RabbitMQJava系列4-Publish/Subscribe

Posted 2020-12-25 zytiger

发布订阅模式

X：交换机（转发器）

生产者把消息发送到交换机，交换机把消息发送到队列中，队列需要绑定到交换机。

1，一个生产者，多个消费者

2，每个消费者都有自己的队列

Java代码实现

生产者

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

import com.rabbitmq.client.BuiltinExchangeType;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.zy.rabbitmq.util.ConnectionUtil;

/**
* 发布/订阅模式
* 消息生产者
*
* @author zy
*
*/
public class Send {
private static final String EXCHAGNE_NAME = "test_exchange_fanot";

public static void main(String[] args) throws IOException, TimeoutException {
// 获取连接
Connection connection = ConnectionUtil.getConnection();
// 从连接中获取一个通道
Channel channel = connection.createChannel();
// 交换机声明
channel.exchangeDeclare(EXCHAGNE_NAME, BuiltinExchangeType.FANOUT);
String msg = "发布/订阅消息!";
// 发送
channel.basicPublish(EXCHAGNE_NAME, "", null, msg.getBytes());
System.out.println("send msg:" + msg);
channel.close();
connection.close();
}
}

消费者1

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

import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Consumer;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import com.zy.rabbitmq.util.ConnectionUtil;

/**
* 消费者消费消息
*
* @author zy
*
*/
public class Receive {

private static final String QUEUE_NAME = "test_queue_fanout_email";

private static final String EXCHAGNE_NAME = "test_exchange_fanot";

public static void main(String[] args) throws IOException, TimeoutException {
// 获取连接
Connection connection = ConnectionUtil.getConnection();
// 从连接中获取一个通道
final Channel channel = connection.createChannel();
// 队列声明
channel.queueDeclare(QUEUE_NAME, false, false, false, null);
// 绑定队列到交换机
channel.queueBind(QUEUE_NAME, EXCHAGNE_NAME, "");
channel.basicQos(1);
// 基于事件
Consumer consumer = new DefaultConsumer(channel) {
@Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties,
byte[] body) throws IOException {
String message = new String(body, "UTF-8");
System.out.println(" receive email msg:" + message);
channel.basicAck(envelope.getDeliveryTag(), false);
}
};

// 监听队列
channel.basicConsume(QUEUE_NAME, false, consumer);
}

}

消费者2

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

import com.rabbitmq.client.AMQP;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Consumer;
import com.rabbitmq.client.DefaultConsumer;
import com.rabbitmq.client.Envelope;
import com.zy.rabbitmq.util.ConnectionUtil;

/**
* 消费者消费消息
*
* @author zy
*
*/
public class Receive2 {

private static final String QUEUE_NAME = "test_queue_fanout_sms";

private static final String EXCHAGNE_NAME = "test_exchange_fanot";

public static void main(String[] args) throws IOException, TimeoutException {
// 获取连接
Connection connection = ConnectionUtil.getConnection();
// 从连接中获取一个通道
final Channel channel = connection.createChannel();
// 队列声明
channel.queueDeclare(QUEUE_NAME, false, false, false, null);
// 绑定队列到交换机
channel.queueBind(QUEUE_NAME, EXCHAGNE_NAME, "");
channel.basicQos(1);
// 基于事件
Consumer consumer = new DefaultConsumer(channel) {
@Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties,
byte[] body) throws IOException {
String message = new String(body, "UTF-8");
System.out.println(" receive sms msg:" + message);
channel.basicAck(envelope.getDeliveryTag(), false);
}
};

// 监听队列
channel.basicConsume(QUEUE_NAME, false, consumer);
}

}

 

总结：发布/订阅模式需要队列绑定到交换机，不定义路由键

参考：http://www.rabbitmq.com/tutorials/tutorial-four-java.html