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  • RabbitMQ 中的 7 种队列模式,写得太好了!

七种模式介绍与应用场景

简单模式(Hello World)

做最简单的事情,一个生产者对应一个消费者,RabbitMQ相当于一个消息代理,负责将A的消息转发给B

应用场景: 将发送的电子邮件放到消息队列,然后邮件服务在队列中获取邮件并发送给收件人

工作队列模式(Work queues)

在多个消费者之间分配任务(竞争的消费者模式),一个生产者对应多个消费者,一般适用于执行资源密集型任务,单个消费者处理不过来,需要多个消费者进行处理

应用场景: 一个订单的处理需要10s,有多个订单可以同时放到消息队列,然后让多个消费者同时处理,这样就是并行了,而不是单个消费者的串行情况

订阅模式(Publish/Subscribe)

一次向许多消费者发送消息,一个生产者发送的消息会被多个消费者获取,也就是将消息将广播到所有的消费者中。

应用场景: 更新商品库存后需要通知多个缓存和多个数据库,这里的结构应该是:

  • 一个fanout类型交换机扇出两个个消息队列,分别为缓存消息队列、数据库消息队列
  • 一个缓存消息队列对应着多个缓存消费者
  • 一个数据库消息队列对应着多个数据库消费者

路由模式(Routing)

有选择地(Routing key)接收消息,发送消息到交换机并且要指定路由key ,消费者将队列绑定到交换机时需要指定路由key,仅消费指定路由key的消息

应用场景: 如在商品库存中增加了1台iphone12,iphone12促销活动消费者指定routing key为iphone12,只有此促销活动会接收到消息,其它促销活动不关心也不会消费此routing key的消息

主题模式(Topics)

根据主题(Topics)来接收消息,将路由key和某模式进行匹配,此时队列需要绑定在一个模式上,#匹配一个词或多个词,*只匹配一个词。

应用场景: 同上,iphone促销活动可以接收主题为iphone的消息,如iphone12、iphone13等

远程过程调用(RPC)

如果我们需要在远程计算机上运行功能并等待结果就可以使用RPC,具体流程可以看图。应用场景:需要等待接口返回数据,如订单支付

发布者确认(Publisher Confirms)

与发布者进行可靠的发布确认,发布者确认是RabbitMQ扩展,可以实现可靠的发布。在通道上启用发布者确认后,RabbitMQ将异步确认发送者发布的消息,这意味着它们已在服务器端处理。

应用场景: 对于消息可靠性要求较高,比如钱包扣款

代码演示

代码中没有对后面两种模式演示,有兴趣可以自己研究

简单模式

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

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

public class Sender {

    private final static String QUEUE_NAME = "simple_queue";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        // 声明队列
        // queue:队列名
        // durable:是否持久化
        // exclusive:是否排外 即只允许该channel访问该队列 一般等于true的话用于一个队列只能有一个消费者来消费的场景
        // autoDelete:是否自动删除 消费完删除
        // arguments:其他属性
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);

        //消息内容
        String message = "simplest mode message";
        channel.basicPublish("", QUEUE_NAME, null, message.getBytes());
        System.out.println("[x]Sent '" + message + "'");

        //最后关闭通关和连接
        channel.close();
        connection.close();

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

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


public class Receiver {

    private final static String QUEUE_NAME = "simplest_queue";

    public static void main(String[] args) throws IOException, InterruptedException, TimeoutException {
        // 获取连接
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        channel.queueDeclare(QUEUE_NAME, false, false, false, null);

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received '" +
                    delivery.getEnvelope().getRoutingKey() + "':'" + message + "'");
        };
        channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> {
        });
    }
}

工作队列模式

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

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

public class Receiver1 {

    private final static String QUEUE_NAME = "queue_work";

    public static void main(String[] args) throws IOException, InterruptedException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        // 同一时刻服务器只会发送一条消息给消费者
        channel.basicQos(1);

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received '" +
                    delivery.getEnvelope().getRoutingKey() + "':'" + message + "'");
        };
        channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> {
        });

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

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


public class Receiver2 {

    private final static String QUEUE_NAME = "queue_work";

    public static void main(String[] args) throws IOException, InterruptedException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();


        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        // 同一时刻服务器只会发送一条消息给消费者
        channel.basicQos(1);

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received '" +
                    delivery.getEnvelope().getRoutingKey() + "':'" + message + "'");
        };
        channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> {
        });

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

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


public class Sender {

    private final static String QUEUE_NAME = "queue_work";

    public static void main(String[] args) throws IOException, InterruptedException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        // 声明队列
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        for (int i = 0; i < 100; i++) {
            String message = "work mode message" + i;
            channel.basicPublish("", QUEUE_NAME, null, message.getBytes());
            System.out.println("[x] Sent '" + message + "'");
            Thread.sleep(i * 10);
        }

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

发布订阅模式

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

public class Receive1 {

    private static final String EXCHANGE_NAME = "logs";

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


        channel.exchangeDeclare(EXCHANGE_NAME, "fanout");
        String queueName = channel.queueDeclare().getQueue();
        channel.queueBind(queueName, EXCHANGE_NAME, "");

        System.out.println(" [*] Waiting for messages. To exit press CTRL+C");

        // 订阅消息的回调函数
        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received '" + message + "'");
        };

        // 消费者,有消息时出发订阅回调函数
        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
        });
    }
}
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.DeliverCallback;

public class Receive2 {

    private static final String EXCHANGE_NAME = "logs";

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


        channel.exchangeDeclare(EXCHANGE_NAME, "fanout");
        String queueName = channel.queueDeclare().getQueue();
        channel.queueBind(queueName, EXCHANGE_NAME, "");

        System.out.println(" [*] Waiting for messages. To exit press CTRL+C");

        // 订阅消息的回调函数
        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received2 '" + message + "'");
        };

        // 消费者,有消息时出发订阅回调函数
        channel.basicConsume(queueName, true, deliverCallback, consumerTag -> {
        });
    }
}
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

public class Sender {

    private static final String EXCHANGE_NAME = "logs";

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


        channel.exchangeDeclare(EXCHANGE_NAME, "fanout");

        String message = "publish subscribe message";
        channel.basicPublish(EXCHANGE_NAME, "", null, message.getBytes("UTF-8"));
        System.out.println(" [x] Sent '" + message + "'");

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

路由模式

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

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


public class Receiver1 {

    private final static String QUEUE_NAME = "queue_routing";
    private final static String EXCHANGE_NAME = "exchange_direct";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();


        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        // 指定路由的key,接收key和key2
        channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "key");
        channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "key2");

        channel.basicQos(1);

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received '" +
                    delivery.getEnvelope().getRoutingKey() + "':'" + message + "'");
        };
        channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> {
        });
    }

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

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


public class Receiver2 {

    private final static String QUEUE_NAME = "queue_routing2";
    private final static String EXCHANGE_NAME = "exchange_direct";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();


        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        // 仅接收key2
        channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "key2");

        channel.basicQos(1);

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received '" +
                    delivery.getEnvelope().getRoutingKey() + "':'" + message + "'");
        };
        channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> {
        });


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

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


public class Sender {

    private final static String EXCHANGE_NAME = "exchange_direct";
    private final static String EXCHANGE_TYPE = "direct";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        // 交换机声明
        channel.exchangeDeclare(EXCHANGE_NAME, EXCHANGE_TYPE);

        // 只有routingKey相同的才会消费
        String message = "routing mode message";
        channel.basicPublish(EXCHANGE_NAME, "key2", null, message.getBytes());
        System.out.println("[x] Sent '" + message + "'");
// channel.basicPublish(EXCHANGE_NAME, "key", null, message.getBytes());
// System.out.println("[x] Sent '" + message + "'");

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

主题模式

public class Receiver1 {

    private final static String QUEUE_NAME = "queue_topic";
    private final static String EXCHANGE_NAME = "exchange_topic";

    public static void main(String[] args) throws IOException, InterruptedException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        // 可以接收key.1
        channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "key.*");

        channel.basicQos(1);

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received '" +
                    delivery.getEnvelope().getRoutingKey() + "':'" + message + "'");
        };
        channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> {
        });
    }
}
public class Receiver1 {

    private final static String QUEUE_NAME = "queue_topic";
    private final static String EXCHANGE_NAME = "exchange_topic";

    public static void main(String[] args) throws IOException, InterruptedException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        // 可以接收key.1
        channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, "key.*");

        channel.basicQos(1);

        DeliverCallback deliverCallback = (consumerTag, delivery) -> {
            String message = new String(delivery.getBody(), "UTF-8");
            System.out.println(" [x] Received '" +
                    delivery.getEnvelope().getRoutingKey() + "':'" + message + "'");
        };
        channel.basicConsume(QUEUE_NAME, true, deliverCallback, consumerTag -> {
        });
    }
}
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

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


public class Sender {

    private final static String EXCHANGE_NAME = "exchange_topic";
    private final static String EXCHANGE_TYPE = "topic";

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();

        channel.exchangeDeclare(EXCHANGE_NAME, EXCHANGE_TYPE);

        String message = "topics model message with key.1";
        channel.basicPublish(EXCHANGE_NAME, "key.1", null, message.getBytes());
        System.out.println("[x] Sent '" + message + "'");
        String message2 = "topics model message with key.1.2";
        channel.basicPublish(EXCHANGE_NAME, "key.1.2", null, message2.getBytes());
        System.out.println("[x] Sent '" + message2 + "'");

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

四种交换机介绍

1、直连交换机(Direct exchange):

具有路由功能的交换机,绑定到此交换机的时候需要指定一个routing_key,交换机发送消息的时候需要routing_key,会将消息发送道对应的队列

2、扇形交换机(Fanout exchange):

广播消息到所有队列,没有任何处理,速度最快

3、主题交换机(Topic exchange):

在直连交换机基础上增加模式匹配,也就是对routing_key进行模式匹配,*代表一个单词,#代表多个单词

4、首部交换机(Headers exchange):

忽略routing_key,使用Headers信息(一个Hash的数据结构)进行匹配,优势在于可以有更多更灵活的匹配规则

总结

这么多种队列模式中都有其应用场景,大家可以根据应用场景示例中进行选择。

原文链接:https://blog.csdn.net/qq_32828253/article/details/110450249

版权声明:本文为CSDN博主「我思知我在」的原创文章,遵循CC 4.0 BY-SA版权协议,转载请附上原文出处链接及本声明。


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