rabbitmq主题模式

rabbitmq主题模式

主题模式可以实现动态路由的匹配，对应的交换机类型为topic

topic交换机的routingKey不能随意写，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，eg："stock.usd.nyse"、 "nyse.vmw"、"quick.orange.rabbit"。且这个单词列表最多不能超过 255 个字节

在这个规则列表中，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

当队列绑定关系是下列这种情况时需要引起注意

• 当一个队列绑定键是#，那么这个队列将接收所有数据，就有点像fanout
• 如果队列绑定键当中没有#和*出现，那么该队列绑定类型就是direct

代码实现

设置消费者A的routingKey为*.b.*，注意：声明的交换机类型为BuiltinExchangeType.TOPIC

package com.yl.topic;

import com.rabbitmq.client.*;
import com.yl.util.RabbitConstant;
import com.yl.util.RabbitUtils;

import java.io.IOException;

/**
 * 消费者A
 *
 * @author Y-wee
 */
public class TopicConsumerA {

    public static void main(String[] args) throws IOException {
        Connection connection = RabbitUtils.getConnection();
        Channel channel = connection.createChannel();
        channel.exchangeDeclare(RabbitConstant.EXCHANGE_TOPIC, BuiltinExchangeType.TOPIC);
        channel.queueDeclare(RabbitConstant.QUEUE_TOPIC_A,false,false,false,null);
        channel.queueBind(RabbitConstant.QUEUE_TOPIC_A, RabbitConstant.EXCHANGE_TOPIC,"*.b.*");

        DeliverCallback deliverCallback = (consumerTag, message) -> {
            System.out.println("ConsumerA接收到消息:"+new String(message.getBody()));
            channel.basicAck(message.getEnvelope().getDeliveryTag(),false);
        };

        CancelCallback cancelCallback = (consumerTag) -> {
            System.out.println("消费失败");
        };

        channel.basicConsume(RabbitConstant.QUEUE_TOPIC_A, false, deliverCallback, cancelCallback);
    }

}

RabbitUtils是笔者自定义的一个工具类，用来获取连接

RabbitConstant是笔者自定义的一个常量类，里面存储了队列名和交换机名

设置消费者B的routingKey为*.*.c和a.#

package com.yl.topic;

import com.rabbitmq.client.*;
import com.yl.util.RabbitConstant;
import com.yl.util.RabbitUtils;

import java.io.IOException;

/**
 * 消费者B
 *
 * @author Y-wee
 */
public class TopicConsumerB {

    public static void main(String[] args) throws IOException {
        Connection connection = RabbitUtils.getConnection();
        Channel channel = connection.createChannel();
        channel.exchangeDeclare(RabbitConstant.EXCHANGE_TOPIC, BuiltinExchangeType.TOPIC);
        channel.queueDeclare(RabbitConstant.QUEUE_TOPIC_B,false,false,false,null);
        channel.queueBind(RabbitConstant.QUEUE_TOPIC_B, RabbitConstant.EXCHANGE_TOPIC,"*.*.c");
        channel.queueBind(RabbitConstant.QUEUE_TOPIC_B, RabbitConstant.EXCHANGE_TOPIC,"a.#");

        DeliverCallback deliverCallback = (consumerTag, message) -> {
            System.out.println("ConsumerB接收到消息:"+new String(message.getBody()));
            channel.basicAck(message.getEnvelope().getDeliveryTag(),false);
        };

        CancelCallback cancelCallback = (consumerTag) -> {
            System.out.println("消费失败");
        };

        channel.basicConsume(RabbitConstant.QUEUE_TOPIC_B, false, deliverCallback, cancelCallback);
    }

}

生产者发送消息

package com.yl.topic;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.yl.util.RabbitConstant;
import com.yl.util.RabbitUtils;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 * 生产者
 *
 * @author Y-wee
 */
public class TopicProvider {

    public static void main(String[] args) throws IOException {
        Map<String, String> map = new HashMap<>();
        map.put("aaa.b.ccc","b");
        map.put("aa.bb.c","c");
        map.put("a.bbb.ccc.ddd","a");

        Connection connection = RabbitUtils.getConnection();
        Channel channel = connection.createChannel();

        for(String key:map.keySet()){
            channel.basicPublish(RabbitConstant.EXCHANGE_TOPIC,key,null,map.get(key).getBytes());
        }

        System.out.println("消息发送完毕");
    }

}

控制台打印结果：

TopicConsumerA

ConsumerA接收到消息:b

TopicConsumerB

ConsumerB接收到消息:a
ConsumerB接收到消息:c