Fanout消息模型

fanout扇出 也称广播

fanout.jpg

广播模式下,消息发送流程是这样的:

  • 可以有多个消费者
  • 每个消费者都有自己的queue队列(临时,消费完断开连接后自动删除)
  • 每个队列都要绑定到exchange交换机
  • 生产者发送的消息,只能发送到交换机,交换机决定来发送给哪个队列,生产者无法决定
  • 交换机把收到的消息发送给每一个队列,实现一条消息被多个消费者消费

生产者

public class Provider {
    @Test
    public void test() throws IOException {
        Connection connection = RabbitMqUtil.getConnection();
        Channel channel = connection.createChannel();
        //通道绑定声明交换机
        channel.exchangeDeclare("logs","fanout");
        //生产消息
        channel.basicPublish("logs","",null,"fanout type message".getBytes());
        RabbitMqUtil.close(channel,connection);
    }
}

注意:Exchange(交换机)只负责转发消息,不具备存储消息的能力,因此如果没有任何队列与Exchange绑定,或者没有符合路由规则的队列,那么消息会丢失!

多消费者

customer1:

public class Customer1 {
    public static void main(String[] args) throws IOException {
        Connection connection = RabbitMqUtil.getConnection();
        Channel channel = connection.createChannel();

        //通道绑定交换机
        channel.exchangeDeclare("logs","fanout");
        //创建临时队列
        String queue = channel.queueDeclare().getQueue();
        //将队列和交换机进行绑定
        channel.queueBind(queue,"logs","");
        //消费消息
        channel.basicConsume(queue,true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("fanout模型 消费者一消费:"+new String(body));
            }
        });

    }
}

customer2:

public class Customer2 {
    public static void main(String[] args) throws IOException {
        Connection connection = RabbitMqUtil.getConnection();
        Channel channel = connection.createChannel();

        //通道绑定交换机
        channel.exchangeDeclare("logs","fanout");
        //创建临时队列
        String queue = channel.queueDeclare().getQueue();
        //将队列和交换机进行绑定
        channel.queueBind(queue,"logs","");
        //消费消息
        channel.basicConsume(queue,true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("fanout模型 消费者二消费:"+new String(body));
            }
        });

    }
}

customer3:

public class Customer3 {
    public static void main(String[] args) throws IOException {
        Connection connection = RabbitMqUtil.getConnection();
        Channel channel = connection.createChannel();

        //通道绑定交换机
        channel.exchangeDeclare("logs","fanout");
        //创建临时队列
        String queue = channel.queueDeclare().getQueue();
        //将队列和交换机进行绑定
        channel.queueBind(queue,"logs","");
        //消费消息
        channel.basicConsume(queue,true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("fanout模型 消费者三消费:"+new String(body));
            }
        });

    }
}

消费者1.jpg

消费者2.jpg

消费者3.jpg

最后修改:2021 年 02 月 05 日 03 : 25 PM
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