10

如何在 java (JRE /JDK / J2EE 1.4) 中实例化只接收与给定 JMSCorrelationID 匹配的消息的 JMS 队列侦听器？我要获取的消息已发布到队列而不是主题，尽管如果需要可以更改。

这是我目前用来将消息放入队列的代码：

/**
 * publishResponseToQueue publishes Requests to the Queue.
 *
 * @param   jmsQueueFactory             -Name of the queue-connection-factory
 * @param   jmsQueue                    -The queue name for the request
 * @param   response                     -A response object that needs to be published
 * 
 * @throws  ServiceLocatorException     -An exception if a request message
 *                                      could not be published to the Topic
 */
private void publishResponseToQueue( String jmsQueueFactory,
                                    String jmsQueue,
                                    Response response )
        throws ServiceLocatorException {

    if ( logger.isInfoEnabled() ) {
        logger.info( "Begin publishRequestToQueue: " +
                         jmsQueueFactory + "," + jmsQueue + "," + response );
    }
    logger.assertLog( jmsQueue != null && !jmsQueue.equals(""),
                      "jmsQueue cannot be null" );
    logger.assertLog( jmsQueueFactory != null && !jmsQueueFactory.equals(""),
                      "jmsQueueFactory cannot be null" );
    logger.assertLog( response != null, "Request cannot be null" );

    try {

        Queue queue = (Queue)_context.lookup( jmsQueue );

        QueueConnectionFactory factory = (QueueConnectionFactory)
            _context.lookup( jmsQueueFactory );

        QueueConnection connection = factory.createQueueConnection();
        connection.start();
        QueueSession session = connection.createQueueSession( false,
                                    QueueSession.AUTO_ACKNOWLEDGE );

        ObjectMessage objectMessage = session.createObjectMessage();

        objectMessage.setJMSCorrelationID(response.getID());

        objectMessage.setObject( response );

        session.createSender( queue ).send( objectMessage );

        session.close();
        connection.close();

    } catch ( Exception e ) {
        //XC3.2  Added/Modified BEGIN
        logger.error( "ServiceLocator.publishResponseToQueue - Could not publish the " +
                      "Response to the Queue - " + e.getMessage() );
        throw new ServiceLocatorException( "ServiceLocator.publishResponseToQueue " +
                                           "- Could not publish the " +
                      "Response to the Queue - " + e.getMessage() );
        //XC3.2  Added/Modified END
    }

    if ( logger.isInfoEnabled() ) {
        logger.info( "End publishResponseToQueue: " +
                         jmsQueueFactory + "," + jmsQueue + response );
    }

}  // end of publishResponseToQueue method
4

4 回答 4

11

队列连接设置是相同的，但是一旦有了 QueueSession，就可以在创建接收器时设置选择器。

    QueueReceiver receiver = session.createReceiver(myQueue, "JMSCorrelationID='theid'");

然后

receiver.receive()

或者

receiver.setListener(myListener);
于 2008-09-29T15:25:14.443 回答
5

顺便说一句，虽然这不是您提出的实际问题 - 如果您尝试通过 JMS 实现请求响应，我建议您阅读这篇文章，因为 JMS API 比您想象的要复杂得多，并且有效地做到这一点比它困难得多看起来。

特别是为了有效地使用 JMS，您应该尽量避免为单个消息等创建消费者。

此外，由于 JMS API 非常复杂，无法正确有效地使用——尤其是在池、事务和并发处理方面——我建议人们将中间件从他们的应用程序代码中隐藏起来，例如通过使用Apache Camel 的 JMS 的 Spring Remoting 实现

于 2008-09-29T16:10:32.227 回答
2

希望这会有所帮助。我使用了 Open MQ。

package com.MQueues;

import java.util.UUID;

import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.QueueConnection;
import javax.jms.QueueReceiver;
import javax.jms.QueueSession;
import javax.jms.Session;
import javax.jms.TextMessage;

import com.sun.messaging.BasicQueue;
import com.sun.messaging.QueueConnectionFactory;

public class HelloProducerConsumer {

public static String queueName = "queue0";
public static String correlationId;

public static String getCorrelationId() {
    return correlationId;
}

public static void setCorrelationId(String correlationId) {
    HelloProducerConsumer.correlationId = correlationId;
}

public static String getQueueName() {
    return queueName;
}

public static void sendMessage(String threadName) {
    correlationId = UUID.randomUUID().toString();
    try {

        // Start connection
        QueueConnectionFactory cf = new QueueConnectionFactory();
        QueueConnection connection = cf.createQueueConnection();
        QueueSession session = connection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
        BasicQueue destination = (BasicQueue) session.createQueue(threadName);
        MessageProducer producer = session.createProducer(destination);
        connection.start();

        // create message to send
        TextMessage message = session.createTextMessage();
        message.setJMSCorrelationID(correlationId);
        message.setText(threadName + "(" + System.currentTimeMillis() 
                + ") " + correlationId +" from Producer");

        System.out.println(correlationId +" Send from Producer");
        producer.send(message);

        // close everything
        producer.close();
        session.close();
        connection.close();

    } catch (JMSException ex) {
        System.out.println("Error = " + ex.getMessage());
    }
}

public static void receivemessage(final String correlationId) {
    try {

        QueueConnectionFactory cf = new QueueConnectionFactory();
        QueueConnection connection = cf.createQueueConnection();
        QueueSession session = connection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);

        BasicQueue destination = (BasicQueue) session.createQueue(getQueueName());

        connection.start();

        System.out.println("\n");
        System.out.println("Start listen " + getQueueName() + " " + correlationId +" Queue from receivemessage");
        long now = System.currentTimeMillis();

        // receive our message
        String filter = "JMSCorrelationID = '" + correlationId  + "'";
        QueueReceiver receiver = session.createReceiver(destination, filter);
        TextMessage m = (TextMessage) receiver.receive();
        System.out.println("Received message = " + m.getText() + " timestamp=" + m.getJMSTimestamp());

        System.out.println("End listen " + getQueueName() + " " + correlationId +" Queue from receivemessage");

        session.close();
        connection.close();

    } catch (JMSException ex) {
        System.out.println("Error = " + ex.getMessage());
    }
}

public static void main(String args[]) {
    HelloProducerConsumer.sendMessage(getQueueName());
    String correlationId1 = getCorrelationId();
    HelloProducerConsumer.sendMessage(getQueueName());
    String correlationId2 = getCorrelationId();
    HelloProducerConsumer.sendMessage(getQueueName());
    String correlationId3 = getCorrelationId();


    HelloProducerConsumer.receivemessage(correlationId2);

    HelloProducerConsumer.receivemessage(correlationId1);

    HelloProducerConsumer.receivemessage(correlationId3);
}
}
于 2015-01-06T18:51:40.373 回答
0 
String filter = "JMSCorrelationID = '" + msg.getJMSMessageID() + "'";
QueueReceiver receiver = session.createReceiver(queue, filter);

在这里，接收者将获得JMSCorrelationID等于的消息MessageID。这在请求/响应范例中非常有帮助。

或者您可以直接将其设置为任何值：

QueueReceiver receiver = session.createReceiver(queue,  "JMSCorrelationID ='"+id+"'";);

比你可以做的receiver.receive(2000);或者receiver.setMessageListener(this);

于 2013-10-21T22:19:07.650 回答