RabbitMQ中的SimpleMessageListener

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通过上文可以使用rabbitmq了，但是有这样一个特殊需求，想不使用通用的配置，而是该队列使用特殊的配置，那么就可以使用SimpleMessageListener，来自定义消费者。

1.代码实现

可以看到下文两个方法配置了两种应答方式，方法一为手动应答，方法二为自动应答。通过以下方式可以自由的选择想要的配置。

1.手动应答SimpleMessageListener

如正规方式一样，使用手动应答，需要在接收到消息后手动发送ack/nack。核心代码如下：container.setAcknowledgeMode(AcknowledgeMode.MANUAL);

import org.springframework.amqp.core.AcknowledgeMode;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;
import org.springframework.amqp.rabbit.listener.api.ChannelAwareMessageListener;
import org.springframework.amqp.support.ConsumerTagStrategy;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;

import com.alibaba.fastjson.JSONObject;
import com.rabbitmq.client.Channel;
import org.springframework.context.annotation.Configuration;


@Configuration
public class SimpleMessageListener {

    @Bean
    public SimpleMessageListenerContainer messageContainer(ConnectionFactory connectionFactory) {
        SimpleMessageListenerContainer container = new SimpleMessageListenerContainer(connectionFactory);
        // 添加队列 可以添加多个队列
        container.setExposeListenerChannel(true);
        // 设置当前的消费者数量
        // container.setMaxConcurrentConsumers(5);
        container.setConcurrentConsumers(1);
        // 设置确认模式手工确认
        container.setAcknowledgeMode(AcknowledgeMode.MANUAL);
        container.setMessageListener(new ChannelAwareMessageListener() {
            @Override
            public void onMessage(Message message, Channel channel) throws Exception {
                byte[] body = message.getBody();
                System.out.println("1  receive msg : " + JSONObject.parseObject(new String(body)));
                // 确认消息成功消费，删除消息队列中的消息，他跟上面貌似一样
                channel.basicAck(message.getMessageProperties().getDeliveryTag(), true);
            }
        });
        return container;
    }

}

2.自动应答SimpleMessageListener

该方法会直接应答，核心代码如下：container.setAcknowledgeMode(AcknowledgeMode.AUTO);

import org.springframework.amqp.core.AcknowledgeMode;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;
import org.springframework.amqp.rabbit.listener.api.ChannelAwareMessageListener;
import org.springframework.amqp.support.ConsumerTagStrategy;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;

import com.alibaba.fastjson.JSONObject;
import com.rabbitmq.client.Channel;
import org.springframework.context.annotation.Configuration;


@Configuration
public class SimpleMessageListener {

    @Bean
    public SimpleMessageListenerContainer messageContainer2(ConnectionFactory connectionFactory) {
        SimpleMessageListenerContainer container = new SimpleMessageListenerContainer(connectionFactory);
        // 设置当前消费者数量
        container.setConcurrentConsumers(1);
        // 设置最大的消费者数量
        container.setMaxConcurrentConsumers(5);
        // 设置不要重回队列
        container.setDefaultRequeueRejected(false);
        // 设置自动签收
        container.setAcknowledgeMode(AcknowledgeMode.AUTO);
        // 设置消费端tag策略
        container.setConsumerTagStrategy(new ConsumerTagStrategy() {
            @Override
            public String createConsumerTag(String queue) {
                return queue + "_" + System.currentTimeMillis();
            }
        });
        // 设置监听
        container.setMessageListener(new ChannelAwareMessageListener() {
            @Override
            public void onMessage(Message message, Channel channel) throws Exception {
                // 消息处理
                String msg = new String(message.getBody(), "UTF-8");
                System.out.println("---消费者---队列名：" + message.getMessageProperties().getConsumerQueue() + "，消息：" + msg
                    + ",deliveryTag：" + message.getMessageProperties().getDeliveryTag());
                channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);;
            }
        });
        return container;
    }
}