Activemq獲取消費者數量(consumerCount)

最近開始學習activemq系統的使用，關於如何在activemq中時實獲取一個主題/隊列(topic/queue)的訂閱/消費者數量，讓我花了挺多時間才搞明白:
在activemq中，可以通過訂閱主題或隊列對應的消息管理主題,從而獲取諮詢消息(Advisory Message),
每當新增/減少訂閱者時都會收到相關的諮詢消息。
Advisory Message中就包含了一些我們想要的數據(包含在consumerCount屬性中)。
關於Advisory Message的詳細說明參見官方文檔： http://activemq.apache.org/advisory-message.html

廢話少說，上代碼，下面的代碼完整說明了如何從Advisory Message獲取consumerCount屬性得到消費者數量.
以下爲JUNIT 測試代碼：

import javax.jms.Connection;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageListener;
import javax.jms.Session;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.advisory.AdvisorySupport;
import org.apache.activemq.command.ActiveMQTopic;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class TestAdvisory {
	private static final Logger logger = LoggerFactory.getLogger(TestAdvisory.class);

	@Test
	public void test() {
		// 創建連接本地activemq的ActiveMQConnectionFactory實例
		ActiveMQConnectionFactory connectionFactory = new ActiveMQConnectionFactory();
		Connection connection = null;
		try {
			connection = connectionFactory.createConnection();
			connection.start();
			Session session = connection.createSession(Boolean.FALSE, Session.AUTO_ACKNOWLEDGE);
			// 創建 advisory topic : ActiveMQ.Advisory.Consumer.Topic.chat1,用於監控topic消費者的狀態變化
			ActiveMQTopic advisoryTopic = AdvisorySupport.getConsumerAdvisoryTopic(new ActiveMQTopic("chat1"));
			MessageConsumer consumer = session.createConsumer(advisoryTopic);
			consumer.setMessageListener(new MessageListener() {
				@Override
				public void onMessage(Message message) {
					try {
						// 獲取消費者數量屬性
						int consumerCount = message.getIntProperty("consumerCount");
						logger.info("consumerCount = {} ",consumerCount);
					} catch (JMSException e) {
						e.printStackTrace();
					}
				}
			});
			Thread.sleep(20000);
		} catch (Exception e) {
			e.printStackTrace();
		}finally {
			try {
				if(null != connection){
					connection.close();
				}
			} catch (JMSException e) {
				e.printStackTrace();
			}
		}
	}

}