AsyncRabbitTemplate 中的回复消息后处理

Question

我在使用 AsyncRabbitTemplate 时遇到了 GZip/GUnzip 消息处理问题。

使用这样的同步模板设置一切正常：

@Bean
@Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
public RabbitTemplate rabbitTemplate(final ConnectionFactory connectionFactory) {
    final RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
    rabbitTemplate.setMessageConverter(jsonConverter());
    rabbitTemplate.setReplyTimeout(config.getRabbitSendAndReceiveReplyTimeout());
    rabbitTemplate.setReceiveTimeout(config.getRabbitSendAndReceiveReceiveTimeout());
    rabbitTemplate.setAfterReceivePostProcessors(new GUnzipPostProcessor(true));
    rabbitTemplate.setBeforePublishPostProcessors(new GZipPostProcessor(true));
    return rabbitTemplate;
}

但是，当我像这样设置异步模板时：

@Bean
@Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
public AsyncRabbitTemplate rabbitTemplateAsync(final ConnectionFactory connectionFactory) {
    final AsyncRabbitTemplate asyncRabbitTemplate = new AsyncRabbitTemplate(rabbitTemplate(connectionFactory));
    // need to manually start the reply listener container for some reason
    asyncRabbitTemplate.start();
    return asyncRabbitTemplate;
}

回复消息未正确解压缩，我收到此错误消息

Caused by: java.io.UnsupportedEncodingException: gzip:UTF-8
    at java.lang.StringCoding.decode(Unknown Source) ~[?:1.8.0_192]
    at java.lang.String.<init>(Unknown Source) ~[?:1.8.0_192]
    at java.lang.String.<init>(Unknown Source) ~[?:1.8.0_192]
    at org.springframework.amqp.support.converter.AbstractJackson2MessageConverter.convertBytesToObject(AbstractJackson2MessageConverter.java:235) ~[spring-amqp-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.amqp.support.converter.AbstractJackson2MessageConverter.fromMessage(AbstractJackson2MessageConverter.java:199) ~[spring-amqp-2.1.4.RELEASE.jar:2.1.4.RELEASE]
    at org.springframework.amqp.rabbit.AsyncRabbitTemplate.onMessage(AsyncRabbitTemplate.java:576) ~[spring-rabbit-2.1.4.RELEASE.jar:2.1.4.RELEASE]

我尝试为 AsyncRabbitTemplate 提供一个已配置的 DirectReplyToMessageListenerContainer，但没有帮助

    final DirectReplyToMessageListenerContainer directReplyToMessageListenerContainer = new DirectReplyToMessageListenerContainer(
            connectionFactory);
    directReplyToMessageListenerContainer.setAfterReceivePostProcessors(new GUnzipPostProcessor(true));
    final AsyncRabbitTemplate asyncRabbitTemplate = new AsyncRabbitTemplate(rabbitTemplate(connectionFactory),
            directReplyToMessageListenerContainer);

这只会导致这个错误：

[错误] 2019-03-06 12:18:05.192 [AMQP 连接 172.17.3.6:5672] CachingConnectionFactory.log - 通道关闭：通道错误；协议方法：#method(reply-code=406, reply-text=PRECONDITION_FAILED - 快速回复消费者不存在, class-id=60, method-id=40)

请注意，我可以通过使用 spring-rabbit 项目的一个分支并将此构造函数添加到 AsyncRabbitTemplate 来使事情正常进行：

public IndigoAsyncRabbitTemplate(final RabbitTemplate template,
        final DirectReplyToMessageListenerContainer directReplyToContainer) {
    Assert.notNull(template, "'template' cannot be null");
    this.template = template;
    container = null;
    replyAddress = null;
    this.directReplyToContainer = directReplyToContainer;
    directReplyToContainer.setMessageListener(this);
}

那么，这是否需要对 spring rabbit 库进行增强才能开始工作？或者有没有办法让 GUnzip 在回复侦听器上工作而不会跳过太多的环节？

Answer 1

是的，这必须作为对框架的改进。在AsyncRabbitTemplate 的情况下，我们只是错过了afterReceivePostProcessors 的事实。我们可以从提供的RabbitTemplate 重新配置一个内部DirectReplyToMessageListenerContainer 以使用afterReceivePostProcessors。

同时，您可以坚持使用常规的SimpleMessageListenerContainer 注入。 或者您可以尝试使用外部DirectReplyToMessageListenerContainer 注入。

看到这个演员：

/**
 * Construct an instance using the provided arguments. The first queue the container
 * is configured to listen to will be used as the reply queue. Replies will be
 * routed using the default exchange with that queue name as the routing key.
 * @param template a {@link RabbitTemplate}
 * @param container a {@link AbstractMessageListenerContainer}.
 */
public AsyncRabbitTemplate(RabbitTemplate template, AbstractMessageListenerContainer container) {
    this(template, container, null);
}

关于此事的问题：https://github.com/spring-projects/spring-amqp/issues/920