[大数据]rabbitMQ延迟队列实战

本次延迟队列场景，先发一个消息到队列，这个队列没有消费者，这个队列延迟n秒后，会进入下一个逻辑处理。本次逻辑是消息会进入死信队列消费。上代码

maven

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>com.rabbitmq</groupId>
            <artifactId>amqp-client</artifactId>
            <version>5.10.0</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

定义一个全局配置类，来控制队列信息。本次使用注解配置，也可以使用xml配置。

@Configuration
public class MqConfig {
    public static final String X_EXCHANGE = "X";
    public static final String QUEUE_A = "QA";
    public static final String QUEUE_B = "QB";
    public static final String Y_DEAD_LETTER_EXCHANGE = "Y";
    public static final String DEAD_LETTER_QUEUE = "QD";

    // 声明 xExchange
    @Bean("xExchange")
    public DirectExchange xExchange() {
        return new DirectExchange(X_EXCHANGE);
    }

    // 声明 xExchange
    @Bean("yExchange")
    public DirectExchange yExchange() {
        return new DirectExchange(Y_DEAD_LETTER_EXCHANGE);
    }

    // 声明队列 A ttl 为 10s 并绑定到对应的死信交换机
    @Bean("queueA")
    public Queue queueA() {
        Map<String, Object> args = new HashMap<>(3);
            // 声明当前队列绑定的死信交换机
        args.put("x-dead-letter-exchange", Y_DEAD_LETTER_EXCHANGE);
            // 声明当前队列的死信路由 key
        args.put("x-dead-letter-routing-key", "YD");
            // 声明队列的 TTL
        args.put("x-message-ttl", 10000);
        return QueueBuilder.durable(QUEUE_A).withArguments(args).build();
    }

    // 声明队列 A 绑定 X 交换机
    @Bean
    public Binding queueaBindingX(@Qualifier("queueA") Queue queueA,
                                  @Qualifier("xExchange") DirectExchange xExchange) {
        return BindingBuilder.bind(queueA).to(xExchange).with("XA");
    }

    // 声明队列 B ttl 为 40s 并绑定到对应的死信交换机
    @Bean("queueB")
    public Queue queueB() {
        Map<String, Object> args = new HashMap<>(3);
        // 声明当前队列绑定的死信交换机
        args.put("x-dead-letter-exchange", Y_DEAD_LETTER_EXCHANGE);
        // 声明当前队列的死信路由 key
        args.put("x-dead-letter-routing-key", "YD");
        // 声明队列的 TTL
        args.put("x-message-ttl", 40000);
        return QueueBuilder.durable(QUEUE_B).withArguments(args).build();
    }


    // 声明队列 B 绑定 X 交换机
    @Bean
    public Binding queuebBindingX(@Qualifier("queueB") Queue queue1B,
                                  @Qualifier("xExchange") DirectExchange xExchange) {
        return BindingBuilder.bind(queue1B).to(xExchange).with("XB");
    }

    // 声明死信队列 QD
    @Bean("queueD")
    public Queue queueD() {
        return new Queue(DEAD_LETTER_QUEUE);
    }

    // 声明死信队列 QD 绑定关系
    @Bean
    public Binding deadLetterBindingQAD(@Qualifier("queueD") Queue queueD,
                                        @Qualifier("yExchange") DirectExchange yExchange) {
        return BindingBuilder.bind(queueD).to(yExchange).with("YD");
    }
}

定义生产者

@Controller
@Slf4j
public class delayProduct {
    @Autowired
    private RabbitTemplate rabbitTemplate;

    @RequestMapping("/send/{ttl}")
    public void send(@PathVariable String ttl){
        log.info("---->send message to X whit routKey XA----->");
        rabbitTemplate.convertAndSend("X","XA",ttl);

        log.info("---->send message to X whit routKey XB----->");
        rabbitTemplate.convertAndSend("X","XB",ttl);

        log.info("send end!!!");
    }

}

?定义消费者，为了方便测试在期间消费的不再出现死信队列，我这里每个队列都定义了消费者。

@Slf4j
@Component
public class DelayComsume {

    @RabbitListener(queues = "QD")
    public void consumeQD(Message message){
        String msg = new String(message.getBody());
        log.info("QD consumer------>"+msg);
    }

    @RabbitListener(queues = "QA")
    public void consumeQA(Message message){
        String msg = new String(message.getBody());
        log.info("QA consumer------>"+msg);
    }

    @RabbitListener(queues = "QB")
    public void consumeQB(Message message) throws InterruptedException {
        Thread.sleep(3000);
        String msg = new String(message.getBody());
        log.info("QB consumer------>"+msg);
    }
}

?效果，当存在QAQB监听时，死信队列没有消费。如果去掉QAQB监听，则会在延迟时间之后进行消费

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