vue-java-tutorials/mq-demo/ReadMe.md

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RabbitMQ

基本示例

生产者

@SpringBootTest
class MqDemoApplicationTests {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    /**
     * 1. 测试发送消息,示例代码
     * 2. 测试成功的情况
     */
    @Test
    void publishTest() {
        String exchangeDirect = RabbitMQMessageListenerConstants.EXCHANGE_DIRECT;
        String routingKeyDirect = RabbitMQMessageListenerConstants.ROUTING_KEY_DIRECT;
        rabbitTemplate.convertAndSend(exchangeDirect, routingKeyDirect, "你好小球球~~~");

        Bunny bunny = Bunny.builder().rabbitName("Bunny").age(2).build();
        rabbitTemplate.convertAndSend(exchangeDirect, routingKeyDirect, JSON.toJSONString(bunny));
    }

}

消费者

@Component
@Slf4j
public class MessageListenerOrder {

    @RabbitListener(bindings = @QueueBinding(
            exchange = @Exchange(value = EXCHANGE_DIRECT),
            value = @Queue(value = QUEUE_NAME, durable = "true"),
            key = ROUTING_KEY_DIRECT
    )
    )
    public void processMessage(String dataString, Message message, Channel channel) {
        System.out.println("消费端接受消息:" + dataString);
    }

}

可靠性

在Rabbi中队列和交换机都是持久化的自动删除都是False。

生产者确认

配置文件

rabbitmq:
  host: ${bunny.rabbitmq.host}
  port: ${bunny.rabbitmq.port}
  username: ${bunny.rabbitmq.username}
  password: ${bunny.rabbitmq.password}
  virtual-host: ${bunny.rabbitmq.virtual-host}
  publisher-confirm-type: correlated # 交换机确认
  publisher-returns: true # 队列确认

RabbitMQ配置

[!NOTE]
@PostConstruct 注解
作用在Bean依赖注入完成后执行初始化方法构造器之后afterPropertiesSet()之前)。

特点

  • 方法需无参、返回void,名称任意
  • 执行顺序:构造器 → 依赖注入 → @PostConstruct
  • 若抛出异常Bean创建会失败

注意

  • 代理类(如@Transactional)中,会在原始对象初始化时调用
  • prototype作用域的Bean每次创建均会执行
  • 避免耗时操作,推荐轻量级初始化

替代方案
InitializingBean接口 或 @Bean(initMethod="xxx")

@Slf4j
@Configuration
@RequiredArgsConstructor
public class RabbitConfiguration implements RabbitTemplate.ConfirmCallback, RabbitTemplate.ReturnsCallback {

    private final RabbitTemplate rabbitTemplate;

    @PostConstruct
    public void initRabbitTemplate() {
        rabbitTemplate.setConfirmCallback(this);
        rabbitTemplate.setReturnsCallback(this);
    }

    @Override
    public void confirm(CorrelationData correlationData, boolean ack, String cause) {
        System.out.println("============correlationData <回调函数打印> = " + correlationData);
        System.out.println("============ack <输出> = " + ack);
        System.out.println("============cause <输出> = " + cause);
    }

    @Override
    public void returnedMessage(ReturnedMessage returnedMessage) {
        // 发送到队列失败才会走这个
        log.error("消息主体:{}", returnedMessage.getMessage().getBody());
        log.error("应答码:{}", returnedMessage.getReplyCode());
        log.error("消息使用的父交换机:{}", returnedMessage.getExchange());
        log.error("消息使用的路由键:{}", returnedMessage.getRoutingKey());
    }
}

测试失败的情况

交换机找不到

/* 测试失败交换机的情况 */
@Test
void publishExchangeErrorTest() {
    String exchangeDirect = RabbitMQMessageListenerConstants.EXCHANGE_DIRECT;
    String routingKeyDirect = RabbitMQMessageListenerConstants.ROUTING_KEY_DIRECT;
    rabbitTemplate.convertAndSend(exchangeDirect, routingKeyDirect, "----失败的消息发送----");

    Bunny bunny = Bunny.builder().rabbitName("Bunny").age(2).build();
    rabbitTemplate.convertAndSend(exchangeDirect + "~", routingKeyDirect, JSON.toJSONString(bunny));
}

队列找不到

/* 测试失败队列的情况 */
@Test
void publishQueueErrorTest() {
    String exchangeDirect = RabbitMQMessageListenerConstants.EXCHANGE_DIRECT;
    String routingKeyDirect = RabbitMQMessageListenerConstants.ROUTING_KEY_DIRECT;
    rabbitTemplate.convertAndSend(exchangeDirect, routingKeyDirect, "----失败的队列发送----");

    Bunny bunny = Bunny.builder().rabbitName("Bunny").age(2).build();
    rabbitTemplate.convertAndSend(exchangeDirect, routingKeyDirect + "~", JSON.toJSONString(bunny));
}

备份交换机

[!NOTE]

创建好的交换机是无法修改的,只能删除重新建立。

创建广播类型的交换机,因为没有路由键,只能通过广播的方式去找。

image-20250519104914787

创建与备份交换机的队列,交换机是广播的模式,不指定路由键。

image-20250519105042156

通过指定Alternate exchange的交换机进行绑定。第一个填写的不是备份交换机,是投递交换机,之后通过Alternate exchange绑定备份的交换机。

image-20250519105250365