04 rabbitmq之Publish/subscribe

在介绍了rabbitmq的Work queues模式之后，这一节我们将阐述它的Publish/subscrige的用法。

1、前提约束

• 已经完成rabbitmq的第一个简单的测试程序
  https://www.jianshu.com/p/77bfc4fe5a1a
• 2、操作步骤
  我们马上要测试的rabbitmq的工作模式如下：
  
• 在src/main/java文件夹下创建包net.wanho.rabbitmq.pubsub
• 在net.wanho.rabbitmq.pubsub创建Sender.java

package net.wanho.rabbitmq.pubsub;

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

public class Sender {

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("127.0.0.1");
        factory.setPort(5672);
        factory.setUsername("guest");
        factory.setPassword("guest");
        factory.setHost("localhost");
        String exchange_name = "logs";
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();
        channel.exchangeDeclare(exchange_name, "fanout");
        String message = "hello3";
        channel.basicPublish(exchange_name, "", null, message.getBytes("UTF-8"));
        System.out.println("send:" + message);
    }
}

• 在net.wanho.rabbitmq.pubsub创建Receiver.java

package net.wanho.rabbitmq.pubsub;

import com.rabbitmq.client.*;

import java.io.IOException;

public class Receiver {

    public static void main(String[] argv) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("127.0.0.1");
        factory.setPort(5672);
        factory.setUsername("guest");
        factory.setPassword("guest");
        factory.setHost("localhost");
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();
        String exchange_name = "logs";
        channel.exchangeDeclare(exchange_name, "fanout");
        String queueName = channel.queueDeclare().getQueue();
        channel.queueBind(queueName, exchange_name, "");

        DefaultConsumer consumer = new DefaultConsumer(channel) {
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
                //交换机
                String exchange = envelope.getExchange();
                //路由key
                String routingKey = envelope.getRoutingKey();
                //消息id
                long deliveryTag = envelope.getDeliveryTag();
                //消息内容
                String msg = new String(body, "utf-8");
                System.out.println("receive message:" + msg);
            }
        };
        channel.basicConsume(queueName, true, consumer);
    }
}

• 测试
  启动Receiver两次，启动Sender一次，两个Receiver都能收到消息。
  以上就是我们完成的rabbitmq的publish/subscribe模式的测试。