07-RabbitMQ核心API-Direct Exchange

Direct Exchange

简介

所有发送到direct exchange 的消息被转发到Routekey中指定的Queue

注意: Direct模式可以使用RabbitMQ自带的Exchange(default exchange), 所以不需要将Exchange进行任何Binding操作, 消息传递时RouteKey必须完全匹配才会被队列接收, 否则该消息会被丢弃

代码实现

RabbitMQHelper

代码语言：javascript复制

package com.dance.redis.mq.rabbit;

import com.rabbitmq.client.*;

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

public class RabbitMQHelper {

    private static final String HOST = "192.168.247.142";
    private static final Integer PORT = 5672;
    private static final String VH = "/";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "123456";
    private static final Boolean ARE = true;
    private static final Integer NRI = 3000;

    public static final String EXCHANGE_TYPE_DIRECT = "direct";
    public static final String EXCHANGE_TYPE_TOPIC = "topic";
    public static final String EXCHANGE_TYPE_FANOUT = "fanout";
    public static final String EXCHANGE_TYPE_HEADERS = "headers";

    private static Connection connection = null;

    public static Channel getChannel() throws IOException, TimeoutException {
        if (null == connection) {
            // 创建连接工厂
            ConnectionFactory connectionFactory = new ConnectionFactory();
            connectionFactory.setHost(HOST);
            connectionFactory.setPort(PORT);
            connectionFactory.setVirtualHost(VH);
            connectionFactory.setUsername(USERNAME);
            connectionFactory.setPassword(PASSWORD);
            connectionFactory.setAutomaticRecoveryEnabled(ARE);
            connectionFactory.setNetworkRecoveryInterval(NRI);
            connection = connectionFactory.newConnection();
        }
        return connection.createChannel();
    }

    public static AMQP.Exchange.DeclareOk exchangeDeclare(Channel channel, String exchangeName, String exchangeType) throws IOException {
        return channel.exchangeDeclare(exchangeName, exchangeType, true, false, false, null);
    }
    public static AMQP.Queue.DeclareOk queueDeclare(Channel channel, String queueName) throws IOException {
        return channel.queueDeclare(queueName, false, false, false, null);
    }

    public static void closeConnection() throws IOException {
        connection.close();
    }

    public static Consumer buildConsumer(Channel channel){
        return new DefaultConsumer(channel) {
            @Override
            public void handleDelivery(String consumerTag,
                                       Envelope envelope,
                                       AMQP.BasicProperties properties,
                                       byte[] body)
            throws IOException {
                System.out.println("recvive message:"   new String(body));
                try {
                    TimeUnit.SECONDS.sleep(1);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                channel.basicAck(envelope.getDeliveryTag(), false);
            }
        };
    }

}

创建这个帮助类, 是为了减少一些通用代码的编写, 后续也会使用

消费者

代码语言：javascript复制

package com.dance.redis.mq.rabbit.direct;

import com.dance.redis.mq.rabbit.RabbitMQHelper;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Consumer;

import java.util.concurrent.TimeUnit;
 
public class RabbitMQ4DirectExchangeConsumer {
 
    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQHelper.getChannel();
        String exchangeName = "test_direct_exchange";
        String queueName = "test_direct_queue";
        String routingKey = "test_direct_routingKey";
        RabbitMQHelper.exchangeDeclare(channel,exchangeName,RabbitMQHelper.EXCHANGE_TYPE_DIRECT);
        RabbitMQHelper.queueDeclare(channel,queueName);
        channel.queueBind(queueName, exchangeName, routingKey);
        channel.basicQos(64);//设置客户端最多接收未被ack的消息个数
        Consumer consumer = RabbitMQHelper.buildConsumer(channel);
        channel.basicConsume(queueName, consumer);
        //等待回调函数执行完毕之后，关闭资源。
        TimeUnit.SECONDS.sleep(50);
        channel.close();
        RabbitMQHelper.closeConnection();
    }
}

生产者

代码语言：javascript复制

package com.dance.redis.mq.rabbit.direct;

import com.dance.redis.mq.rabbit.RabbitMQHelper;
import com.rabbitmq.client.Channel;
 
public class RabbitMQ4DirectExchangeProducer {
 
    
    public static void main(String[] args) throws Exception {
        Channel channel = RabbitMQHelper.getChannel();
        String exchangeName = "test_direct_exchange";
        String routingKey = "test_direct_routingKey";
        String msg = "Hello World RabbitMQ 4  Direct Exchange Message ... ";
        channel.basicPublish(exchangeName, routingKey , null , msg.getBytes());
    }
    
}

测试

先启动消费者

然后启动生产者

查看消费者

已经收到了生产者的消息

rabbitmq

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