RabbitMQ简介

消息中间件的作用：解耦、冗余存储（持久化）、扩展性、削峰、可恢复性、顺序保证、缓冲、异步通信。

RabbitMQ是采用Erlang语言实现的AMQP（高级消息队列协议）的消息中间件。

RabbitMQ的特点：可靠性（持久化、传输确认、发布确认）、灵活的路由（交换器进行路由）、扩展性（集群）、高可用性（设置镜像）、多种协议（AMQP、STOMP、MQTT）、多语言客户端（Java、C#、Python、Ruby、PHP）、管理界面、插件机制。

management plugin插件的访问端口是15672，guest这个账号默认只能通过本地网络localhost访问，远程网络访问受限。

生产者客户端代码示例：

package com.lmy.demo.rabbitmq.demo;

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.MessageProperties;

public class RabbitProducer {
    private static final String EXCHANGE_NAME="exchange_demo";
    private static final String ROUTING_KEY="routingkey_demo";
    private static final String QUEUE_NAME="queue_demo";
    private static final String IP_ADDRESS="127.0.0.1";
    private static final int PORT=5672; //rabbitMQ 服务端默认端口号为5672
    public static void main(String[] args) throws Exception {
        ConnectionFactory factory=new ConnectionFactory();
        factory.setHost(IP_ADDRESS);
        factory.setPort(PORT);
        factory.setUsername("root");
        factory.setPassword("root");
        Connection connection=factory.newConnection();//创建连接
        Channel channel=connection.createChannel();//创建信道
        //创建一个type="direct"、持久化的、非自动删除的交换器
        channel.exchangeDeclare(EXCHANGE_NAME,"direct",true,false,null);
        //创建一个持久化、非排他的、非自动删除的队列
        channel.queueDeclare(QUEUE_NAME, true, false,false,null);
        //将交换器与队列通过路由键绑定
        channel.queueBind(QUEUE_NAME, EXCHANGE_NAME, ROUTING_KEY);
        //发送一条持久化的消息；hello world
        String message="Hello world";
        channel.basicPublish(EXCHANGE_NAME, ROUTING_KEY, MessageProperties.PERSISTENT_TEXT_PLAIN,
                message.getBytes());
//        //关闭资源
//        channel.close();
//        connection.close();
    }
}

消费者客户端代码：

package com.lmy.demo.rabbitmq.demo;

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

import com.rabbitmq.client.Address;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Consumer;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import com.rabbitmq.client.AMQP.BasicProperties;

public class RabbitConsumer {
    private static final String QUEUE_NAME="queue_demo";
    private static final String IP_ADDRESS="127.0.0.1";
    private static final int PORT=5672;
    public static void main(String[] args) throws Exception {
        Address[] addresses=new Address[]{
                new Address(IP_ADDRESS,PORT)
        };
        ConnectionFactory factory=new ConnectionFactory();
        factory.setUsername("root");
        factory.setPassword("root");
        //这里的连接方式与生产者的demo略有不同，注意辨别区别
        Connection connection=factory.newConnection(addresses);//创建连接
        final Channel channel=connection.createChannel();//创建信道
        channel.basicQos(64);//设置客户端最多接收未被ack的消息的个数
        Consumer consumer=new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope,
                    BasicProperties properties, byte[] body) throws IOException {
                System.out.println("recv message:"+new String(body));
                try {
                    TimeUnit.SECONDS.sleep(1);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
                channel.basicAck(envelope.getDeliveryTag(),false);
            }
        };
        channel.basicConsume(QUEUE_NAME,consumer);
        channel.basicConsume(QUEUE_NAME, false, "myConsumerTag",new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope,
                    BasicProperties properties, byte[] body) throws IOException {
                String routingKey=envelope.getRoutingKey();
                String contentType=properties.getContentType();
                
            }
        });
        //等待回调函数执行完毕之后，关闭资源
        TimeUnit.SECONDS.sleep(5);
        channel.close();
        connection.close();
    }
}

推荐使用继承DefaultConsumer的方式来实现消费，不推荐使用QueueingConsumer的方式来实现消费。