SimpleRabbitListenerContainerFactory 和 defaultRequeueRejected

Question

根据文档，defaultRequeueRejected 的默认值为 true，但查看代码似乎是 false。我不确定我是否遗漏了什么，或者我们必须在 SimpleRabbitListenerContainerFactory.java 中更改它

编辑

示例代码，将消息放入测试队列后，我希望它在失败后保持在队列中，但它正在将其抛出。我想重试消息，所以我在容器工厂中配置了它，如果重试后失败，我希望它回到队列中。我确定我在这里缺少理解。

@SpringBootApplication
public class MsgRequeExampleApplication {

    public static void main(String[] args) {
        SpringApplication.run(MsgRequeExampleApplication.class, args);
    }

    @Bean(name = "myContainerFactory")
    public SimpleRabbitListenerContainerFactory rabbitListenerContainerFactory(ConnectionFactory connectionFactory) {
        SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory();
        factory.setConnectionFactory(connectionFactory);
        factory.setMessageConverter(new Jackson2JsonMessageConverter());
        factory.setMissingQueuesFatal(false);

        FixedBackOffPolicy backOffPolicy = new FixedBackOffPolicy();
        backOffPolicy.setBackOffPeriod(500);
        factory.setAdviceChain(new Advice[] { org.springframework.amqp.rabbit.config.RetryInterceptorBuilder.stateless()
                .maxAttempts(2).backOffPolicy(backOffPolicy).build() });
        return factory;
    }

    @RabbitListener(queues = "test", containerFactory = "myContainerFactory")
    public void processAdvisory(Message message) throws MyBusinessException {
        try{
            //Simulating exception while processing message
            String nullString=null;
            nullString.length();
        }catch(Exception ex){
            throw new MyBusinessException(ex.getMessage());
        }
    }

    public class MyBusinessException extends Exception {
        public MyBusinessException(String msg) {
            super(msg);
        }
    }

}

Answer 1

SimpleMessageListenerContainerJavaDocs 中有一个很好的描述：

/**
 * Set the default behavior when a message is rejected, for example because the listener
 * threw an exception. When true, messages will be requeued, when false, they will not. For
 * versions of Rabbit that support dead-lettering, the message must not be requeued in order
 * to be sent to the dead letter exchange. Setting to false causes all rejections to not
 * be requeued. When true, the default can be overridden by the listener throwing an
 * {@link AmqpRejectAndDontRequeueException}. Default true.
 * @param defaultRequeueRejected true to reject by default.
 */
public void setDefaultRequeueRejected(boolean defaultRequeueRejected) {
    this.defaultRequeueRejected = defaultRequeueRejected;
}

这对你有意义吗？

更新

要重试后重新排队排出需要配置一些习俗MessageRecoverer上RetryInterceptorBuilder的代码，如：

.recoverer((message, cause) -> {
        ReflectionUtils.rethrowRuntimeException(cause);
})

这样，异常将被抛出到侦听器容器，并根据它defaultRequeueRejected的消息将重新排队或不排队。