RabbitMQ消息模型之发布订阅Publish-Subscribe

发布订阅模型 Publish/Subscribe

发布订阅模型也称为广播模型，交换机类型需要指定为Fanout，正如从名称中猜到的那样，它是将接收到的所有消息广播到它知道的所有队列中。每个消费者都监听自己的队列，所以同一个消息，会被所有的消费者共同消费。Fanout 这种交换类型并不能给我们带来很大的灵活性，它只能进行无意识的广播。

在广播模式下，消息发送流程是这样的：

可以有多个消费者。
每个消费者有自己的Queue。
每个队列都要绑定到Exchange。
生产者发送的消息，只能发送到交换机，交换机来决定要发给哪个队列，生产者无法决定。
交换机把消息发送给绑定过的所有队列。
队列的消费者都能拿到消息。实现一条消息被多个消费者消费。

创建生产者

public class MyProducer {@Testpublic void test() throws Exception {// Fanout模式不需要指定队列String queue = "";// 交换机String exchange = "logs";// 创建工厂ConnectionFactory factory = new ConnectionFactory();factory.setVirtualHost("/");factory.setHost("xuewei.world");factory.setUsername("xuewei");factory.setPassword("123456");factory.setPort(5672);// 创建连接和通道Connection connection = factory.newConnection();Channel channel = connection.createChannel();// 声明交换机channel.exchangeDeclare(exchange, "fanout");for (int i = 0; i < 3; i++) {// 发布消息channel.basicPublish(exchange, queue, null, ("DEBUG LOG -> " + i).getBytes());channel.basicPublish(exchange, queue, null, ("INFO LOG -> " + i).getBytes());channel.basicPublish(exchange, queue, null, ("WARN LOG -> " + i).getBytes());channel.basicPublish(exchange, queue, null, ("ERROR LOG -> " + i).getBytes());}}
}

创建消费者1

public class MyConsumer1 {public static void main(String[] args) throws Exception {// 指定交换机String exchange = "logs";// 创建工厂ConnectionFactory factory = new ConnectionFactory();factory.setVirtualHost("/");factory.setHost("xuewei.world");factory.setUsername("xuewei");factory.setPassword("123456");factory.setPort(5672);// 创建连接和通道Connection connection = factory.newConnection();Channel channel = connection.createChannel();//绑定交换机channel.exchangeDeclare("logs", "fanout");//创建临时队列String queue = channel.queueDeclare().getQueue();//将临时队列绑定exchangechannel.queueBind(queue, "logs", "");//处理消息channel.basicConsume(queue, true, new DefaultConsumer(channel) {@Overridepublic void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {System.out.println("消费者1: " + new String(body));// TODO 业务处理}});}
}

创建消费者2

public class MyConsumer2 {public static void main(String[] args) throws Exception {// 指定交换机String exchange = "logs";// 创建工厂ConnectionFactory factory = new ConnectionFactory();factory.setVirtualHost("/");factory.setHost("xuewei.world");factory.setUsername("xuewei");factory.setPassword("123456");factory.setPort(5672);// 创建连接和通道Connection connection = factory.newConnection();Channel channel = connection.createChannel();//绑定交换机channel.exchangeDeclare("logs", "fanout");//创建临时队列String queue = channel.queueDeclare().getQueue();//将临时队列绑定exchangechannel.queueBind(queue, "logs", "");//处理消息channel.basicConsume(queue, true, new DefaultConsumer(channel) {@Overridepublic void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {System.out.println("消费者2: " + new String(body));}});}
}