RabbitMQ之Topic

最新推荐文章于 2025-05-20 20:56:55 发布

原创最新推荐文章于 2025-05-20 20:56:55 发布 · 942 阅读

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文章标签：

#java-rabbitmq #rabbitmq #java

本文详细介绍了在使用RabbitMQ的Topic交换机时如何正确设置消息的路由键。通过示例展示了如何利用通配符实现灵活的消息路由，并提供了生产者及消费者的具体实现代码。

发送到类型是topic交换机的消息的routing_key不能随意写，必须满足一定的要求，它必须是一个单词列表，以点号分隔开。这些单词可以是任意单词，比如说：“stock.usd.nyse”,“nyse,vmw”,"quick.orange.rabbit"这种类型的。当然这个单词列表最多不能超过255个字节
在这个规则列表里，其中有两个替换符是大家需要注意的
(星号)可以代替一个单词
#(井号)可以替代零个或多个单词

Q1–>绑定的是中间带 orange 带 3 个单词的字符串(.orange.)
Q2–>绑定的是
最后一个单词是 rabbit 的 3 个单词(.*.rabbit)
第一个单词是 lazy 的多个单词(lazy.#)

生产者代码：

package com.atguigu.rabbitmq.seven;

import com.atguigu.rabbitmq.utils.RabbitMqUtils;
import com.rabbitmq.client.Channel;

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

public class EmitLogTopic {
    private static final String EXCHANGE_NAME = "topic_logs";

    public static void main(String[] args) throws Exception {
        try (Channel channel = RabbitMqUtils.getChannel()) {
            channel.exchangeDeclare(EXCHANGE_NAME, "topic");
            Map<String, String> bindingKeyMap = new HashMap<>();
            bindingKeyMap.put("quick.orange.rabbit","被队列 Q1Q2 接收到");
            bindingKeyMap.put("lazy.orange.elephant","被队列 Q1Q2 接收到");
            bindingKeyMap.put("quick.orange.fox","被队列 Q1 接收到");
            bindingKeyMap.put("lazy.brown.fox","被队列 Q2 接收到");

            bindingKeyMap.put("lazy.pink.rabbit","虽然满足两个绑定但只被队列 Q2 接收一次");
            bindingKeyMap.put("quick.brown.fox","不匹配任何绑定不会被任何队列接收到会被丢弃");
            bindingKeyMap.put("quick.orange.male.rabbit","是四个单词不匹配任何绑定会被丢弃");
            bindingKeyMap.put("lazy.orange.male.rabbit","是四个单词但匹配 Q2");


            for (Map.Entry<String, String> bindingKeyEntry: bindingKeyMap.entrySet()){
                String bindingKey = bindingKeyEntry.getKey();
                String message = bindingKeyEntry.getValue();
                channel.basicPublish(EXCHANGE_NAME,bindingKey, null,
                        message.getBytes("UTF-8"));
                System.out.println("生产者发出消息" + message);
            }
        }



    }
}

消费者1代码：

package com.atguigu.rabbitmq.seven;

import com.atguigu.rabbitmq.utils.RabbitMqUtils;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DeliverCallback;

public class ReceiveLogsTopic01 {

    private static final String EXCHANGE_NAME = "topic_logs";

    public static void main(String[] argv) throws Exception {

        Channel channel = RabbitMqUtils.getChannel();
        channel.exchangeDeclare(EXCHANGE_NAME, "topic");

        //声明 Q1 队列与绑定关系
        String queueName="Q1";
        channel.queueDeclare(queueName, false, false, false, null);
        channel.queueBind(queueName, EXCHANGE_NAME, "*.orange.*");

        System.out.println("等待接收消息.....");


        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" 接收队列 :"+queueName+" 绑 定 键:"+delivery.getEnvelope().getRoutingKey()+",消息:"+message);
        };

        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
        });
    }

}

消费者2代码

package com.atguigu.rabbitmq.seven;

import com.atguigu.rabbitmq.utils.RabbitMqUtils;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DeliverCallback;

public class ReceiveLogsTopic02 {

    private static final String EXCHANGE_NAME = "topic_logs";

    public static void main(String[] argv) throws Exception {

        Channel channel = RabbitMqUtils.getChannel();
        channel.exchangeDeclare(EXCHANGE_NAME, "topic");

        //声明 Q1 队列与绑定关系
        String queueName="Q1";
        channel.queueDeclare(queueName, false, false, false, null);
        channel.queueBind(queueName, EXCHANGE_NAME, "*.*.rabbit");
        channel.queueBind(queueName, EXCHANGE_NAME, "lazy.#");

        System.out.println("等待接收消息.....");


        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" 接收队列 :"+queueName+" 绑 定 键:"+delivery.getEnvelope().getRoutingKey()+",消息:"+message);
        };

        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
        });
    }

}