RabbitMQ消息分发模式

RabbitMQ 默认采用轮询的方式分发消息，当一个消息需要有多个消费者都消费时，需要创建多个队列实现，示例如下：

@Component
public class SimpleConsume {

    @RabbitListener(
            bindings =
            @QueueBinding(
                    value = @Queue(durable = "true"), // 不指定队列名称，系统会自动生成队列名
                    exchange = @Exchange(value = "simpleExchange",
                            type = "topic"),
                    key = "simple.*"
            )
    )
    public void onMessage(Message message, Channel channel) throws Exception {
        System.err.println("--------------------------------------");
        System.err.println("消费端Payload: " + message.getPayload());
        Long deliveryTag = (Long) message.getHeaders().get(AmqpHeaders.DELIVERY_TAG);
        //手工ACK
        channel.basicAck(deliveryTag, false);
    }

}

@SpringBootTest
public class Producer {
    @Autowired
    private RabbitTemplate rabbitTemplate;
    
	@Test
    public void sendSimpleMessage() {
        String exchange = "simpleExchange";
        String routingKey = "simple.message";
        for(int i=0;i<5;i++) {
            rabbitTemplate.convertAndSend(exchange, routingKey, "hello simpleExchange ===="+ i);
        }
    }
}    

启动两个端口不同的项目：执行 sendSimpleMessage 方法，查看控制台输出：

端口 8080 控制台:

--------------------------------------
消费端Payload: hello simpleExchange ====0
--------------------------------------
消费端Payload: hello simpleExchange ====1
--------------------------------------
消费端Payload: hello simpleExchange ====2
--------------------------------------
消费端Payload: hello simpleExchange ====3
--------------------------------------
消费端Payload: hello simpleExchange ====4

端口 8081 控制台:

--------------------------------------
消费端Payload: hello simpleExchange ====0
--------------------------------------
消费端Payload: hello simpleExchange ====1
--------------------------------------
消费端Payload: hello simpleExchange ====2
--------------------------------------
消费端Payload: hello simpleExchange ====3
--------------------------------------
消费端Payload: hello simpleExchange ====4

可以看到两个消费者都可以消费到所有消息了。