Java mqtt中包含多个主题的一个代理url

我有两个主题和一个代理URL。我需要使用一个代理URL发布到这两个主题

我使用了一个代理URL和一个主题。然后我尝试处理两个主题，并为每个主题编写两个订户类，但当我运行两个订户类时，其中一个将显示连接丢失。 建议一些好的例子来做这件事

MQTTPublisher.java

import java.io.BufferedReader;
import java.io.InputStreamReader;

import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttClientPersistence;
import org.eclipse.paho.client.mqttv3.MqttDefaultFilePersistence;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.MqttTopic;

public class MQTTPublisher {


static final String BROKER_URL = "tcp://localhost:1883";// public mosquitto
                                                        // server
static final String TOPIC = "iotm/ej";// Change according to your
                                            // application
static final String TOPIC1 = "iotm/stream1";

public static void main(String args[]) {

    try {
        // Creating new default persistence for mqtt client
        MqttClientPersistence persistence = new MqttDefaultFilePersistence(
                "/tmp");

        // mqtt client with specific url and client id
        MqttClient client1 = new MqttClient(BROKER_URL, "Publisher-ID",
                persistence);

        client.connect();

        MqttTopic myTopic = client1.getTopic(TOPIC);
        MqttTopic myTopic1 = client1.getTopic(TOPIC1);
        String msg = "AMMA!DEVI!dURGA";
         System.out.println("Enter the message to publish,Type quit to exit\n");
         BufferedReader br = new BufferedReader(new
         InputStreamReader(System.in));
         msg = br.readLine();
         while (!msg.equals("quit")) {
         myTopic.publish(new MqttMessage(msg.getBytes()));
         System.out.println("Message published on" + TOPIC);
         myTopic1.publish(new MqttMessage(msg.getBytes()));

         System.out.println("Message published on" + TOPIC1);
         msg = br.readLine();
         }
        myTopic.publish(new MqttMessage(msg.getBytes()));

        myTopic1.publish(new MqttMessage(msg.getBytes()));

        // client.disconnect();
    } catch (MqttException e) {
        e.printStackTrace();
    } catch (Exception e) {
        System.err.println(e.getMessage());
    }
}
}

MQTTSubscriber.java

import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttDefaultFilePersistence;
import org.eclipse.paho.client.mqttv3.MqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.MqttTopic;

public class MQTTSubscriber {

static final String BROKER_URL = "tcp://localhost:1883";// public
// mosquitto server
static final String TOPIC = "iotm/ej"; // Change according to your



public static void main(String args[]) {

    try {
        // Creating new default persistence for mqtt client
        MqttDefaultFilePersistence persistence = new MqttDefaultFilePersistence(
                "/tmp");

        // mqtt client with specific url and a random client id
        MqttClient client1 = new MqttClient(BROKER_URL, "Subscriber-ID",
                persistence);
        client1.connect();
        System.out.println("Subscribing to topic '" + TOPIC + "' from "
                + client1.getServerURI());
        // Subscribing to specific topic
        client1.subscribe(TOPIC);

        // It will trigger when a new message is arrived
        MqttCallback callback = new MqttCallback() {
            @Override
            public void messageArrived(MqttTopic arg0, MqttMessage arg1)
                    throws Exception {
                System.out.println("Message:"
                        + new String(arg1.getPayload()));

            }

            @Override
            public void deliveryComplete(MqttDeliveryToken arg0) {

            }

            @Override
            public void connectionLost(Throwable arg0) {
                System.out.println("Connection lost");
            }
        };
        // Continue waiting for messages until the Enter is pressed
        client1.setCallback(callback);
        /*
         * System.out.println("Press <Enter> to exit"); try {
         * System.in.read(); } catch (IOException e) { // If we can't read
         * we'll just exit }
         */
        // client.disconnect();
        // System.out.println("Client Disconnected");

    } catch (MqttException e) {
        e.printStackTrace();
    } catch (Exception e) {
        System.err.println(e.getMessage());
    }
}

}

import org.eclipse.paho.client.mqttv3.MqttCallback；
导入org.eclipse.paho.client.mqttv3.MqttClient；
导入org.eclipse.paho.client.mqttv3.MqttDefaultFilePersistence；
导入org.eclipse.paho.client.mqttv3.MqttDeliveryToken；
导入org.eclipse.paho.client.mqttv3.MqttException；
导入org.eclipse.paho.client.mqttv3.MqttMessage；
导入org.eclipse.paho.client.mqttv3.MqttTopic；
公共类MQTTSubscriber{
静态最终字符串BROKER_URL=”tcp://localhost:1883“；//公开
//MOSQUITO服务器
静态最终字符串TOPIC=“iotm/ej”；//根据您的
公共静态void main（字符串参数[]）{
试一试{
//为mqtt客户机创建新的默认持久性
MqttDefaultFilePersistence persistence=新MqttDefaultFilePersistence(
“/tmp”）；
//具有特定url和随机客户端id的mqtt客户端
MqttClient client1=新MqttClient（代理URL，“订户ID”，
持久性）；
client1.connect（）；
System.out.println（“订阅主题”’+topic+“'from”
+client1.getServerURI（））；
//订阅特定主题
客户1.订阅（主题）；
//它将在新消息到达时触发
MqttCallback callback=新的MqttCallback（）{
@凌驾
public void messageArrived（MqttTopic arg0、MqttMessage arg1）
抛出异常{
System.out.println（“消息：
+新字符串（arg1.getPayload（））；
}
@凌驾
公共无效交付完成（MqttDeliveryToken arg0）{
}
@凌驾
public void connectionLost（可丢弃arg0）{
System.out.println（“连接丢失”）；
}
};
//继续等待消息，直到按Enter键
client1.setCallback（callback）；
/*
*System.out.println（“按下退出”）；尝试{
*System.in.read（）；}catch（IOException e）{//如果我们无法读取
*我们就退出}
*/
//client.disconnect（）；
//System.out.println（“客户端断开”）；
}捕获（MqttException e）{
e、 printStackTrace（）；
}捕获（例外e）{
System.err.println（e.getMessage（））；
}
}
}

MQTTSubscriber2.java

import org.eclipse.paho.client.mqttv3.MqttCallback;
import org.eclipse.paho.client.mqttv3.MqttClient;
import org.eclipse.paho.client.mqttv3.MqttDefaultFilePersistence;
import org.eclipse.paho.client.mqttv3.MqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.MqttTopic;

  public class MQTTSubscriber2 {


static final String BROKER_URL = "tcp://localhost:1883";// public
// mosquitto server
static final String TOPIC = "iotm/stream1"; 



public static void main(String args[]) {

    try {
        // Creating new default persistence for mqtt client
        MqttDefaultFilePersistence persistence = new MqttDefaultFilePersistence(
                "/tmp");

        // mqtt client with specific url and a random client id
        MqttClient client = new MqttClient(BROKER_URL, "Subscriber-ID",
                persistence);
        client.connect();
        System.out.println("Subscribing to topic '" + TOPIC + "' from "
                + client.getServerURI());
        // Subscribing to specific topic
        client.subscribe(TOPIC);

        // It will trigger when a new message is arrived
        MqttCallback callback = new MqttCallback() {
            @Override
            public void messageArrived(MqttTopic arg0, MqttMessage arg1)
                    throws Exception {
                System.out.println("Message:"
                        + new String(arg1.getPayload()));

            }

            @Override
            public void deliveryComplete(MqttDeliveryToken arg0) {

            }

            @Override
            public void connectionLost(Throwable arg0) {
                System.out.println("Connection lost");
            }
        };
        // Continue waiting for messages until the Enter is pressed
        client.setCallback(callback);
        /*
         * System.out.println("Press <Enter> to exit"); try {
         * System.in.read(); } catch (IOException e) { // If we can't read
         * we'll just exit }
         */
        // client.disconnect();
        // System.out.println("Client Disconnected");

    } catch (MqttException e) {
        e.printStackTrace();
    } catch (Exception e) {
        System.err.println(e.getMessage());
    }
}

import org.eclipse.paho.client.mqttv3.MqttCallback；
导入org.eclipse.paho.client.mqttv3.MqttClient；
导入org.eclipse.paho.client.mqttv3.MqttDefaultFilePersistence；
导入org.eclipse.paho.client.mqttv3.MqttDeliveryToken；
导入org.eclipse.paho.client.mqttv3.MqttException；
导入org.eclipse.paho.client.mqttv3.MqttMessage；
导入org.eclipse.paho.client.mqttv3.MqttTopic；
公共类MQTTSubscriber2{
静态最终字符串BROKER_URL=”tcp://localhost:1883“；//公开
//MOSQUITO服务器
静态最终字符串TOPIC=“iotm/stream1”；
公共静态void main（字符串参数[]）{
试一试{
//为mqtt客户机创建新的默认持久性
MqttDefaultFilePersistence persistence=新MqttDefaultFilePersistence(
“/tmp”）；
//具有特定url和随机客户端id的mqtt客户端
MqttClient=新MqttClient（代理URL，“订户ID”，
持久性）；
client.connect（）；
System.out.println（“订阅主题”’+topic+“'from”
+client.getServerURI（））；
//订阅特定主题
client.subscribe（主题）；
//它将在新消息到达时触发
MqttCallback callback=新的MqttCallback（）{
@凌驾
public void messageArrived（MqttTopic arg0、MqttMessage arg1）
抛出异常{
System.out.println（“消息：
+新字符串（arg1.getPayload（））；
}
@凌驾
公共无效交付完成（MqttDeliveryToken arg0）{
}
@凌驾
public void connectionLost（可丢弃arg0）{
System.out.println（“连接丢失”）；
}
};
//继续等待消息，直到按Enter键
client.setCallback（callback）；
/*
*System.out.println（“按下退出”）；尝试{
*System.in.read（）；}catch（IOException e）{//如果我们无法读取
*我们就退出}
*/
//client.disconnect（）；
//System.out.println（“客户端断开”）；
}捕获（MqttException e）{
e、 printStackTrace（）；
}捕获（例外e）{
System.err.println（e.getMessage（））；
}
}

---

}

如果您运行的是两个单独的订阅服务器代码实例，则它们都需要不同的客户端ID。如果使用同一个代理运行2，则当第二个代理连接时，第一个代理将断开与代理的连接。

能否发布一些示例代码来说明问题？也不清楚，但是您使用的是2个客户端实例吗？如果是这样，他们将需要不同的客户ids@hardillb：添加了我的示例代码。。实际上，我是mqtt新手，所以我只是根据net中的一个示例来做这件事