RabbitMQ——轮询工作队列

生产者投放生产消息，由多个消费者消费消息。

既然是轮询，那就是消费者轮着获取消息，生产者生产多条消息，消费者依次去获取消息，每次获取一条。

代码与简单队列差距不大，区别在于消费者由一个变为多个，生产者一次性生产多条消息。

通过结果不难看出，确实是每个消费者依次获取消息，这也是默认的工作队列。

        存在的问题，这种工作队列太过于理想化，并不适合实际的开发，我们难以保证每个消费者消费信息的速度相同，难免有的快有的慢，因此我们可以去人为的设置一些参数，尽量达到公平。于是也就有了公平工作队列。

package com.xxxx.work.rr.send;

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

import java.nio.charset.StandardCharsets;


public class Send {

    //定义队列名称
    private final static String QUEUE_NAME = "work-rr";

    public static void main(String[] argv) throws Exception {
        //创建连接工厂
        ConnectionFactory factory = new ConnectionFactory();
        //连接工厂配置
        factory.setHost("localhost");
        factory.setPort(5672);
        factory.setUsername("yeb");
        factory.setPassword("yeb");
        factory.setVirtualHost("/");
        //创建连接
        try (Connection connection = factory.newConnection();
             //创建信道
             Channel channel = connection.createChannel()) {
            

            channel.queueDeclare(QUEUE_NAME, false, false, false, null);
            for (int i = 0; i < 20; i++) {
                String message = "Hello World!"+i;
                //发送消息
                channel.basicPublish("", QUEUE_NAME, null, message.getBytes(StandardCharsets.UTF_8));
                System.out.println(" [x] Sent '" + message + "'" +i);
            }
        }
    }
}

package com.xxxx.work.rr.recv;

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

import java.nio.charset.StandardCharsets;


public class Recv01 {
    //定义队列名称
    private final static String QUEUE_NAME = "work-rr";

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        factory.setUsername("yeb");
        factory.setPassword("yeb");
        factory.setVirtualHost("/");
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
        //打印消息
        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), StandardCharsets.UTF_8);
            System.out.println(" [x] Received '" + message + "'");
        };
        

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

package com.xxxx.work.rr.recv;

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

import java.nio.charset.StandardCharsets;


public class Recv02 {
    //定义队列名称
    private final static String QUEUE_NAME = "work-rr";

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        factory.setUsername("yeb");
        factory.setPassword("yeb");
        factory.setVirtualHost("/");
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        System.out.println(" [*] Waiting for messages. To exit press CTRL+C");
        //打印消息
        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), StandardCharsets.UTF_8);
            System.out.println(" [x] Received '" + message + "'");
        };
        

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