RabbitMQ订阅者模式-蒲公英云

RabbitMQ订阅者模式

订阅者模式

一个生产者，多个消费者
每一个消费者，都有一个独立的队列
生产者没有将消息直接发送到队列，而是发送到了交换机

每个队列都要绑定到交换机
生产者发送的消息，经过交换机，到达队列
实现，一个消息被多个消费者获取的目的

注意
消息发送到没有队列绑定的交换机时，消息将丢失
因为，交换机没有存储消息的能力，消息只能存在在队列中
这里写图片描述

Send

生产者

package cn.itcast.rabbitmq.ps;
import cn.itcast.rabbitmq.util.ConnectionUtil;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
public class Send {
    private final static String EXCHANGE_NAME = "test_exchange_fanout";
    public static void main(String[] argv) throws Exception {
        // 获取到连接以及mq通道
        Connection connection = ConnectionUtil.getConnection();
        Channel channel = connection.createChannel();
        // 声明exchange
        channel.exchangeDeclare(EXCHANGE_NAME, "fanout");
        // 消息内容
        String message = "消息已经修改，商品id=1000";
        channel.basicPublish(EXCHANGE_NAME, "", null, message.getBytes());
        System.out.println(" [x] Sent '" + message + "'");
        channel.close();
        connection.close();
    }
}

Recv

消费者1

package cn.itcast.rabbitmq.ps;
import cn.itcast.rabbitmq.util.ConnectionUtil;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.QueueingConsumer;
public class Recv { 
    private final static String QUEUE_NAME = "test_queue_work";
    private final static String EXCHANGE_NAME = "test_exchange_fanout";
    public static void main(String[] argv) throws Exception {
        // 获取到连接以及mq通道
        Connection connection = ConnectionUtil.getConnection();
        Channel channel = connection.createChannel();
        // 声明队列
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        // 绑定队列到交换机
        channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "");
        // 同一时刻服务器只会发一条消息给消费者
        channel.basicQos(1);
        // 定义队列的消费者
        QueueingConsumer consumer = new QueueingConsumer(channel);
        // 监听队列，手动返回完成
        channel.basicConsume(QUEUE_NAME, false, consumer);
        // 获取消息
        while (true) {
            QueueingConsumer.Delivery delivery = consumer.nextDelivery();
            String message = new String(delivery.getBody());
            System.out.println(" [x] Received '" + message + "'");
            Thread.sleep(10);
            channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
        }
    }
}

Recv2

消费者2

package cn.itcast.rabbitmq.ps;
import cn.itcast.rabbitmq.util.ConnectionUtil;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.QueueingConsumer;
public class Recv2 { 
    private final static String QUEUE_NAME = "test_queue_work2";
    private final static String EXCHANGE_NAME = "test_exchange_fanout";
    public static void main(String[] argv) throws Exception {
        // 获取到连接以及mq通道
        Connection connection = ConnectionUtil.getConnection();
        Channel channel = connection.createChannel();
        // 声明队列
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        // 绑定队列到交换机
        channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "");
        // 同一时刻服务器只会发一条消息给消费者
        channel.basicQos(1);
        // 定义队列的消费者
        QueueingConsumer consumer = new QueueingConsumer(channel);
        // 监听队列，手动返回完成
        channel.basicConsume(QUEUE_NAME, false, consumer);
        // 获取消息
        while (true) {
            QueueingConsumer.Delivery delivery = consumer.nextDelivery();
            String message = new String(delivery.getBody());
            System.out.println(" [x] Received '" + message + "'");
            Thread.sleep(10);
            channel.basicAck(delivery.getEnvelope().getDeliveryTag(), false);
        }
    }
}