在ActiveMQ Artemis中,当使用带有通配符的队列时,如果消费者取消其与队列的订阅,或者在队列上执行其他操作,例如重新命名队列,则该队列中所有未处理的消息将被重新分配到新的队列中。在这种情况下,有时可能需要更改消息的目标地,例如进行额外的处理或修改消息内容。 下面是一个示例代码,演示如何通过设置拦截器来更改消息的目的地:
import javax.jms.*;
import org.apache.activemq.artemis.api.core.*;
import org.apache.activemq.artemis.api.core.client.*;
import org.apache.activemq.artemis.api.core.client.ClientConsumer;
import org.apache.activemq.artemis.api.core.client.ClientMessage;
import org.apache.activemq.artemis.api.core.client.ClientProducer;
import org.apache.activemq.artemis.api.core.client.ClientSession;
public class MessageRedistributionExample {
public static void main(final String[] args) throws Exception {
Connection connection = null;
Session session = null;
try {
ConnectionFactory connectionFactory = new org.apache.activemq.ActiveMQConnectionFactory("tcp://localhost:61616");
connection = connectionFactory.createConnection("admin", "admin");
connection.start();
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
Queue queue = session.createQueue("queue.#");
MessageConsumer consumer = session.createConsumer(queue);
MessageProducer producer = session.createProducer(null);
consumer.setMessageListener(new MessageListener() {
public void onMessage(Message message) {
if (message instanceof ActiveMQMessage) {
ActiveMQMessage amqMessage = (ActiveMQMessage)message;
SimpleString destination = amqMessage.getSimpleStringProperty("originalDestination");
if (destination != null && !destination.toString().equals(amqMessage.getAddress())) {
try {
amqMessage.setAddress(destination.toString());
producer.send(destination.toString(), amqMessage);
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
});
Thread.sleep(1000000);
} finally {
if (session != null) {
session.close();
}
if (connection != null) {
connection.close();
}
}
}
}
在上面的示例代码中,我们创建了一个'queue.#”队列,并使用消息监听器来拦截传入的消息。如果消息是ActiveMQMessage类型,我们将检查消息的原始目的地