我正在使用RabbitMQ MQTT适配器和Paho MQTT客户端。
RabbitMQ版本：{rabbitmq_mqtt,"RabbitMQ MQTT Adapter","3.2.1"}
Paho MQTT客户端版本：
<dependency>
<groupId>org.eclipse.paho</groupId>
<artifactId>org.eclipse.paho.client.mqttv3</artifactId>
<version>RELEASE</version>
</dependency>
请参阅内联代码。
我试图了解订阅者队列是否可以持久而没有到期时间。如果消息也可以持久。 正如我从RabbitMQ文档中所理解的，每次订阅者订阅主题时 RabbitMQ将使用以下命名约定创建一个队列：
mqtt-subscription-<ClientName>qos<ClientQOS>
此队列有一个到期时间，如何创建没有到期时间的队列？我可以将此队列到期时间更改为无限时间吗？
至于现在我每次运行这个命令：“service rabbitmq-server restart”
队列中的消息被删除。
我该怎样防止这种情况？有没有办法可以在重启后将消息保留在队列中？
在RabbitMQ管理界面中，我可以在“发布消息”下看到 - ＆gt; “交付模式：”可以是“2持久”。 如果我使用管理UI发布传递模式= 2-persistent的消息。服务重启后，消息将在队列中。
如何使用Paho MQTT Client实现相同目标？
// Heavily based on RabbitMQ MQTT adapter test case code!
// first, import the RabbitMQ Java client
// and the Paho MQTT client classes, plus any other
// requirements
import com.rabbitmq.client.*;
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.MqttDeliveryToken;
import org.eclipse.paho.client.mqttv3.MqttException;
import org.eclipse.paho.client.mqttv3.MqttMessage;
import org.eclipse.paho.client.mqttv3.MqttTopic;
import org.eclipse.paho.client.mqttv3.internal.NetworkModule;
import org.eclipse.paho.client.mqttv3.internal.TCPNetworkModule;
// import org.eclipse.paho.client.mqttv3.internal.trace.Trace;
import org.eclipse.paho.client.mqttv3.internal.wire.MqttOutputStream;
import org.eclipse.paho.client.mqttv3.internal.wire.MqttPublish;
import javax.net.SocketFactory;
import java.io.IOException;
import java.net.InetAddress;
import java.net.Socket;
import java.util.*;
/***
* MQTT v3.1 tests
* TODO: synchronise access to variables
*/
public class MqttTestClean implements MqttCallback {
// setup some variables which define where the MQTT broker is
private final String host = "0.0.0.0";
private final int port = 1883;
private final String brokerUrl = "tcp://" + host + ":" + port;
private String clientId;
private String clientId3;
private MqttClient client;
private MqttClient client3;
private MqttConnectOptions conOpt;
private ArrayList<MqttMessage> receivedMessages;
// specify a message payload - doesn't matter what this says, but since MQTT expects a byte array
// we convert it from string to byte array here
private final byte[] payload = "This payload was published on MQTT and read using AMQP.".getBytes();
// specify the topic to be used
private final String topic = "topic/proxy/1.0.0/Report/*";
private int testDelay = 2000;
private long lastReceipt;
private boolean expectConnectionFailure;
private ConnectionFactory connectionFactory;
private Connection conn;
private Channel ch;
// override 10s limit
private class MyConnOpts extends MqttConnectOptions {
private int keepAliveInterval = 60;
@Override
public void setKeepAliveInterval(int keepAliveInterval) {
this.keepAliveInterval = keepAliveInterval;
}
@Override
public int getKeepAliveInterval() {
return keepAliveInterval;
}
}
public void setUpMqtt() throws MqttException {
clientId = getClass().getSimpleName() + ((int) (10000*Math.random()));
client = new MqttClient(brokerUrl, clientId);
conOpt = new MyConnOpts();
setConOpts(conOpt);
receivedMessages = new ArrayList<MqttMessage>();
expectConnectionFailure = false;
}
public void tearDownMqtt() throws MqttException {
try {
client.disconnect();
} catch (Exception _) {}
}
private void setUpAmqp() throws Exception {
connectionFactory = new ConnectionFactory();
connectionFactory.setHost(host);
conn = connectionFactory.newConnection();
ch = conn.createChannel();
}
private void tearDownAmqp() throws IOException {
conn.close();
}
private void setConOpts(MqttConnectOptions conOpts) {
conOpts.setCleanSession(true);
conOpts.setKeepAliveInterval(60);
}
private void publish(MqttClient client, String topicName, int qos, byte[] payload) throws MqttException {
MqttTopic topic = client.getTopic(topicName);
MqttMessage message = new MqttMessage(payload);
message.setQos(qos);
MqttDeliveryToken token = topic.publish(message);
token.waitForCompletion();
}
public void connectionLost(Throwable cause) {
if (!expectConnectionFailure)
System.out.println("Connection unexpectedly lost");
}
public void messageArrived(String topic, MqttMessage message) throws Exception {
lastReceipt = System.currentTimeMillis();
System.out.println("-------------------------------------------------");
System.out.println("------------------" + lastReceipt + "-------------------------------");
System.out.println("------------------" + message.toString() + "-------------------------------");
receivedMessages.add(message);
}
public void deliveryComplete(IMqttDeliveryToken token) {
}
public void run() {
try {
setUpMqtt(); // initialise the MQTT connection
setUpAmqp(); // initialise the AMQP connection
connect();
//String queue = ch.queueDeclare().getQueue();
// String queue = ch.queueDeclare("mqtt-subscription-Snabel-3qos1", true, false, false, null).getQueue();
//ch.queueBind(queue, "amq.topic", "sci-topic.sc.proxy_1393.1.0.0.ApReport.*"/*topic*/);
client.connect(conOpt);
publish(client, "topic/proxy/1.0.0/Report/123456789",1, payload); // publish the MQTT message
client.disconnect();
Thread.sleep(testDelay);
tearDownAmqp(); // cleanup AMQP resources
tearDownMqtt(); // cleanup MQTT resources*/
disConnect();
} catch (Exception mqe) {
mqe.printStackTrace();
}
}
private void connect() throws Exception {
clientId3 = "Test-3";
client3 = new MqttClient(brokerUrl, clientId3);
MqttConnectOptions connOpts = new MqttConnectOptions();
connOpts.setCleanSession(false);
client3.connect(connOpts);
client3.setCallback(this);
client3.subscribe(topic);
if(!client3.isConnected()){
System.out.println("Not Connected");
return;
}
System.out.println("Connected");
}
private void disConnect() throws Exception {
try {
client3.disconnect();
} catch (Exception _) {}
}
public static void main(String[] args) {
MqttTest mqt = new MqttTest();
mqt.run();
}
}
答案 0 :(得分：0)