(topics);  
            while (true) {  
                Future<Message> futrueMessage = connection.receive();  
                Message message = futrueMessage.await(); 
                System.out.println(message.getPayloadBuffer());
                
                String msg = String.valueOf(message.getPayloadBuffer());
                String jsonStr = "";
                if(msg.substring(0, 3).equals("hex")) {
              	  msg=msg.substring(5);
                	byte[] bytes=Hex.decodeHex(msg.toCharArray());
                	jsonStr =  new String(bytes,"GBK");
                	System.out.println(jsonStr);
                }else {
                	jsonStr = msg.substring(7);
                	System.out.println(jsonStr);
                }
                
            }  
        }  catch (URISyntaxException e) {  
            e.printStackTrace();  
        } catch (Exception e) {  
            e.printStackTrace();  
        } finally {  
        }  
    }

}