RabbitMQ (三)消息的发布于订阅

前面的两节中，主要介绍的都是一个生产者对应一个消费者，但是有时候是一个生产者对应多个消费者，这时候，我们就应该使用RabbitMQ的消息发布于订阅功能。

生产者：

import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Channel;
public class ClientSend2 {
    private static final String exchange_name="my_exchange";
    private static final String exchange_type="fanout";
    public static void main(String[] args)
    throws java.io.IOException{
        ConnectionFactory factory=new ConnectionFactory();
        factory.setHost("localhost");
        factory.setVirtualHost("my_mq");
        factory.setUsername("zhxia");
        factory.setPassword("123456");
        Connection connection=factory.newConnection();
        Channel channel=connection.createChannel();
        channel.exchangeDeclare(exchange_name, exchange_type); //声明exchange,以及类型
        String message="This mesaage is just for test!"+Math.random();
        channel.basicPublish(exchange_name, "", null, message.getBytes()); //将消息绑定了队列
        System.out.println("Message send:"+message);
        channel.close();
        connection.close();
    }
}

消费者：

import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.QueueingConsumer;
public class ClientReceive2 {
    private static final String exchange_name="my_exchange";
    private static final String exchange_type="fanout";
    public static void main(String[] args)
    throws java.io.IOException,java.lang.InterruptedException{
        ConnectionFactory factory=new ConnectionFactory();
        factory.setHost("localhost");
        factory.setVirtualHost("my_mq");
        factory.setUsername("zhxia");
        factory.setPassword("123456");
        Connection connection=factory.newConnection();
        Channel channel=connection.createChannel();
        channel.exchangeDeclare(exchange_name, exchange_type);
        //创建两个队列，将它们都绑定到同一个exchange
        String queue_name1=channel.queueDeclare().getQueue();
        channel.queueBind(queue_name1, exchange_name, "");
        String queue_name2=channel.queueDeclare().getQueue();
        channel.queueBind(queue_name2, exchange_name, "");
        System.out.println("Wait for message received!");
        //创建两个消费者，分别与两个队列相关联
        QueueingConsumer consumer1=new QueueingConsumer(channel);
        channel.basicConsume(queue_name1, true, consumer1);
        QueueingConsumer consumer2=new QueueingConsumer(channel);
        channel.basicConsume(queue_name2,true, consumer2);
        //两个消费者分别从各自的队列里面收取消息
        while(true){
            QueueingConsumer.Delivery deliver=consumer1.nextDelivery();
            String message=new String(deliver.getBody());
            System.out.println("Message received[consumer1]:"+message);
            QueueingConsumer.Delivery deliver1=consumer2.nextDelivery();
            String message1=new String(deliver1.getBody());
            System.out.println("Message received[consumer2]:"+message1);
            Thread.sleep(500);
        }
    }
}