MQTT Java客户端Eclipse paho实现数据的发送和接收

MQTT(MQ Telemetry Transport)是IBM开发的一种网络应用层的协议

使用场景：

1、不可靠、网络带宽小的网络

2、运行的设备CPU、内存非常有限

特点：

1、基于发布/订阅模型的协议

2、他是二进制协议，二进制的特点就是紧凑、占用空间小。他的协议头只有2个字节

3、提供了三种消息可能性保障：最多一次 0、最少一次 1、只有一次 2

maven依赖

<dependency><groupId>org.eclipse.paho</groupId><artifactId>org.eclipse.paho.client.mqttv3</artifactId><version>1.1.1</version></dependency>

发送消息示例

import org.eclipse.paho.client.mqttv3.IMqttDeliveryToken;import org.eclipse.paho.client.mqttv3.MqttCallback;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.MqttMessage;import org.eclipse.paho.client.mqttv3.MqttPersistenceException;import org.eclipse.paho.client.mqttv3.persist.MemoryPersistence;/** * 发送数据到mqtt服务器 * @author：涂有 * @date 2017年8月16日 下午11:15:22 */public class PubMsg {private static int qos = 2; //只有一次private static String broker = "tcp://10.100.124.206:1883";private static String userName = "tuyou";private static String passWord = "tuyou";private static MqttClient connect(String clientId,String userName,String password) throws MqttException {MemoryPersistence persistence = new MemoryPersistence();MqttConnectOptions connOpts = new MqttConnectOptions();connOpts.setCleanSession(true);connOpts.setUserName(userName);connOpts.setPassword(password.toCharArray());connOpts.setConnectionTimeout(10);connOpts.setKeepAliveInterval(20);//String[] uris = {"tcp://10.100.124.206:1883","tcp://10.100.124.207:1883"};//connOpts.setServerURIs(uris);  //起到负载均衡和高可用的作用MqttClient mqttClient = new MqttClient(broker, clientId, persistence);mqttClient.setCallback(new PushCallback("test"));mqttClient.connect(connOpts);return mqttClient;}private static void pub(MqttClient sampleClient, String msg,String topic) throws MqttPersistenceException, MqttException {MqttMessage message = new MqttMessage("ertwersdfas".getBytes());message.setQos(qos);message.setRetained(false);sampleClient.publish(topic, message);}private static void publish(String str,String clientId,String topic) throws MqttException{MqttClient mqttClient = connect(clientId,userName,passWord);if (mqttClient != null) {pub(mqttClient, str, topic);System.out.println("pub-->" + str);}if (mqttClient != null) {mqttClient.disconnect();}}public static void main(String[] args) throws MqttException {publish("message content","client-id-0","$share/edge/server/public/a");}}class PushCallback implements MqttCallback {private String threadId;public PushCallback(String threadId){this.threadId = threadId;}    public void connectionLost(Throwable cause) {        }    public void deliveryComplete(IMqttDeliveryToken token) {//       System.out.println("deliveryComplete---------" + token.isComplete());    }    public void messageArrived(String topic, MqttMessage message) throws Exception {    String msg = new String(message.getPayload());    System.out.println(threadId + " " + msg);    }}

消费消息示例

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;public class SubMsg {// private static String topic = "$share/testgroup/wyptest1";// private static String topic = "$queue/wyptest1";// private static String topic = "wyptest1";     private static int qos = 2;     private static String broker = "tcp://10.100.124.207:1883";     private static String userName = "tuyou";     private static String passWord = "tuyou";         private static MqttClient connect(String clientId) throws MqttException{     MemoryPersistence persistence = new MemoryPersistence();     MqttConnectOptions connOpts = new MqttConnectOptions();//     String[] uris = {"tcp://10.100.124.206:1883","tcp://10.100.124.206:1883"};     connOpts.setCleanSession(false);         connOpts.setUserName(userName);         connOpts.setPassword(passWord.toCharArray());         connOpts.setConnectionTimeout(10);         connOpts.setKeepAliveInterval(20);//         connOpts.setServerURIs(uris);//         connOpts.setWill(topic, "close".getBytes(), 2, true);         MqttClient mqttClient = new MqttClient(broker, clientId, persistence);         mqttClient.connect(connOpts);     return mqttClient;     }          public static void sub(MqttClient mqttClient,String topic) throws MqttException{         int[] Qos  = {qos};         String[] topics = {topic};         mqttClient.subscribe(topics, Qos);     }              private static void runsub(String clientId, String topic) throws MqttException{    MqttClient mqttClient = connect(clientId);    if(mqttClient != null){sub(mqttClient,topic);    }    }    public static void main(String[] args) throws MqttException{    runsub("client-id-1", "$share/testgroupa/edge/server/private/+");    }}