rabbitMq简单入门

背景

RabbitMQ是一个由erlang开发的AMQP(Advanved Message Queue)的开源实现

应用场景

• 异步处理
• 应用解耦（服务解耦）

API

下载rabbitMQ自己看

简单实战搭建

• 生产者

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import java.io.IOException;
import java.util.concurrent.TimeoutException;

/**
 * @author create by yingjie.chen on 2018/3/27.
 * @version 2018/3/27 14:54
 */
public class Producer {
    public static void main(String[] args) throws IOException, TimeoutException {
        //创建连接工厂
        ConnectionFactory factory = new ConnectionFactory();
        factory.setUsername("admin");
        factory.setPassword("admin");
        //设置 RabbitMQ 地址
        factory.setHost("172.16.7.45");
        //建立到代理服务器到连接
        Connection conn = factory.newConnection();
        //获得信道
        Channel channel = conn.createChannel();
        //声明交换器
        String exchangeName = "hello-exchange";
        channel.exchangeDeclare(exchangeName, "direct", true);


        String routingKey = "hola";
        //发布消息
        byte[] messageBodyBytes = "quit".getBytes();
        channel.basicPublish(exchangeName, routingKey, null, messageBodyBytes);

        channel.close();
        conn.close();
    }
}

• 消费者

import com.rabbitmq.client.*;
import java.io.IOException;
import java.util.concurrent.TimeoutException;
/**
 * @author create by yingjie.chen on 2018/3/27.
 * @version 2018/3/27 15:17
 */
public class Consumer {
    public static void main(String[] args) throws IOException, TimeoutException {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setUsername("admin");
        factory.setPassword("admin");
        factory.setHost("172.16.7.45");
        //建立到代理服务器到连接
        Connection conn = factory.newConnection();
        //获得信道
        final Channel channel = conn.createChannel();
        //声明交换器
        String exchangeName = "hello-exchange";
        channel.exchangeDeclare(exchangeName, "direct", true);
        //声明队列
        String queueName = channel.queueDeclare().getQueue();
        String routingKey = "hola";
        //绑定队列，通过键 hola 将队列和交换器绑定起来
        channel.queueBind(queueName, exchangeName, routingKey);

        while(true) {
            //消费消息
            boolean autoAck = false;
            String consumerTag = "";
            channel.basicConsume(queueName, autoAck, consumerTag, new DefaultConsumer(channel) {
                @Override
                public void handleDelivery(String consumerTag,
                                           Envelope envelope,
                                           AMQP.BasicProperties properties,
                                           byte[] body) throws IOException {
                    String routingKey = envelope.getRoutingKey();
                    String contentType = properties.getContentType();
                    System.out.println("消费的路由键：" + routingKey);
                    System.out.println("消费的内容类型：" + contentType);
                    long deliveryTag = envelope.getDeliveryTag();
                    //确认消息
                    channel.basicAck(deliveryTag, false);
                    System.out.println("消费的消息体内容：");
                    String bodyStr = new String(body, "UTF-8");
                    System.out.println(bodyStr);

                }
            });
        }
    }
}

原理

1. Client 用过EXCHANGE 指定routingkey 就能找到消息所在的队列Queue
2. Client 订阅就是监控绑定的的队列，有消息会直接取到，消费者处理完返回信息原理也是一样，通过不一样的队列（一般都是queue后面加个queueName_xxxx）