五分钟带你玩转rabbitmq（五）死信队列

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>

server:
  port: 8088
spring:
  rabbitmq:
    host: 192.168.*.*
    port: 5672
    username: root
    password: root
    virtual-host: /
    listener:
      simple:
        acknowledge-mode: manual  #手动应答
        prefetch: 1 # 每次只处理一个信息
    publisher-confirms: true #开启消息确认机制
    publisher-returns: true #支持消息发送失败返回队列

@Configuration
public class RabbitMqConfig {
    /**
     * 连接工厂
     */
    @Autowired
    private ConnectionFactory connectionFactory;
    /**
     * 定制化amqp模版
     *
     * ConfirmCallback接口用于实现消息发送到RabbitMQ交换器后接收ack回调 即消息发送到exchange ack
     * ReturnCallback接口用于实现消息发送到RabbitMQ 交换器，但无相应队列与交换器绑定时的回调 即消息发送不到任何一个队列中 ack
     */
    @Bean
    public RabbitTemplate rabbitTemplate() {
        Logger logger = LoggerFactory.getLogger(RabbitTemplate.class);
        RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
        // 消息发送失败返回到队列中, yml需要配置 publisher-returns: true
        rabbitTemplate.setMandatory(true);
        // 发送消息确认, yml需要配置 publisher-confirms: true
        rabbitTemplate.setConfirmCallback(msgSendConfirmCallBack());
        // 消息返回, yml需要配置 publisher-returns: true
        rabbitTemplate.setReturnCallback((message, replyCode, replyText, exchange, routingKey) -> {
            String correlationId = message.getMessageProperties().getCorrelationId().toString();
            logger.debug("消息：{} 发送失败, 应答码：{} 原因：{} 交换机: {}  路由键: {}", correlationId, replyCode, replyText, exchange,
                routingKey);
        });
        return rabbitTemplate;
    }
    /**
     * 确认发送消息是否成功(调用util方法)
     *
     * @return
     */
    @Bean
    public MsgSendConfirmCallBack msgSendConfirmCallBack() {
        return new MsgSendConfirmCallBack();
    }
}

public class MsgSendConfirmCallBack implements RabbitTemplate.ConfirmCallback {
    /**
     * 回调方法
     * @param correlationData
     * @param ack
     * @param cause
     */
    @Override
    public void confirm(CorrelationData correlationData, boolean ack, String cause) {
        System.out.println("MsgSendConfirmCallBack  , 回调id:" + correlationData);
        if (ack) {
            System.out.println("消息发送成功");
        } else {
            //可以将消息写入本地，使用定时任务重新发送
            System.out.println("消息发送失败:" + cause + "\n重新发送");
        }
    }
}

@Configuration
public class BusinessConfig {
    /**
     * 业务1模块direct交换机的名字
     */
    public static final String YEWU1_EXCHANGE = "yewu1_direct_exchange";
    /**
     * 业务1 demo业务的队列名称
     */
    public static final String YEWU1_DEMO_QUEUE = "yewu1_demo_queue";
    /**
     * 业务1 demo业务的routekey
     */
    public static final String YEWU1_DEMO_ROUTINGKEY = "yewu1_demo_key";
    @Bean
    public Queue yewu1DemoDeadQueue() {
        // 将普通队列绑定到死信队列交换机上
        Map<String, Object> args = new HashMap<>(2);
        args.put(RetryConfig.RETRY_LETTER_QUEUE_KEY, DeadConfig.FAIL_EXCHANGE_NAME);
        args.put(RetryConfig.RETRY_LETTER_ROUTING_KEY, DeadConfig.FAIL_ROUTING_KEY);
        return new Queue("yewu1_demo_dead_queue", true, false, false, args);
    }
    /**
     * 将消息队列和交换机进行绑定
     */
    @Bean
    public Binding binding_one() {
        return BindingBuilder.bind(yewu1DemoDeadQueue()).to(yewu1Exchange())
            .with("yewu1_demo_dead_key");
    }
}

@Configuration
public class DeadConfig {
    /**
     * 死信队列
     */
    public final static String FAIL_QUEUE_NAME = "fail_queue";
    /**
     * 死信交换机
     */
    public final static String FAIL_EXCHANGE_NAME = "fail_exchange";
    /**
     * 死信routing
     */
    public final static String FAIL_ROUTING_KEY = "fail_routing";
    /**
     * 创建配置死信队列
     *
     */
    @Bean
    public Queue deadQueue() {
        return new Queue(FAIL_QUEUE_NAME, true, false, false);
    }
    /**
     * 死信交换机
     *
     * @return
     */
    @Bean
    public DirectExchange deadExchange() {
        DirectExchange directExchange = new DirectExchange(FAIL_EXCHANGE_NAME, true, false);
        return directExchange;
    }
    /**
     * 绑定关系
     * 
     * @return
     */
    @Bean
    public Binding failBinding() {
        return BindingBuilder.bind(deadQueue()).to(deadExchange()).with(FAIL_ROUTING_KEY);
    }
}

public enum RabbitEnum {
    /**
     * 处理成功
     */
    ACCEPT,
    /**
     * 可以重试的错误
     */
    RETRY,
    /**
     * 无需重试的错误
     */
    REJECT

@RequestMapping("/sendDirectDead")
        String sendDirectDead(@RequestBody String message) throws Exception {
        System.out.println("开始生产");
        CorrelationData data = new CorrelationData(UUID.randomUUID().toString());
        rabbitTemplate.convertAndSend(BusinessConfig.YEWU1_EXCHANGE, "yewu1_demo_dead_key",
                message, data);
        System.out.println("结束生产");
        System.out.println("发送id:" + data);
        return "OK,sendDirect:" + message;
    }

    @RabbitListener(queues = "yewu1_demo_dead_queue")
    protected void consumerDead(Message message, Channel channel) throws Exception {
        RabbitEnum ackSign = RabbitEnum.RETRY;
        try {
            int i = 10 / 0;
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
        } catch (Exception e) {
            ackSign = RabbitEnum.RETRY;
            throw e;
        } finally {
            // 通过finally块来保证Ack/Nack会且只会执行一次
            if (ackSign == RabbitEnum.ACCEPT) {
                channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
            } else if (ackSign == RabbitEnum.RETRY) {
                channel.basicNack(message.getMessageProperties().getDeliveryTag(), false, false);
            }
        }
    }