RabbitMQ的安装及入门

什么是消息中间件？

消息队列中间件(Message Queue Middleware,简称为MQ)是指利用高效可靠的消息传递机制进行与平台无关的数据交流，并基于数据通信来进行分布式系统的集成。通过提供消息传递和消息排队模型，它可以在分布式环境下扩展进程间的通信。

消息中间件的作用

• 解耦
• 存储
• 扩展性
• 削峰
• 可恢复性
• 顺序
• 缓冲
• 异步通信

Linux环境下安装RabbitMQ

这里我们使用docker对RabbitMQ进行安装
启动docker,执行以下指令，即可安装RabbitMQ

docker run --name rabbitmq -p 5672:5672 -p 15672:15672 -d rabbitmq

安装完毕后，添加新用户（默认账户guest默认只能通过localhost进行访问)
添加新用户，用户名为"root" 密码为"root"

rabbitmqctl add_user root root

为root用户设置所有权限

rabbitmqctl set_permissions -p / root ".*" ".*" ".*"

设置root用户为管理员的角色

rabbitmqctl set_user_tags root administrator

Spring集成RabbitMQ

注意，这里引入的包为amqp-client,主要用于手动调用amqp的方法，来理解整个通信模型。

<dependency>
    <groupId>com.rabbitmq</groupId>
    <artifactId>amqp-client</artifactId>
    <version>4.2.1</version>
</dependency>

Hello World

• 生产者代码

package com.xjm.rabbitmq;

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

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

public class RabbitProducer {
    //交换机名称
    private static final String EXCHANGE_NAME = "exchange_demo";
    //路由key
    private static final String ROUTING_KEY = "routingkey_demo";
    //队列名称
    private static final String QUEUE_NAME = "queue_demo";
    //ip地址
    private static final String IP_ADDRESS = "192.168.11.131";
    //端口
    private static final Integer PORT = 5672;

    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setHost(IP_ADDRESS);
        connectionFactory.setPort(PORT);
        connectionFactory.setUsername("root");
        connectionFactory.setPassword("root");
        //创建连接
        Connection connection = connectionFactory.newConnection();
        //创建信道
        Channel channel = connection.createChannel();
        //创建type为direct,持久化的，非自动化删除的交换机
        channel.exchangeDeclare(EXCHANGE_NAME,"direct",true,false,null);
        //创建一个持久化的，非排他的，非自动删除的队列
        channel.queueDeclare(QUEUE_NAME,true,false,false,null);
        //将交换机与队列进行绑定
        channel.queueBind(QUEUE_NAME,EXCHANGE_NAME,ROUTING_KEY);
        //发送消息
        String message = "Hello,World!";
        channel.basicPublish(EXCHANGE_NAME,ROUTING_KEY, MessageProperties.PERSISTENT_TEXT_PLAIN,message.getBytes());
        //关闭资源
        channel.close();
        connection.close();
    }

}

• 消费者代码

package com.xjm.rabbitmq;

import com.rabbitmq.client.*;
import jdk.nashorn.internal.ir.CallNode;

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

public class RabbitConsumer {
    private static final String QUEUE_NAME = "queue_demo";
    private static final String IP_ADDRESS = "192.168.11.131";
    private static final Integer PORT = 5672;

    public static void main(String[] args) throws IOException, TimeoutException, InterruptedException {
        Address[] addresses = new Address[]{new Address(IP_ADDRESS,PORT)};
        ConnectionFactory connectionFactory = new ConnectionFactory();
        connectionFactory.setUsername("root");
        connectionFactory.setPassword("root");
        //创建连接
        Connection connection = connectionFactory.newConnection(addresses);
        //创建信道
        Channel channel = connection.createChannel();
        //设置客户端最多接收未被ack的消息个数
        channel.basicQos(64);
        //使用DefaultConsumer的方式实现消费
        Consumer consumer = new DefaultConsumer(channel){
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                System.out.println("recv message:"+new String(body));
                try {
                    TimeUnit.SECONDS.sleep(1);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                channel.basicAck(envelope.getDeliveryTag(),false);
            }
        };
        channel.basicConsume(QUEUE_NAME,consumer);
        //等待回调函数执行完毕后，关闭资源
        TimeUnit.SECONDS.sleep(5);
        channel.close();
        connection.close();
    }
}