RabbitMQ学习系列（五）：routing路由模式和Topic主题模式

（一）routing路由模式

在前面一篇博客中讲到了exchange的类型，其中direct类型的exchange就是用于routing路由模式。direct类型的交换机是指：交换机和队列绑定时会设置路由键（routingkey），当消息从生产者发送给交换机时也会发送一个路由键。只有当这两个路由键相同时，交换机才会把消息发送给队列。

如上图所示，当生产者发送消息的路由键为error时，两个队列均可以收到消息；当生产者发送消息的路由键为info或warning时，只有第二个队列可收到消息。

（二）路由模式实践

2.1 工具类

工具类和之前都一样，不做介绍了

public class ConnectionUtil {public static Connection getConnection() throws IOException, TimeoutException {//定义一个连接工厂ConnectionFactory factory=new ConnectionFactory();//设置服务地址factory.setHost("127.0.0.1");//设置AMQP端口factory.setPort(5672);//设置VHOSTSfactory.setVirtualHost("/vhosts_sdxb");//设置用户名factory.setUsername("user_sdxb");factory.setPassword("123456");return factory.newConnection();}
}

2.2 生产者

与前面几种模式不同的地方已经通过注解标出，其中交换机类型选择成direct，并且按需要设置路由键

public class Sent {private static final String EXCHANGENAME="routing_exchange";public static void main(String[] args) throws IOException, TimeoutException {Connection connection = ConnectionUtil.getConnection();Channel channel = connection.createChannel();//交换机类型选择directchannel.exchangeDeclare(EXCHANGENAME,"direct");String msg="hello world";//设置路由键（routingkey）String routingkey="error";channel.basicPublish(EXCHANGENAME,routingkey,null,msg.getBytes());channel.close();connection.close();}
}

2.3 消费者一

在队列绑定时设置队列的路由键

public class Receive1 {private static final String QUEUENAME="routing_queue1";private static final String EXCHANGENAME="routing_exchange";public static void main(String[] args) throws IOException, TimeoutException {Connection connection = ConnectionUtil.getConnection();final Channel channel = connection.createChannel();channel.queueDeclare(QUEUENAME, false, false, false, null);//在队列绑定时设置路由键channel.queueBind(QUEUENAME, EXCHANGENAME, "error");Consumer consumer = new DefaultConsumer(channel) {@Overridepublic void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {String msg = new String(body, "utf-8");System.out.println("receive:" + msg);}};//监听队列channel.basicConsume(QUEUENAME, true, consumer);}
}

2.4 消费者二

在第二个消费者的队列中设置多个路由键

public class Receive2 {private static final String QUEUENAME="routing_queue2";private static final String EXCHANGENAME="routing_exchange";public static void main(String[] args) throws IOException, TimeoutException {Connection connection = ConnectionUtil.getConnection();final Channel channel = connection.createChannel();channel.queueDeclare(QUEUENAME, false, false, false, null);//在队列绑定时设置多个路由键channel.queueBind(QUEUENAME, EXCHANGENAME, "error");channel.queueBind(QUEUENAME, EXCHANGENAME, "info");channel.queueBind(QUEUENAME, EXCHANGENAME, "warning");Consumer consumer = new DefaultConsumer(channel) {@Overridepublic void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {String msg = new String(body, "utf-8");System.out.println("receive:" + msg);}};//监听队列channel.basicConsume(QUEUENAME, true, consumer);}
}

2.5运行结果

当路由键为error时，两个消费者均输出消息。当路由键为info或warning时，只有第二个消费者输出消息。

（三）Topic主题模式

Topic主题模式和routing路由模式类似，只不过这里的交换机使用的是topic类型，topic类型的交换机和direct的不同就在于topic可以匹配通配符。*代表匹配一个元素，#代表匹配一个或多个元素

以上图为例，Q1队列的路由键为*.orange.*,Q2队列的路由键为*.*.rabbit和lazy.#，当消息的路由键为quick.orange.rabbit时，两个队列均能收到，当消息的路由键为lazy.orange.male.rabbit时，只有Q2队列能收到。

（四）主题模式实践

在routing路由模式的代码基础上修改

4.1 生产者

//交换机类型选择direct
channel.exchangeDeclare(EXCHANGENAME,"topic");
//设置路由键（routingkey）
String routingkey="lazy.brown.fox";

4.2 消费者一

channel.queueBind(QUEUENAME, EXCHANGENAME, "*.orange.*");

4.3 消费者二

channel.queueBind(QUEUENAME, EXCHANGENAME, "*.*.rabbit");
channel.queueBind(QUEUENAME, EXCHANGENAME, "lazy.#");

修改以上几处地方就实现了上述topic模型