RabbitMQ代码篇之过期时间，死信队列，延迟队列，优先级队列的基本使用

// nack 返回 false，并放弃重新回到队列
channel.basicNack(deliveryTag, false, false);

//拒绝，不重新入队列
channel.basicReject(deliveryTag, false);

@Bean
public DirectExchange directExchange2() {
    /**
     * 交换机名，后面两个是默认值就：持久化，不自动删除
     */
    return new DirectExchange(RabbitMQConstants.DIRECT_EXCHANGE2, true, false);
}

@Bean
public Queue directQueue2() {
    return QueueBuilder
            .durable(RabbitMQConstants.DIRECT_QUEUE2)
            .deadLetterExchange(RabbitMQConstants.DLX_EXCHANGE)
            .deadLetterRoutingKey(RabbitMQConstants.DLX_ROUTING_KEY)
            .build();
}

/**
 * 将队列绑定到交换机上
 *
 * @return
 */
@Bean
public Binding directBinding2() {
    return BindingBuilder.
            bind(directQueue2()).
            to(directExchange2()).
            with(RabbitMQConstants.DIRECT_BINDING_KEY2);
}

/**
 * 创建队列时设置
 * @return
 */
@Bean
public Queue ttlQueue() {
    Map<String, Object> args = new HashMap<>();
    //设置消息过期时间
    args.put("x-message-ttl", 5000);
    //设置死信交换机
    args.put("x-dead-letter-exchange", RabbitMQConstants.DLX_EXCHANGE);
    //设置死信 routing_key
    args.put("x-dead-letter-routing-key", RabbitMQConstants.DLX_ROUTING_KEY);
    return new Queue(RabbitMQConstants.TTL_QUEUE, true, false, false, args);
}

/**
 * 发送消息时设置
 * @return
 */
public void sendMessage2() throws JsonProcessingException {
    User user = new User();
    ObjectMapper objectMapper = new ObjectMapper();
    byte[] bytes = objectMapper.writeValueAsBytes(user);

    // 10 s 后过期
    Message message =
            MessageBuilder.withBody(bytes)
                    .setExpiration("10000").build();


    // 交换机，路由键，信息
    rabbitTemplate.convertAndSend(
            RabbitMQConstants.DIRECT_EXCHANGE2,
            RabbitMQConstants.DIRECT_ROUTING_KEY2,
            message
    );

}

// 延迟交换机
    @Bean
    public CustomExchange delayedExchange() {
        Map<String, Object> args = new HashMap<>();
        // 交换机类型
        args.put("x-delayed-type", "direct");
        return new CustomExchange(RabbitMQConstants.DELAY_EXCHANGE, "x-delayed-message", true, false, args);
    }

    public void sendMessage() throws JsonProcessingException {
        User user = new User();
        ObjectMapper objectMapper = new ObjectMapper();
        byte[] bytes = objectMapper.writeValueAsBytes(user);

        //延迟 10 s
        Message message = MessageBuilder.withBody(bytes).setHeader("x-delay", 10_000).build();

        // 交换机，路由键，信息
        rabbitTemplate.convertAndSend(
                RabbitMQConstants.DELAY_EXCHANGE,
                RabbitMQConstants.DELAY_ROUTING_KEY,
                message
        );
    }

@Bean
public Queue directPriorityQueue() {
    Map<String, Object> args = new HashMap<>();
   // 最大优先级
    args.put("x-max-priority", 10);
    return new Queue(RabbitMQConstants.PRIORITY_QUEUE, true, false, false, args);
}

public void sendMessage() throws Exception {
        User user = new User();
        ObjectMapper objectMapper = new ObjectMapper();

        // 交换机，路由键，信息, 优先级 5
        retryRabbitTemplate.convertAndSend(
                RabbitMQConstants.PRIORITY_EXCHANGE,
                RabbitMQConstants.PRIORITY_ROUTING_KEY,
                MessageBuilder.withBody( objectMapper.writeValueAsBytes(user.setPriority(5))).setPriority(5).build()
        );

    }