我一直在寻找一些文档/示例来检查动态创建的主题是否存在,如果存在,如何获取该主题的订阅者计数。
我使用以下代码向主题发送消息 -
jmsTemplate.send(destination, new MessageCreator() {
@Override
public Message createMessage(Session session) throws JMSException {
TextMessage message = session.createTextMessage();
message.setText(commandStr);
return message;
}
});
这段代码似乎创建了主题并向主题发布消息。
- 我需要在创建主题之前检查该主题是否存在。
- 检查该主题是否有订阅者。
提前致谢
我能够找到(1)问题的解决方案(希望这有帮助)-
ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");
ActiveMQConnection connection = (ActiveMQConnection)connectionFactory.createConnection();
connection.start();
DestinationSource ds = connection.getDestinationSource();
Set<ActiveMQTopic> topics = ds.getTopics();
最佳答案
要获取目的地名称,正如您所做的那样,它是正确的,您可以通过 JMX 来专门获取订阅者计数等统计信息...
import java.util.HashMap;
import java.util.Map;
import javax.management.MBeanServerConnection;
import javax.management.MBeanServerInvocationHandler;
import javax.management.ObjectName;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;
import org.apache.activemq.broker.jmx.BrokerViewMBean;
import org.apache.activemq.broker.jmx.TopicViewMBean;
public class JMXGetDestinationInfos {
public static void main(String[] args) throws Exception {
JMXServiceURL url = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://localhost:1099/jmxrmi");
Map<String, String[]> env = new HashMap<>();
String[] creds = { "admin", "admin" };
env.put(JMXConnector.CREDENTIALS, creds);
JMXConnector jmxc = JMXConnectorFactory.connect(url, env);
MBeanServerConnection conn = jmxc.getMBeanServerConnection();
ObjectName activeMq = new ObjectName("org.apache.activemq:type=Broker,brokerName=localhost");
BrokerViewMBean mbean = MBeanServerInvocationHandler.newProxyInstance(conn, activeMq, BrokerViewMBean.class,
true);
for (ObjectName name : mbean.getTopics()) {
if (("YOUR_TOPIC_NAME".equals(name.getKeyProperty("destinationName")))) {
TopicViewMBean topicMbean = MBeanServerInvocationHandler.newProxyInstance(conn, name,
TopicViewMBean.class, true);
System.out.println(topicMbean.getConsumerCount());
}
}
}
}
或
import java.util.Set;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.advisory.DestinationSource;
import org.apache.activemq.command.ActiveMQQueue;
import org.apache.activemq.command.ActiveMQTopic;
public class AdvisorySupportGetAllDestinationsNames {
public static void main(String[] args) throws JMSException {
Connection conn = null;
try {
ConnectionFactory cf = new ActiveMQConnectionFactory("tcp://localhost:61616");
conn = cf.createConnection();
conn.start();
DestinationSource destinationSource = ((ActiveMQConnection) conn).getDestinationSource();
Set<ActiveMQQueue> queues = destinationSource.getQueues();
Set<ActiveMQTopic> topics = destinationSource.getTopics();
System.out.println(queues);
System.out.println(topics);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (conn != null) {
try {
conn.close();
} catch (Exception e) {
}
}
}
}
}
更新
您可以使用AdvisorySupport.getConsumerAdvisoryTopic()
Note that the consumer start/stop advisory messages also have a consumerCount header to indicate the number of active consumers on the destination when the advisory message was sent.
关于java - JMSTemplate 检查主题是否存在并获取订阅者数量,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/44707064/