RabbitMQ 的自定义消费者使用

之前的文章里面，我都是在消费端的代码里面编写 while 循环，进行 consumer.nextDelivery 方法进行获取下一条消息，然后进行消费处理，这种方式太 low 了，耦合性太高，所以要使用自定义的 consumer 来解耦，这种方式更方便一些，也是在实际工作中最常用的使用方式

下面来看看具体的代码实现， 代码地址：

https://github.com/hmilyos/rabbitmqdemo.git  rabbitmq-api 项目下

如图所示，先来实现我们的自定义消费者

public class MyConsumer extends DefaultConsumer {

    private static final Logger log = LoggerFactory.getLogger(MyConsumer.class);
    
    public MyConsumer(Channel channel) {
        super(channel);
    }

    @Override
    public void handleDelivery(String consumerTag,  //消费者标签
                               Envelope envelope,
                               AMQP.BasicProperties properties,
                               byte[] body) throws IOException {
        log.info("------MyConsumer-----consume message----------");
        log.info("consumerTag: " + consumerTag);
        log.info("envelope: " + envelope);
        log.info("properties: " + properties);
        log.info("body: " + new String(body));
    }
}

接着，重点来了，在声明消费者的代码里面使用刚才的自定义消费者

/**
 * 使用自定义消费者
 */
public class Consumer {

    private static final Logger log = LoggerFactory.getLogger(Consumer.class);
    
    public static final String EXCHANGE_NAME = "test_consumer_exchange";
    public static final String EXCHANGE_TYPE = "topic";
    public static final String ROUTING_KEY_TYPE = "consumer.#";
    public static final String ROUTING_KEY = "consumer.save";
    public static final String QUEUE_NAME = "test_consumer_queue";
    
    public static void main(String[] args) throws IOException, TimeoutException {
        //1 创建ConnectionFactory
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost(RabbitMQCommon.RABBITMQ_HOST);
        connectionFactory.setPort(RabbitMQCommon.RABBITMQ_PORT);
        connectionFactory.setVirtualHost(RabbitMQCommon.RABBITMQ_DEFAULT_VIRTUAL_HOST);
        //2 获取C onnection
        Connection connection = connectionFactory.newConnection();
        //3 通过Connection创建一个新的Channel
        Channel channel = connection.createChannel();
        
        channel.exchangeDeclare(EXCHANGE_NAME, EXCHANGE_TYPE, true, false, null);
        channel.queueDeclare(QUEUE_NAME, true, false, false, null);
        channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, ROUTING_KEY_TYPE);
        
      //使用自定义消费者
        channel.basicConsume(QUEUE_NAME, true, new MyConsumer(channel));
        log.info("消费端启动成功");
    }
}

生产端代码基本不需要修改

public class Procuder {

    private static final Logger log = LoggerFactory.getLogger(Procuder.class);

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost(RabbitMQCommon.RABBITMQ_HOST);
        connectionFactory.setPort(RabbitMQCommon.RABBITMQ_PORT);
        connectionFactory.setVirtualHost(RabbitMQCommon.RABBITMQ_DEFAULT_VIRTUAL_HOST);

        Connection connection = connectionFactory.newConnection();
        Channel channel = connection.createChannel();

        String msg = "Hello RabbitMQ Consumer Message";
        for(int i = 0; i < 5; i ++){
            log.info("生产端发送：{}", msg + i);
            channel.basicPublish(Consumer.EXCHANGE_NAME, Consumer.ROUTING_KEY, true, null, (msg + i).getBytes());
        }
    }
}

先启动消费端，再启动生产端，查看运行结果：注意看消费端的日志，打印出了我们自定义消费者里面的东西了。

image image

至此，简单的使用自定义消费者demo就完成了。