RabbitMq | 死信队列

在定义业务队列的时候，可以考虑指定一个死信交换机，并绑定一个死信队列，当消息变成死信时，该消息就会被发送到该死信队列上，这样就方便我们查看消息失败的原因了

创建配置文件，建造交换机和短信以及邮件队列

package com.sun.springboot.config;

import java.util.HashMap;
import java.util.Map;

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.DirectExchange;
import org.springframework.amqp.core.FanoutExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;

//Fanout 类型 发布订阅模式
@Component
public class FanoutConfig {

	/**
	 * 定义死信队列相关信息
	 */
	public final static String deadQueueName = "dead_queue";
	public final static String deadRoutingKey = "dead_routing_key";
	public final static String deadExchangeName = "dead_exchange";
	/**
	 * 死信队列 交换机标识符
	 */
	public static final String DEAD_LETTER_QUEUE_KEY = "x-dead-letter-exchange";
	/**
	 * 死信队列交换机绑定键标识符
	 */
	public static final String DEAD_LETTER_ROUTING_KEY = "x-dead-letter-routing-key";

	// 邮件队列
	private String FANOUT_EMAIL_QUEUE = "fanout_email_queue";

	// 短信队列
	private String FANOUT_SMS_QUEUE = "fanout_sms_queue";
	// fanout 交换机
	private String EXCHANGE_NAME = "fanoutExchange";

	// 1.定义邮件队列
	@Bean
	public Queue fanOutEamilQueue() {
		// 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(DEAD_LETTER_QUEUE_KEY, deadExchangeName);
		args.put(DEAD_LETTER_ROUTING_KEY, deadRoutingKey);
		Queue queue = new Queue(FANOUT_EMAIL_QUEUE, true, false, false, args);
		return queue;
	}

	// 2.定义短信队列
	@Bean
	public Queue fanOutSmsQueue() {
		return new Queue(FANOUT_SMS_QUEUE);
	}

	// 2.定义交换机
	@Bean
	FanoutExchange fanoutExchange() {
		return new FanoutExchange(EXCHANGE_NAME);
	}

	// 3.队列与交换机绑定邮件队列
	@Bean
	Binding bindingExchangeEamil(Queue fanOutEamilQueue, FanoutExchange fanoutExchange) {
		return BindingBuilder.bind(fanOutEamilQueue).to(fanoutExchange);
	}

	// 4.队列与交换机绑定短信队列
	@Bean
	Binding bindingExchangeSms(Queue fanOutSmsQueue, FanoutExchange fanoutExchange) {
		return BindingBuilder.bind(fanOutSmsQueue).to(fanoutExchange);
	}

	/**
	 * 配置死信队列
	 *
	 * @return
	 */
	@Bean
	public Queue deadQueue() {
		Queue queue = new Queue(deadQueueName, true);
		return queue;
	}

	@Bean
	public DirectExchange deadExchange() {
		return new DirectExchange(deadExchangeName);
	}

	@Bean
	public Binding bindingDeadExchange(Queue deadQueue, DirectExchange deadExchange) {
		return BindingBuilder.bind(deadQueue).to(deadExchange).with(deadRoutingKey);
	}

}

将普通队列绑定到死信队列交换机上

	@Bean
	public Queue fanOutEamilQueue() {
		
		Map<String, Object> args = new HashMap<>(2);
		args.put(DEAD_LETTER_QUEUE_KEY, deadExchangeName);
		args.put(DEAD_LETTER_ROUTING_KEY, deadRoutingKey);
		Queue queue = new Queue(FANOUT_EMAIL_QUEUE, true, false, false, args);
		return queue;
	}

控制台展示：

生产者发送消息：

import java.util.UUID;

import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.core.MessageBuilder;
import org.springframework.amqp.core.MessageProperties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

import com.alibaba.fastjson.JSONObject;
    @Test
    public void test6 () throws JSONException {
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("email", "644064779");
        jsonObject.put("timestamp", 0);

        String jsonString = jsonObject.toString();
        System.out.println("jsonString:" + jsonString);
        // 生产者发送消息的时候需要设置消息id
        MessageBuilder body = MessageBuilder.withBody(jsonString.getBytes());
        System.out.println("body = " + body);
        Message message = MessageBuilder.withBody(jsonString.getBytes())
                .setContentType(MessageProperties.CONTENT_TYPE_JSON).setContentEncoding("utf-8")
                .setMessageId(UUID.randomUUID() + "").build();

        System.out.println(message.getMessageProperties());
        System.out.println("message = " + message);
        amqpTemplate.convertAndSend("fanout_email_queue", "sssss");


    }

    @RabbitListener(queues = "fanout_email_queue")
    public void process(Message message, @Headers Map<String, Object> headers, Channel channel) throws Exception {
        String messageId = message.getMessageProperties().getMessageId();
        String msg = new String(message.getBody(), "UTF-8");
        System.out.println("邮件消费者获取生产者消息msg:" + msg + ",消息id:" + messageId);

        try {
            int result = 1 / 0;
            System.out.println("result:" + result);
            // 通知mq服务器删除该消息
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
        } catch (Exception e) {
        e.printStackTrace();
        // // 丢弃该消息
        channel.basicNack(message.getMessageProperties().getDeliveryTag(), false, false);
        }
        }

死信队列收到消息