Rabbitmq + Spring AMQP:重发消息但不返回ack

在使用RabbitMQ和Spring AMQP时，如果你希望在消息被重发时不返回ack（acknowledge），可以通过以下步骤实现：

1. 配置RabbitMQ连接工厂： 确保你的RabbitMQ连接工厂配置正确，以便Spring AMQP能够连接到RabbitMQ服务器。 @Configuration public class RabbitConfig { @Bean public ConnectionFactory connectionFactory() { CachingConnectionFactory connectionFactory = new CachingConnectionFactory("localhost"); connectionFactory.setUsername("guest"); connectionFactory.setPassword("guest"); return connectionFactory; } @Bean public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory) { RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory); // 配置重发策略 rabbitTemplate.setRetryTemplate(retryTemplate()); return rabbitTemplate; } @Bean public RetryTemplate retryTemplate() { RetryTemplate retryTemplate = new RetryTemplate(); ExponentialBackOffPolicy backOffPolicy = new ExponentialBackOffPolicy(); backOffPolicy.setInitialInterval(1000); backOffPolicy.setMaxInterval(10000); backOffPolicy.setMultiplier(2.0); retryTemplate.setBackOffPolicy(backOffPolicy); SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy(); retryPolicy.setMaxAttempts(5); retryTemplate.setRetryPolicy(retryPolicy); return retryTemplate; } }
2. 配置消息监听器容器工厂： 配置消息监听器容器工厂，以便在消息处理失败时进行重发。 @Configuration public class RabbitListenerConfig { @Bean public SimpleRabbitListenerContainerFactory rabbitListenerContainerFactory(ConnectionFactory connectionFactory) { SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory(); factory.setConnectionFactory(connectionFactory); factory.setRetryTemplate(retryTemplate()); factory.setAcknowledgeMode(AcknowledgeMode.NONE); // 设置为NONE以禁用ack return factory; } @Bean public RetryTemplate retryTemplate() { RetryTemplate retryTemplate = new RetryTemplate(); ExponentialBackOffPolicy backOffPolicy = new ExponentialBackOffPolicy(); backOffPolicy.setInitialInterval(1000); backOffPolicy.setMaxInterval(10000); backOffPolicy.setMultiplier(2.0); retryTemplate.setBackOffPolicy(backOffPolicy); SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy(); retryPolicy.setMaxAttempts(5); retryTemplate.setRetryPolicy(retryPolicy); return retryTemplate; } }
3. 创建消息监听器： 创建一个消息监听器来处理消息。 @Component public class MyMessageListener { @RabbitListener(queues = "myQueue") public void handleMessage(String message) { // 处理消息的逻辑 System.out.println("Received message: " + message); // 故意抛出异常以测试重发 throw new RuntimeException("Message processing failed"); } }
4. 配置队列和交换机： 确保你的队列和交换机已经正确配置。 @Configuration public class RabbitConfig { @Bean public Queue myQueue() { return new Queue("myQueue", false); } @Bean public DirectExchange myExchange() { return new DirectExchange("myExchange"); } @Bean public Binding binding(Queue myQueue, DirectExchange myExchange) { return BindingBuilder.bind(myQueue).to(myExchange).with("myRoutingKey"); } }

通过以上配置，当消息处理失败时，Spring AMQP会根据重发策略自动重发消息，并且在重发过程中不会返回ack。这样可以确保消息在处理失败时能够被重新投递到队列中进行再次处理。