rabbitMQ的简单实例——amqp协议带数据回写机制

rabbitMQ是一种高性能的消息队列，支持或者说它实现了AMQP协议（advanced message queue protocol高级消息队列协议）。

下面简单讲一讲一个小例子。我们首先要部署好rabbitMQ，然后实现一个生产者—消费者，生产者向rabbit中发布一个消息，消费者去rabbit取这个消息，在正确收到这个消息后，消费者会通过返回队列回写通知生产者自己收到了消息。

windows下部署rabbit非常简单，先安装erlang运行时，然后安装rabbitMQ安装文件即可，都是exe的，很简单。然后找到rabbit的sbin目录里的bat即可启动rabbitMQ。

下面是producer—consumer代码：

package com.hzfi.rabbitmq;

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

import com.rabbitmq.client.AMQP.BasicProperties;
import com.rabbitmq.client.QueueingConsumer.Delivery;
import com.rabbitmq.client.ShutdownSignalException;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.ConsumerCancelledException;
import com.rabbitmq.client.QueueingConsumer;

public class Producer {
    private final static String QUEUE_NAME = "myQueue"; //上送队列
    
    public static void main(String[] args) throws IOException, TimeoutException{
        String replyQueueName = null;   //返回队列名
        
        ConnectionFactory connFactory = null;
        Connection conn = null;
        Channel channel = null;
        try{
        connFactory = new ConnectionFactory();
        connFactory.setHost("localhost");
        conn = connFactory.newConnection();
        channel = conn.createChannel();
        //返回队列
        replyQueueName = channel.queueDeclare().getQueue();
        QueueingConsumer consumer = new QueueingConsumer(channel);
        channel.basicConsume(replyQueueName, true, consumer);

        String corrId = java.util.UUID.randomUUID().toString(); //用来表示返回队列结果的id,唯一
        BasicProperties props = new BasicProperties.Builder().correlationId(corrId).replyTo(replyQueueName).build();
        String msg = "linyang@hzfi.cn";
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        channel.basicPublish("", QUEUE_NAME, props, msg.getBytes());
        System.out.println("producer has published: "" + msg + """);
        
        while(true){
            Thread.sleep(1000);
            Delivery delivery = consumer.nextDelivery();
            System.out.println("from server reply:" + new String(delivery.getBody()));
        }
        }catch(IOException ioe){
            ioe.printStackTrace();
        }catch(TimeoutException toe){
            toe.printStackTrace();
        } catch (ShutdownSignalException e) {
            e.printStackTrace();
        } catch (ConsumerCancelledException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally{
            if(channel!=null)   channel.close();
            if(conn!=null)  conn.close();
        }
    }
}

package com.hzfi.rabbitmq;

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

import com.rabbitmq.client.AMQP.BasicProperties;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.QueueingConsumer;
import com.rabbitmq.client.QueueingConsumer.Delivery;

public class Consumer {
    private final static String QUEUE_NAME = "myQueue";
    public static void main(String[] args) throws IOException, TimeoutException{
        ConnectionFactory connFactory = null;
        Connection conn = null;
        Channel channel = null;
        try{
        connFactory = new ConnectionFactory();
        connFactory.setHost("localhost");
        conn = connFactory.newConnection();
        channel = conn.createChannel();
        channel.queueDeclare(QUEUE_NAME, false, false, false, null);
        System.out.println("listening for event message...");
        
        QueueingConsumer consumer = new QueueingConsumer(channel);
        channel.basicConsume(QUEUE_NAME, true, consumer);
        while(true){
            Thread.sleep(1000);
            Delivery delivery = consumer.nextDelivery();
            BasicProperties props = delivery.getProperties();
            BasicProperties reply_props = new BasicProperties.Builder().correlationId(props.getCorrelationId()).build();
            String msg = new String(delivery.getBody(),"utf-8");
            System.out.println("receive msg:" + msg);
            String retMsg = "ok, give you reply：" + new String(msg.getBytes(),"utf-8");
            System.out.println("Consumer中的返回队列名" + props.getReplyTo());
            channel.basicPublish( "", props.getReplyTo(), reply_props, retMsg.getBytes());
        }
        }catch(IOException ioe){
            ioe.printStackTrace();
        }catch(TimeoutException toe){
            toe.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally{
            if(channel!=null)   channel.close();
            if(conn!=null)  conn.close();
        }
    }
}

 开启RabbitMQ的后台管理服务（是个web页面）

     sbin>rabbitmq-plugins enable rabbitmq_management

     访问地址 http://localhost:15672/     id/psw: guest/guest

     可以对队列，用户，权限等进行管理，例如，默认情况下密码是任意，如上代码所示，ConnectionFactory仅仅设置了主机名，并未设置用户名和密码。

     我们可以新建或修改一个用户名和密码，如下图：

这样，我们上面的代码也要做相应的调整：

ConnectionFactory connFactory = new ConnectionFactory();
connFactory.setHost("localhost");
connFactory.setUsername("guest");
connFactory.setPassword("123");