rabbitmq入门（三）Routing(Direct交换机)

骑猪看日落 2023-06-15 15:23 46阅读 0赞

### 文章目录 ###

*   *  什么是Routing（路由模式）
     *  代码实现如下
     *  下一章

![在这里插入图片描述][20191122233725117.png]

## 什么是Routing（路由模式） ##

rabbitmq第四种队列 Routing 是在Publish/Subscribe上面多了一个路由策略  
交换机由Fanout exchange（扇型交换机）变为Direct exchange（直连交换机）  
交换机在发送消息的时候会绑定一个 routing key，队列也需要绑定 routing key，一个队列可以绑定多个routing key，只有routing key相同才能接受到消息

## 代码实现如下 ##

生产者  
RountingProducer

//生成者 交换机类型为direct类型
    public class RountingProducer { 
    
        //交换机名称
        private static final String DESTINATION_NAME = "direct_destination";
        //routing key
        private static final String ROUTING_KEY = "sms";
        private static final String ROUTING_KEY1 = "email";
    
        public static void main(String[] args) throws Exception{ 
            //1.建立连接
            Connection connection = MQConnectionUtils.newConnection();
            //2. 创建通道
            Channel channel = connection.createChannel();
            //3.生产者绑定交换机 参数1. 交换机名称 2.交换机类型 direct
            channel.exchangeDeclare(DESTINATION_NAME, "direct");
            //4. 创建消息
            String msg = "fanout_destination" + "发送消息";
            //5.发送消息 参数1为交换机名 2 为这里routingKey 3.为消息基本属性 4.为消息
            //这里绑定routing key为 severity
            channel.basicPublish(DESTINATION_NAME,ROUTING_KEY1,null, msg.getBytes());
            //6. 关闭通道和连接
            channel.close();
            connection.close();
        }
    }

邮件消费者

public class CustomerEmailDirect { 
        //队列名称
        private static final String EMAIL_QUEUE = "email_direct";
        //交换机名称
        private static final String DESTINATION_NAME = "direct_destination";
    
        //routing key
        private static final String ROUTING_KEY = "email";
        private static final String ROUTING_KEY1 = "sms";
    
        public static void main(String[] args) throws Exception{ 
            System.out.println("邮件消费者启动");
            //1.建立连接
            Connection connection = MQConnectionUtils.newConnection();
            //2. 创建通道
            Channel channel = connection.createChannel();
            // 3.声明消费队列
            channel.queueDeclare(EMAIL_QUEUE, false, false, false, null);
            //4.消费者绑定交换机 参数1 队列 参数2交换机 参数3 routingKey
            channel.queueBind(EMAIL_QUEUE, DESTINATION_NAME, ROUTING_KEY);
            channel.queueBind(EMAIL_QUEUE, DESTINATION_NAME, ROUTING_KEY1);
            //5.消费者监听消息
            DefaultConsumer defaultConsumer = new DefaultConsumer(channel){ 
                @Override
                public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { 
                    String msg = new String(body, "UTF-8");
                    System.out.println("邮件消费者获取消息" + msg);
                }
            };
            channel.basicConsume(EMAIL_QUEUE, true, defaultConsumer);
    
        }
    }

短信消费者 CustomerSmsDirect

public class CustomerSmsDirect { 
        //队列名称
        private static final String SMS_QUEUE = "msm_direct";
        //交换机名称
        private static final String DESTINATION_NAME = "direct_destination";
        //routing key
        private static final String ROUTING_KEY = "sms";
    
        public static void main(String[] args) throws Exception{ 
            System.out.println("短信消费者启动");
            //1.建立连接
            Connection connection = MQConnectionUtils.newConnection();
            //2. 创建通道
            Channel channel = connection.createChannel();
            // 3.声明消费队列
            channel.queueDeclare(SMS_QUEUE, false, false, false, null);
            //4.消费者绑定交换机 参数1 队列 参数2交换机 参数3 routingKey
            channel.queueBind(SMS_QUEUE, DESTINATION_NAME, ROUTING_KEY);
            //5.消费者监听消息
            DefaultConsumer defaultConsumer = new DefaultConsumer(channel){ 
                @Override
                public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException { 
                    String msg = new String(body, "UTF-8");
                    System.out.println("短信消费者获取消息" + msg);
                }
            };
            channel.basicConsume(SMS_QUEUE, true, defaultConsumer);
    
        }
    }

> 上面代码我们可以看到 CustomerEmailDirect即邮件队列是绑定了两个routing key,也就是如果交换机绑定的  
> routing key为sms，则两个队列都可以接受到消息，如果交换机绑定的routing key为email，则仅邮件队列能接受到消息  
> 如果交换机绑定的routing key没有队列绑定，则消息也是会直接丢失的

## 下一章 ##

[rabbitmq入门（四）Topics主题模式][rabbitmq_Topics]

[20191122233725117.png]: https://img-blog.csdnimg.cn/20191122233725117.png
[rabbitmq_Topics]: https://blog.csdn.net/qq_42651904/article/details/103210944