如果您想要在ActiveMQ上使用onMessage方法，并使用createDurableSubscriber创建一个持久化的订阅者，则需要向ConnectionFactory添加一个uniqueClientId。这个uniqueClientId将使持久化检查点保存在ActiveMQ中，并将在下一次您启动应用程序时自动恢复。以下是一个使用uniqueClientId的Java示例代码：

public class Consumer implements MessageListener {

  public static void main(String[] args) {
    ConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");
    Connection connection = null;
    try {
        connection = connectionFactory.createConnection();
        connection.setClientID("UniqueClientId");
        connection.start();

        Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
        Topic myTopic = session.createTopic("MyTopic");
        MessageConsumer consumer = session.createDurableSubscriber(myTopic, "mySubscriptionName");
        consumer.setMessageListener(new Consumer());
    } catch (JMSException e) {
        e.printStackTrace();
    }
  }

  public void onMessage(Message message) {
      // process received message
  }
}