消费端自定义监听

之前的例子里，我们消费者监听消费消息都是下面这样写的，一个while死循环，然后consumer.nextDelivery()一个个获取消息 。（初学者傻傻方式，哈哈）

后面我们就可以通过自定义消费监听者，来实现消息的消费了

步骤：

1. 创建一个自定义的消息处理类（如MyConsumer类）
2. 继承DefaultConsumer
3. 重写handleDelivery方法

代码：

生产者

package com.vivo.demo1.consumer;

import com.rabbitmq.client.*;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

/**
 * @author:luzaichun
 * @Date:2020/12/22
 * @Time:23:34
 **/
public class Producer {
    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setVirtualHost("/");
        factory.setPort(5672);
        factory.setHost("192.168.3.7");

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

        channel.addReturnListener(new ReturnListener() {
            @Override
            public void handleReturn(int replyCode, String replyText, String exchange, String routingKey, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("消息路由到queue失败。body=" + new String(body));
            }
        });
        for (int i = 0; i < 3; i++) {
            channel.basicPublish("test_exchange", "test.abc", true, null, "自定义消费监听测试".getBytes());
        }

    }
}

消费者

package com.vivo.demo1.consumer;

import com.rabbitmq.client.*;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

/**
 * @author:luzaichun
 * @Date:2020/12/22
 * @Time:23:38
 **/
public class Consumer {
    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setVirtualHost("/");
        factory.setPort(5672);
        factory.setHost("192.168.3.7");

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

        channel.exchangeDeclare("test_exchange","topic",false,false,null);
        channel.queueDeclare("test_queue",false,false,false,null);
        channel.queueBind("test_queue","test_exchange","test.#");

        //偷懒可以直接new一个DefaultConsumer，然后Override里面的handleDelivery方法
        /*channel.basicConsume("test_queue",true,new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                super.handleDelivery(consumerTag, envelope, properties, body);
                System.out.println("body="+new String(body));
            }
        });*/

        //创建一个MyConsumer类，继承DefaultConsumer，重写handleDelivery方法
        channel.basicConsume("test_queue",true,new MyConsumer(channel));
    }
}

消费监听处理类

	package com.vivo.demo1.consumer;

import com.alibaba.fastjson.JSONObject;
import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;

import java.io.IOException;

/**
 * @author:luzaichun
 * @Date:2020/12/22
 * @Time:23:50
 **/
public class MyConsumer extends DefaultConsumer {
    /**
     * Constructs a new instance and records its association to the passed-in channel.
     *
     * @param channel the channel to which this consumer is attached
     */
    public MyConsumer(Channel channel) {
        super(channel);
    }

    @Override
    public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
        super.handleDelivery(consumerTag, envelope, properties, body);
        System.out.println("获取到消息=======");
        System.out.println("envelope="+ JSONObject.toJSONString(envelope));
        System.out.println("body="+new String(body));
    }
}

测试结果：