RabbitMQ入门-发布订阅模式

Posted 2020-10-25 小LUA

兔子的Publish/Subscribe是这样的：

有个生产者P，X代表交换机，交换机绑定队列，消费者从队列中取得消息。每次有消息，先发到交换机中，然后由交换机负责发送到它已知的队列中。

 

生产者代码：

package com.example.demo;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

/**
 * 
 * 4种交换类型
 * There are a few exchange types available: direct, topic, headers and fanout.
 * 扇出交换：将收到的消息广播到它所知道的所有队列里
 */
public class PSSend {

    private static final String EXCHANGE_NAME = "logs";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();    // 连接工厂
        factory.setHost("localhost");
        Connection connection = factory.newConnection();        // 获取连接
        Channel channel = connection.createChannel();

        // 当我们发送时，需要一个路由密钥，但是对于扇出交换，他的值将被忽略
        // 第一个参数为交换的名字，第二个为交换的类型
        channel.exchangeDeclare(EXCHANGE_NAME, "fanout");

        String msg = "发布订阅";
        channel.basicPublish(EXCHANGE_NAME, "", null, msg.getBytes());
        System.out.println("PS-Send:" + msg);

        channel.close();
        connection.close();

    }

}

 

 消费者：

package com.example.demo;

import com.rabbitmq.client.*;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

/**
 * 
 *
 * There are a few exchange types available: direct, topic, headers and fanout.
 * 扇出交换：将收到的消息广播到它所知道的所有队列里
 */
public class PSReceive {

    private static final String EXCHANGE_NAME = "logs";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();    // 连接工厂
        factory.setHost("localhost");
        Connection connection = factory.newConnection();        // 获取连接
        Channel channel = connection.createChannel();

        // 当我们发送时，需要一个路由密钥，但是对于扇出交换，他的值将被忽略
        // 第一个参数为交换的名字，第二个为交换的类型
        channel.exchangeDeclare(EXCHANGE_NAME, "fanout");

        // 当声明队列，不加任何参数，产生的将是一个临时队列，getQueue返回的是队列名称
        String queueA = channel.queueDeclare().getQueue();
        //String queueB = channel.queueDeclare().getQueue();
        System.out.println("临时队列：" + queueA);

        // 下面绑定交换与队列
        channel.queueBind(queueA, EXCHANGE_NAME, "");
        //channel.queueBind(queueB, EXCHANGE_NAME, "");

        Consumer consumer = new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                String recv = new String(body, "UTF-8");
                System.out.println("PS-Receive:" + recv);
            }
        };

        channel.basicConsume(queueA, true, consumer);
        //channel.basicConsume(queueB, true, consumer);


    }

}

 

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