如何用JmsTemplate设置replyTo？

Question

我让一个消费者消费一条消息，进行一些转换，然后创建一个新的Pojo并将其传递给生产者。生产者使用JmsTemplate在队列中发送消息。生产者应该将原始消息的头部(如(JMSType，JMSCorrelationID，JMSExpiration，JMSDeliveryMode) )设置为要发送的新消息。但是生产者应该更改原始消息的replyTo目的地。我还没有找到创建目的地并设置为JMSReplyTo的方法。有些人知道我如何做到这一点？

也许JmsTemplate不是做这件事的正确类。

public class Producer {

    private final JmsTemplate jmsTemplate;

    @Value("${jms-destination}")
    private String destination;

    public Producer(@Autowired JmsTemplate jmsTemplate) {
        this.jmsTemplate = jmsTemplate;
    }

    public void send(final MessageHeaders headers, final Pojo pojo) {
        Validate.notNull(order);

        jmsTemplate.convertAndSend(destination, pojo, (message) -> {
          final Destination replyToDestination = ???;
          message.setJMSReplyTo(replyToDestination);

          message.setJMSType((String) headers.get(JmsHeaders.TYPE));
          message.setJMSCorrelationID((String) headers.get(JmsHeaders.CORRELATION_ID));
          message.setJMSExpiration((long) headers.get(JmsHeaders.EXPIRATION));
          message.setJMSDeliveryMode((int) headers.get(JmsHeaders.DELIVERY_MODE));
          return message;
      });

    }
}

我发现只有这种方法可以做到，但我不喜欢也不确定这会带来副作用：

public class Producer {

    private final JmsTemplate jmsTemplate;

    @Value("${jms-destination}")
    private String destination;

    @Value("${jms-replyTo}")
    private String replyTo;

    public Producer(@Autowired JmsTemplate jmsTemplate) {
        this.jmsTemplate = jmsTemplate;
    }

    public void send(final MessageHeaders headers, Pojo pojo) {
        Validate.notNull(order);

        jmsTemplate.convertAndSend(destination, order, (message) -> {
          final Destination replyToDestination = buildReplyTo();
          message.setJMSReplyTo(replyToDestination);

          message.setJMSType((String) headers.get(JmsHeaders.TYPE));
          message.setJMSCorrelationID((String) headers.get(JmsHeaders.CORRELATION_ID));
          message.setJMSExpiration((long) headers.get(JmsHeaders.EXPIRATION));
          message.setJMSDeliveryMode((int) headers.get(JmsHeaders.DELIVERY_MODE));
          return message;
      });

    }

    private Destination buildReplyTo() throws JMSException {
      final Session session = jmsTemplate.getConnectionFactory().createConnection()
          .createSession(false, Session.AUTO_ACKNOWLEDGE);
      final Destination queue =
          jmsTemplate.getDestinationResolver().resolveDestinationName(session, replyTo, false);
      return queue;
    }

}

Answer 1

您的解决方案创建了不闭合的侧向连接。您应该使用已有的session对象，通过send API手动发送您的pojo。使用getRequiredMessageConverter转换您的pojo。

public void send(final MessageHeaders headers, Pojo pojo) {
    Validate.notNull(order);

    final String responseQueue = "responseQ";
    jmsTemplate.send(destination,
            session -> {
                Message message = getRequiredMessageConverter().toMessage(message, session);
                message.setJMSReplyTo(session.createQueue(responseQueue)); //fill queue

                //any other setters             
                return message;
            });         
}

// based on Spring JmsTemplate library
private MessageConverter getRequiredMessageConverter() throws IllegalStateException {
    MessageConverter converter = jmsTemplate.getMessageConverter();
    if (converter == null) {
        throw new IllegalStateException("No 'messageConverter' specified. Check configuration of JmsTemplate.");
    } else {
        return converter;
    }
}