(四) RabbitMQ实战教程(面向Java开发人员)之@RabbitListener消息消费

使用RabbitListener注解进行消息消费

在前一篇博客中我们往MessageListenerContainer设置了MessageListener进行消息的消费，本篇博客将介绍一种更为简单的消息消费方式:使用@RabbitListener注解方式。使用RabbitListener进行消息的消费步骤如下

1.在启动类上添加@EnableRabbit注解
2.在Spring容器中托管一个RabbitListenerContainerFactory，默认实现类SimpleRabbitListenerContainerFactory
3.编写一个消息处理器类托管到Spring容器中，并使用@RabbitListener注解标注该类为RabbitMQ的消息处理类
4.使用@RabbitHandler注解标注在方法上，表示当有收到消息的时候，就交给带有@RabbitHandler的方法处理，具体找哪个方法需要根据MessageConverter转换后的对象类型决定

本系列博客源码GIT地址:https://github.com/RobertoHuang/RGP-RABBITMQ.git

1.创建生产者配置类

@Configuration
public class SpringAMQPProducerConfig {
    @Bean
    public org.springframework.amqp.rabbit.connection.ConnectionFactory connectionFactory() {
        com.rabbitmq.client.ConnectionFactory connectionFactory = new com.rabbitmq.client.ConnectionFactory();

        connectionFactory.setHost("192.168.56.128");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");
        connectionFactory.setUsername("roberto");
        connectionFactory.setPassword("roberto");

        connectionFactory.setAutomaticRecoveryEnabled(true);
        connectionFactory.setNetworkRecoveryInterval(10000);

        Map connectionFactoryPropertiesMap = new HashMap();
        connectionFactoryPropertiesMap.put("principal", "RobertoHuang");
        connectionFactoryPropertiesMap.put("description", "RGP订单系统V2.0");
        connectionFactoryPropertiesMap.put("emailAddress", "[email protected]");
        connectionFactory.setClientProperties(connectionFactoryPropertiesMap);

        CachingConnectionFactory cachingConnectionFactory = new CachingConnectionFactory(connectionFactory);
        return cachingConnectionFactory;
    }

    @Bean
    public RabbitAdmin rabbitAdmin(org.springframework.amqp.rabbit.connection.ConnectionFactory connectionFactory) {
        return new RabbitAdmin(connectionFactory);
    }

    @Bean
    public RabbitTemplate rabbitTemplate(org.springframework.amqp.rabbit.connection.ConnectionFactory connectionFactory) {
        return new RabbitTemplate(connectionFactory);
    }
}

2.创建生产者启动类

@ComponentScan(basePackages = "roberto.growth.process.rabbitmq.spring.amqp.annotation.producer")
public class ProducerApplication {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(ProducerApplication.class);
        RabbitAdmin rabbitAdmin = context.getBean(RabbitAdmin.class);
        RabbitTemplate rabbitTemplate = context.getBean(RabbitTemplate.class);

        rabbitAdmin.declareExchange(new DirectExchange("roberto.order", true, false, new HashMap<>()));

        MessageProperties messageProperties = new MessageProperties();
        messageProperties.setDeliveryMode(MessageDeliveryMode.PERSISTENT);
        messageProperties.setContentType("UTF-8");
        Message message = new Message("订单信息".getBytes(), messageProperties);
        rabbitTemplate.send("roberto.order", "", message);
    }
}

3.创建消费者配置类 将RabbitListenerContainerFactory交由Spring托管

@Configuration
public class SpringAMQPConsumerConfig {
    @Bean
    public ConnectionFactory connectionFactory() {
        com.rabbitmq.client.ConnectionFactory connectionFactory = new com.rabbitmq.client.ConnectionFactory();

        connectionFactory.setHost("192.168.56.128");
        connectionFactory.setPort(5672);
        connectionFactory.setVirtualHost("/");
        connectionFactory.setUsername("roberto");
        connectionFactory.setPassword("roberto");

        connectionFactory.setAutomaticRecoveryEnabled(true);
        connectionFactory.setNetworkRecoveryInterval(10000);

        Map connectionFactoryPropertiesMap = new HashMap();
        connectionFactoryPropertiesMap.put("principal", "RobertoHuang");
        connectionFactoryPropertiesMap.put("description", "RGP订单系统V2.0");
        connectionFactoryPropertiesMap.put("emailAddress", "[email protected]");
        connectionFactory.setClientProperties(connectionFactoryPropertiesMap);

        CachingConnectionFactory cachingConnectionFactory = new CachingConnectionFactory(connectionFactory);
        return cachingConnectionFactory;
    }

    @Bean
    public RabbitAdmin rabbitAdmin(ConnectionFactory connectionFactory) {
        return new RabbitAdmin(connectionFactory);
    }

    @Bean
    public RabbitListenerContainerFactory rabbitListenerContainerFactory(ConnectionFactory connectionFactory) {
        SimpleRabbitListenerContainerFactory simpleRabbitListenerContainerFactory = new SimpleRabbitListenerContainerFactory();
        simpleRabbitListenerContainerFactory.setConnectionFactory(connectionFactory);

        // 设置消费者线程数
        simpleRabbitListenerContainerFactory.setConcurrentConsumers(5);
        // 设置最大消费者线程数
        simpleRabbitListenerContainerFactory.setMaxConcurrentConsumers(10);

        // 设置消费者标签
        simpleRabbitListenerContainerFactory.setConsumerTagStrategy(new ConsumerTagStrategy() {
            @Override
            public String createConsumerTag(String s) {
                return "RGP订单系统ADD处理逻辑消费者";
            }
        });

        return simpleRabbitListenerContainerFactory;
    }
}

4.自定义消费者消息处理器类 在消息处理器类中使用@RabbitListener注解声明该类为RabbitMQ消息处理器类，并在bindings属性中声明了队列和交换机已经它们之间的绑定关系(监听roberto.order.add队列)，使用@RabbitHandler注解声明具体消息处理方法

@Component
@RabbitListener(bindings = {@QueueBinding(value = @Queue(value = "roberto.order.add", durable = "true", autoDelete = "false", exclusive = "false"), exchange = @Exchange(name = "roberto.order"))})
public class SpringAMQPMessageHandle {
    @RabbitHandler
    public void add(byte[] body) {
        System.out.println("----------byte[]方法进行处理----------");
        try {
            System.out.println(new String(body, "UTF-8"));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
    }
}

5.创建消费者启动类 添加@EnableRabbit注解

@EnableRabbit
@ComponentScan(basePackages = "roberto.growth.process.rabbitmq.spring.amqp.annotation.consumer")
public class ConsumerApplication {
    public static void main(String[] args) {
        new AnnotationConfigApplicationContext(ConsumerApplication.class);
    }
}

6.依次启动消息消费者和生产者 控制台输出如下

----------byte[]方法进行处理----------
订单信息