Java ActiveMQ+;MQTT+;订阅;ActiveMQ.Advisory.Connection“;
这就是背景: Java应用程序通过MQTT(Paho 0.4.0)从ActiveMQ 5.9.1订阅主题“ActiveMQ.Advisory.Connection”: 与ActiveMQ的连接建立良好。本主题提供有关ActiveMQ中的连接(打开/关闭)的信息,但我的问题是我捕获的消息是空的: MQTT Mesage到达[ActiveMQ/Advisory/Connection]Msg[] 是否有任何方法可以使用MQTT捕获它们?或者我应该使用JMS来实现这一点 谢谢,Java ActiveMQ+;MQTT+;订阅;ActiveMQ.Advisory.Connection“;,java,jms,activemq,mqtt,paho,Java,Jms,Activemq,Mqtt,Paho,这就是背景: Java应用程序通过MQTT(Paho 0.4.0)从ActiveMQ 5.9.1订阅主题“ActiveMQ.Advisory.Connection”: 与ActiveMQ的连接建立良好。本主题提供有关ActiveMQ中的连接(打开/关闭)的信息,但我的问题是我捕获的消息是空的: MQTT Mesage到达[ActiveMQ/Advisory/Connection]Msg[] 是否有任何方法可以使用MQTT捕获它们?或者我应该使用JMS来实现这一点 谢谢, Jon Ander。问题
Jon Ander。问题是您希望MQTT客户机在作为消息主体的咨询主题上收到什么。通知通常包括许多信息作为消息属性,但是这些信息不能映射到MQTT,因为MQTT消息没有属性。连接通知的正文是用于创建连接的ConnectionInfo对象的副本。在MQTT方面,您对此无能为力,因为您将接收到的只是该对象的序列化字节,而您无法对其执行任何操作 谢谢你,蒂姆。如果ActiveMQ能够使用JSON等标准格式共享连接信息,那就太好了。您可以打开一个增强请求,让负载对象以XML或JSON的形式发送,类似于STOMP客户端的工作方式。因为没有消息头,所以无法向客户机指示内容类型,客户机必须支持默认情况下发送的任何内容。
public class SupervisorMqttClient implements MqttCallback {
private MqttClient client = null;
private MemoryPersistence persistence = null;
private MqttConnectOptions connOpts = null;
private final int STATUS_OK = 0;
private final int STATUS_ERROR = 1;
private String mqttServer = null;
private String clientId = null;
private int status = STATUS_OK;
public SupervisorMqttClient() {
try {
this.init();
} catch (MqttException e) {
Logger.error(e.getLocalizedMessage());
Logger.debug(e);
}
}
private void init() throws MqttException {
Properties props = PropertiesManager.getInstance("supervisor");
mqttServer = props.getProperty("supervisor.mqtt.server");
String supervisorID = props.getProperty("supervisor.mqtt.client.number");
clientId = Supervisor.APP_NAME+"-"+supervisorID;
connOpts = new MqttConnectOptions();
connOpts.setKeepAliveInterval(30);
connOpts.setCleanSession(true); // important non-durable
persistence = new MemoryPersistence();
client = new MqttClient(mqttServer, clientId, persistence);
connectAndSubscribe();
}
private void connectAndSubscribe() throws MqttSecurityException, MqttException {
try {
client.connect(connOpts);
client.setCallback(this);
client.subscribe("ActiveMQ/Advisory/Connection");
} catch (MqttSecurityException e) {
Logger.error(e.getLocalizedMessage());
Logger.debug(e);
} catch (MqttException e) {
Logger.error(e.getLocalizedMessage());
Logger.debug(e);
processError(e);
}
}
public void publish(String orderType, JSONObject jsonExtraData) {
if (status == STATUS_ERROR) {
connectAndSubscribe();
}
if (status == STATUS_OK) {
// some code here
}
}
@Override
public void connectionLost(Throwable err) {
Logger.info("Connection lost");
}
@Override
public void deliveryComplete(IMqttDeliveryToken arg0) {
Logger.info("deliveryComplete");
}
@Override
public void messageArrived(String topic, MqttMessage msg) throws Exception {
System.out.println("MQTT Mesage Arrived[" + topic + "] Msg[" + msg.toString() + "]");
}
private void processError(MqttException e) {
status = STATUS_ERROR;
try {
if (client.isConnected()) {
Logger.error("disconnecting");
client.disconnect();
}
} catch (MqttException ex) {
Logger.error(ex.getLocalizedMessage());
Logger.debug(ex);
}
}
}