RabbitMQ-订阅模式publish/subscribe
1.订阅模式模型
- 一个生产者 多个消费者
- 每个消费者都有自己的队列
- 生产者没有直接把消息发送给队列,而是先发送给交换机exchange
- 每个队列都要绑定到交换机上
- 生产者发送的消息是经过交换机的,然后到达队列,就能实现一个消息被多个消费者消费
应用场景: 比如注册之后需要发送邮件 同时需要发送短信
生产者
package com.ithzk.rabbitmq.ps;
import com.ithzk.rabbitmq.utils.RabbitMQConnectionUtils;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import java.io.IOException;
import java.util.concurrent.TimeoutException;
/** * @author hzk * @date 2018/3/10 */
public class Send {
private final static String EXCHANGER_NAME = "test_exchange_fanout";
public static void main(String[] args) throws IOException, TimeoutException {
Connection connection = RabbitMQConnectionUtils.getConnection();
Channel channel = connection.createChannel();
// 分发
channel.exchangeDeclare(EXCHANGER_NAME,"fanout");
String msg = "hello exchange";
channel.basicPublish(EXCHANGER_NAME,"",null,msg.getBytes());
System.out.println("Send msg"+msg);
channel.close();
connection.close();
}
}
消息丢失了,因为交换机没有存储的能力,rabbitMQ中只有队列有存储能力,此时还没有队列绑定到该交换机上,所以数据丢失了。
消费者1
package com.ithzk.rabbitmq.ps;
import com.ithzk.rabbitmq.utils.RabbitMQConnectionUtils;
import com.rabbitmq.client.*;
import javax.sound.midi.Soundbank;
import java.io.IOException;
import java.util.concurrent.TimeoutException;
/** * @author hzk * @date 2018/3/10 */
public class Recv1 {
private static final String QUEUE_NAME="test_queue_fanout_email";
private final static String EXCHANGER_NAME = "test_exchange_fanout";
public static void main(String[] args) throws IOException, TimeoutException {
//获取连接
Connection connection = RabbitMQConnectionUtils.getConnection();
//从连接中获取频道
final Channel channel = connection.createChannel();
//声明队列
channel.queueDeclare(QUEUE_NAME,false,false,false,null);
//绑定队列到交换机 转发器
channel.queueBind(QUEUE_NAME,EXCHANGER_NAME,"");
//保证一次只发一个
channel.basicQos(1);
DefaultConsumer consumer = new DefaultConsumer(channel) {
@Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
String msg = new String(body, "utf-8");
System.out.println("[1] Recv msg:" + msg);
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
System.out.println("[1] done");
channel.basicAck(envelope.getDeliveryTag(), false);
}
}
};
boolean autoAck = false;
channel.basicConsume(QUEUE_NAME,autoAck,consumer);
System.out.println("[Consumer 1 start]");
}
}
消费者2
package com.ithzk.rabbitmq.ps;
import com.ithzk.rabbitmq.utils.RabbitMQConnectionUtils;
import com.rabbitmq.client.*;
import java.io.IOException;
import java.util.concurrent.TimeoutException;
/** * @author hzk * @date 2018/3/10 */
public class Recv2 {
private static final String QUEUE_NAME="test_queue_fanout_sms";
private final static String EXCHANGER_NAME = "test_exchange_fanout";
public static void main(String[] args) throws IOException, TimeoutException {
//获取连接
Connection connection = RabbitMQConnectionUtils.getConnection();
//从连接中获取频道
final Channel channel = connection.createChannel();
//声明队列
channel.queueDeclare(QUEUE_NAME,false,false,false,null);
//绑定队列到交换机 转发器
channel.queueBind(QUEUE_NAME,EXCHANGER_NAME,"");
//保证一次只发一个
channel.basicQos(1);
DefaultConsumer consumer = new DefaultConsumer(channel) {
@Override
public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
String msg = new String(body, "utf-8");
System.out.println("[2] Recv msg:" + msg);
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
System.out.println("[2] done");
channel.basicAck(envelope.getDeliveryTag(), false);
}
}
};
boolean autoAck = false;
channel.basicConsume(QUEUE_NAME,autoAck,consumer);
System.out.println("[Consumer 2 start]");
}
}
和交换机绑定的队列都会收到消息