Java消息隊列RabbitMQ之消息模式詳解

更新時間：2023年07月31日 09:50:07 作者：迷鹿小女子

這篇文章主要介紹了Java消息隊列RabbitMQ之消息模式詳解,RabbitMQ提供了一種qos(服務(wù)質(zhì)量保證)功能,即在非自動確認消息的前提下,如果一定數(shù)目的消息(通過基于Consumer或者Channel設(shè)置Qos的值)未被確認前,不進行消費新的消息,需要的朋友可以參考下

消費端限流

什么是消費端的限流？

假設(shè)一個場景，首先，我們RabbitMQ服務(wù)器有上萬條未處理的消息，我們隨便打開一個消費者客戶端，會出現(xiàn)下面情況：巨量的消息瞬間全部推送過來，但是我們單個客戶端無法同時處理這么多數(shù)據(jù)！

消費端限流RabbitMQ提供的解決方案

RabbitMQ提供了一種qos（服務(wù)質(zhì)量保證）功能，即在非自動確認消息的前提下，如果一定數(shù)目的消息（通過基于Consmer或者Channel設(shè)置Qos的值）未被確認前，不進行消費新的消息

Void BasicQos(uint prefetchSize, ushort prefetchCount, bool global);

prefetchSize：0 不限制消息大小

prefetchSize：會告訴RabbitMQ不要同時給一個消費者推送多于N個消息，即一旦有N個消息還沒有ack，則該Consmer將block（阻塞）掉，直到有消息ack

Global：tre\false是否將上面設(shè)置應(yīng)用于Channel；簡單來說，就是上面限制是Channel級別的還是Consmer級

注意：

prefetchSize和global這兩項，RabbitMQ沒有實現(xiàn)，暫且不研究；

prefetch_cont在no_ask=false的情況下生效，即在自動應(yīng)答的情況下，這兩個值是不生效的；

自定義消費端代碼

package com.xieminglu.rabbitmqapi.limit;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import java.io.IOException;
public class MyConsumer extends DefaultConsumer {
    private Channel channel ;
    public MyConsumer(Channel channel) {
        super(channel);
        this.channel = channel;
    }
    @Override
    public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
        System.err.println("-----------consume message----------");
        System.err.println("consumerTag: " + consumerTag);
        System.err.println("envelope: " + envelope);
        System.err.println("properties: " + properties);
        System.err.println("body: " + new String(body));
        channel.basicAck(envelope.getDeliveryTag(), false);
    }
}

消費端代碼

package com.xieminglu.rabbitmqapi.limit;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Consumer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");
        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();
        String exchangeName = "test_qos_exchange";
        String queueName = "test_qos_queue";
        String routingKey = "qos.#";
        channel.exchangeDeclare(exchangeName, "topic", true, false, null);
        channel.queueDeclare(queueName, true, false, false, null);
        channel.queueBind(queueName, exchangeName, routingKey);
        //1 限流方式  第一件事就是 autoAck設(shè)置為 false
        channel.basicQos(0, 1, false);
        channel.basicConsume(queueName, false, new MyConsumer(channel));
    }
}

提供方代碼

package com.xieminglu.rabbitmqapi.limit;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Producer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");
        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();
        String exchange = "test_qos_exchange";
        String routingKey = "qos.save";
        String msg = "Hello RabbitMQ QOS Message";
        for(int i =0; i<5; i ++){
            channel.basicPublish(exchange, routingKey, true, null, msg.getBytes());
        }
    }
}

消息的ACK與重回隊列

消費端手工ACK與NACK

消費端進行消費的時候，如果由于業(yè)務(wù)異常我們可以進行日志的記錄，然后進行補償

如果由于服務(wù)器宕機等嚴重問題，那么我們就需要手工進行ACK，保障消費端消費成功！

消費端的重回隊列

消費端重回隊列是為了對沒有處理成功的消息，把消息重新回遞給Broker！

一般我們在實際應(yīng)用中，都會關(guān)閉重回隊列，也就是設(shè)置為False；因為重回隊列消息有很大概率依然會處理失?。?/p>

自定義消費者代碼

package com.xieminglu.rabbitmqapi.ack;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import java.io.IOException;
public class MyConsumer extends DefaultConsumer {
    private Channel channel ;
    public MyConsumer(Channel channel) {
        super(channel);
        this.channel = channel;
    }
    @Override
    public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
        System.err.println("-----------consume message----------");
        System.err.println("body: " + new String(body));
        try {
            Thread.sleep(2000);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        if((Integer)properties.getHeaders().get("num") == 0) {
//            手動簽收，重回隊列
            channel.basicNack(envelope.getDeliveryTag(), false, true);
        } else {
            channel.basicAck(envelope.getDeliveryTag(), false);
        }
    }
}

消費者代碼

package com.xieminglu.rabbitmqapi.ack;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Consumer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");
        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();
        String exchangeName = "test_ack_exchange";
        String queueName = "test_ack_queue";
        String routingKey = "ack.#";
        channel.exchangeDeclare(exchangeName, "topic", true, false, null);
        channel.queueDeclare(queueName, true, false, false, null);
        channel.queueBind(queueName, exchangeName, routingKey);
        // 手工簽收 必須要關(guān)閉 autoAck = false
        channel.basicConsume(queueName, false, new MyConsumer(channel));
    }
}

生產(chǎn)者代碼

package com.xieminglu.rabbitmqapi.ack;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.util.HashMap;
import java.util.Map;
public class Producer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");
        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();
        String exchange = "test_ack_exchange";
        String routingKey = "ack.save";
        for(int i =0; i<5; i ++){
            Map<String, Object> headers = new HashMap<String, Object>();
            headers.put("num", i);
            AMQP.BasicProperties properties = new AMQP.BasicProperties.Builder()
                    .deliveryMode(2)
                    .contentEncoding("UTF-8")
                    .headers(headers)
                    .build();
            String msg = "Hello RabbitMQ ACK Message " + i;
            channel.basicPublish(exchange, routingKey, true, properties, msg.getBytes());
        }
    }
}

TTL消息

TTL是Time To Live的縮寫，也就是生存時間

RabbitMQ支持消息的過期時間，在消息發(fā)送時可以進行指定
RabbitMQ支持隊列的過期時間，從消息入隊列開始計算，只要超過了隊列的超時時間配置，那么消息自動的清除

純控制臺操作（演示TTL隊列消息特點）針對隊列，只要是這個隊列的消息，就只有這么長的存活時間

注意：主要針對消息設(shè)置，跟交換機、隊列、消費者設(shè)置毫無關(guān)系

消費端代碼

package com.xieminglu.rabbitmqapi.ttl;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;
import java.util.Map;
public class Consumer {
    public static void main(String[] args) throws Exception {
        //1 創(chuàng)建一個ConnectionFactory, 并進行配置
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");
        //2 通過連接工廠創(chuàng)建連接
        Connection connection = connectionFactory.newConnection();
        //3 通過connection創(chuàng)建一個Channel
        Channel channel = connection.createChannel();
        //4 聲明（創(chuàng)建）一個隊列
        String queueName = "test001";
        channel.queueDeclare(queueName, true, false, false, null);
        //5 創(chuàng)建消費者
        QueueingConsumer queueingConsumer = new QueueingConsumer(channel);
        //6 設(shè)置Channel
        channel.basicConsume(queueName, true, queueingConsumer);
        while(true){
            //7 獲取消息
            QueueingConsumer.Delivery delivery = queueingConsumer.nextDelivery();
            String msg = new String(delivery.getBody());
            System.err.println("消費端: " + msg);
            Map<String, Object> headers = delivery.getProperties().getHeaders();
            System.err.println("headers get my1 value: " + headers.get("my1"));
            //Envelope envelope = delivery.getEnvelope();
        }
    }
}

生產(chǎn)端代碼

package com.xieminglu.rabbitmqapi.ttl;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.util.HashMap;
import java.util.Map;
public class Procuder {
    public static void main(String[] args) throws Exception {
        //1 創(chuàng)建一個ConnectionFactory, 并進行配置
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");
        //2 通過連接工廠創(chuàng)建連接
        Connection connection = connectionFactory.newConnection();
        //3 通過connection創(chuàng)建一個Channel
        Channel channel = connection.createChannel();
        Map<String, Object> headers = new HashMap<>();
        headers.put("my1", "111");
        headers.put("my2", "222");
        AMQP.BasicProperties properties = new AMQP.BasicProperties.Builder()
                .deliveryMode(2)
                .contentEncoding("UTF-8")
                .expiration("10000")
                .headers(headers)
                .build();
        //4 通過Channel發(fā)送數(shù)據(jù)
        for(int i=0; i < 5; i++){
            String msg = "Hello RabbitMQ!";
            //1 exchange   2 routingKey
            channel.basicPublish("", "test001", properties, msg.getBytes());
        }
        //5 記得要關(guān)閉相關(guān)的連接
        channel.close();
        connection.close();
    }
}

死信隊列

利用DLX，當(dāng)消息在一個隊列中變成死信（dead message）之后，它能被重新pblish到另一個Exchange，這個Exchange就是DLX

消息變成死信有以下幾種情況

消息被拒絕（basic.reject/basic.nack）并且reqee=false 消息TTL過期隊列達到最大長度
死信隊列的特點 DLX也是一個正常的Exchange，和一般的Exchange沒有區(qū)別，它能在任何的隊列上被指定，實際上就是設(shè)置某個隊列的屬性；
當(dāng)這個隊列中有死信時，RabbitMQ就會自動的將這個消息重新發(fā)布到設(shè)置的Exchange上去，進而被路由到另一個隊列；
可以監(jiān)聽這個隊列中消息做相應(yīng)的處理，這個特性可以彌補RabbitMQ3.0以前支持的immediate參數(shù)的功能；

死信隊列設(shè)置

首先需要設(shè)置死信隊列的Exchange和Qee，然后進行綁定：

Exchange：dlx.exchange
Qee：dlx.qee
RotingKey：#

然后我們進行正常聲明交換機、隊列、綁定，只不過我們需要在隊列加上一個參數(shù)即可：

Argments.pt(“x-dead-letter-exchange”,”dlx.exchange”)；

這樣消息在過期、reqee、隊列在達到最大長度時，消息就可以直接路由到死信隊列！

在這里插入圖片描述

自定義消費端

package com.xieminglu.rabbitmqapi.dlx;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import java.io.IOException;
public class MyConsumer extends DefaultConsumer {
    public MyConsumer(Channel channel) {
        super(channel);
    }
    @Override
    public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
        System.err.println("-----------consume message----------");
        System.err.println("consumerTag: " + consumerTag);
        System.err.println("envelope: " + envelope);
        System.err.println("properties: " + properties);
        System.err.println("body: " + new String(body));
    }
}

消費端代碼

package com.xieminglu.rabbitmqapi.dlx;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.util.HashMap;
import java.util.Map;
public class Consumer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");
        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();
        // 這就是一個普通的交換機 和 隊列 以及路由
        String exchangeName = "test_dlx_exchange";
        String routingKey = "dlx.#";
        String queueName = "test_dlx_queue";
        channel.exchangeDeclare(exchangeName, "topic", true, false, null);
        Map<String, Object> agruments = new HashMap<String, Object>();
        agruments.put("x-dead-letter-exchange", "dlx.exchange");
        //這個agruments屬性，要設(shè)置到聲明隊列上
        channel.queueDeclare(queueName, true, false, false, agruments);
        channel.queueBind(queueName, exchangeName, routingKey);
        //要進行死信隊列的聲明:
        channel.exchangeDeclare("dlx.exchange", "topic", true, false, null);
        channel.queueDeclare("dlx.queue", true, false, false, null);
        channel.queueBind("dlx.queue", "dlx.exchange", "#");
        channel.basicConsume(queueName, true, new MyConsumer(channel));
    }
}

生產(chǎn)端代碼

package com.xieminglu.rabbitmqapi.dlx;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
public class Producer {
    public static void main(String[] args) throws Exception {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost("192.168.248.134");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");
        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();
        String exchange = "test_dlx_exchange";
        String routingKey = "dlx.save";
        String msg = "Hello RabbitMQ DLX Message";
        for(int i =0; i<1; i ++){
            AMQP.BasicProperties properties = new AMQP.BasicProperties.Builder()
                    .deliveryMode(2)
                    .contentEncoding("UTF-8")
                    .expiration("10000")//設(shè)置過期時間
                    .build();
            channel.basicPublish(exchange, routingKey, true, properties, msg.getBytes());
        }
    }
}

本節(jié)學(xué)習(xí)了RabbitMQ的高級特性，首先介紹了互聯(lián)網(wǎng)大廠在實際使用中是如何保障100%的消息投遞成功和冪等性的，以及對RabbitMQ的確認消息、返回消息、ACK與重回隊列、消息的限流，以及對超時時間、死信隊列的使用

到此這篇關(guān)于Java消息隊列RabbitMQ之消息模式詳解的文章就介紹到這了,更多相關(guān)RabbitMQ之消息模式內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家！

您可能感興趣的文章: